WIFI for Our Projects

I remember reading (many years ago); With the invent of the Internet, we would eventually have many in-home devices that would be addressable and controlled via an IP Address. The prediction suggested that even the common Light Bulb would someday be networked.

To date, there are many "computer devices" that are controlled via an IP Address, and many of them are connected via WIFI.

But so far, many Light Bulbs (or LED) still do not have IP Addresses.  The big reason for this is the expense of the compute power needed by each addressable device. A computer or controller is needed to perform the complex network functions, like; TCP/IP Stack, DHCP. Authentication, and General Data Transfer. For most hobby project developers, the complex networking software development is the most difficult impediment.

But, a relatively new device, the TI CC3000MOD (at $20.00) does all the network hard stuff at a relatively low cost. The CC3000 is programmed and data is sent to/from a project device via a simple two wire SPI interface. The actual chip is a little hard to work with, because of its physical small size, board layout, antenna requirements, and soldering methods.

But, Adafruit.com has a new product which uses the CC3000 to make it easy to include WIFI Networking in a controller project.  (Yes I know, my blog is starting to sound like a Adafruit commercial, but they are one of the leaders, and provide some great inexpensive project components. And, No, as stated in other blogs entries, I do NOT work for them. I just really like some of their products.)

Adafruit CC3000 Breakout Board, with Integrated WIFI Antenna *

The Adafruit.com CC3000 Breakout Board (at $35.00) is a small pre-assembled board that can be attached to any project with only a simple 9 pin header. Programming, control, and data transfer is via the 2 wire SPI interface. Complex TCIP/IP stack programming is NOT necessary, as all of the hard work is done by the chip and/or included libraries.

Note: other configurations are available which include external antenna connector and Protoboard space.

I plan to order a couple to experiment with for my future projects.


* As stated before, the photos has been taken from the Adafruit web site without their permission, hopefully they will not mind for this use and recommendation.


--

Trinkets

OK, my parts were received from Adafruit.com, see previous post.

The USB Power Gauge works as expected, it is very handy to check the charge rate on my Cell Phone, and for checking power consumed by any USB device, including my Raspberry Pie and/or the BeagleBone computers. The USB Power Gauge provides information that is otherwise a little difficult to obtain.

I had also purchased three Adafruit Trinkets. I followed the recommended software (Ardunio IDE) install instruction, and modification needed for the Trinket. And then, I proceeded to "Brick" all three Trinkets (or at least that is what I thought). I have used the Ardunio Interactive Development Environment (IDE) many times in the past and was not expecting any problems.

Because the "Trinket" has only 512 Bytes EEPROM (boot loader ROM) part the loader (about 1.5K bytes) is placed in FLASH RAM, which leaves about 5.5K bytes for user programs.

While loading a user program into the remaining FLASH RAM, if something goes wrong, part of the boot loader can be overwritten, and therefore it is somewhat easy to "Brick" the Trinket.

Instructions are provide to "UnBrick" the Trinket, but that requires yet another Arduino and downloaded programs.

While reading many pages on the web trying to understand my problem, I discovered that for Linux machines may not support USB in the way that the Arduino IDE for the Trinket desires. The recommended method is to use a external USB Hub to connect the Trinket to a Linux computer.

It worked, . . . how or why, I do not know !!

The Trinkets were NOT actually Bricked, . . . they just looked and acted like it. While plugged into a Hub, they now respond as desired by the Arduino IDE.

My first task was, of course, to run "Blinky", the "Hello World" program.

Once that worked, I quickly put together the following CW sketch to send/blink "CQ" on the LED.

/*
  This Sketch Blinks CQ on the LED
*/
 
int led = 1; // blink 'digital' pin 1 - AKA the built in red LED

int WPM = 13; // Words Per Minute
int ditTime = 1200 / WPM;
int dahTime = ditTime * 3;

// the setup routine runs once when you press reset:
void setup() {
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);
  delay(2000);

}

// the loop routine runs over and over again forever:
void loop() {

    for(int j = 0; j < 3; j++) {
      dah(); // C
      dit();
      dah();
      dit();
      eoc();
      
      dah(); // Q
      dah();
      dit();
      dah();
      eoc();
    }
    eow();
    
    delay(10000);
}


void eoc() { // End of Charactor
    delay(ditTime * 3); // added to previous End-of-Char time
}

void eow() { // End of Word
    delay(ditTime * 7); // added to previous End-of-Char time
}

void dit() {
    cwpulse(ditTime);
}

void dah() {
    cwpulse(dahTime);
}

void cwpulse(int duration) {
    digitalWrite(led, HIGH); 
    delay(duration);
    digitalWrite(led, LOW);
    delay(ditTime);
}


// End   

A more complete and non-trivial CW sketch would be table driven, but this was quick-n-dirty just to just get something to work.

More complex and interesting programs will hopefully follow.

I think the Trinket will have a place in my bag of tricks, for small Ham Radio Projects. I am currently thinking of maybe a Beacon Trinket Shield, and/or a Tennis Ball Launcher Trigger Controller.

--

New Products I Plan to Order

There are two new little products that will make my planned projects easier, both less than $10 each.

The first is a little (inline) USB Power Gauge:

I have several (many) small battery-powered devices that are Charged or Powered via their mini or micro USB connection. For example: a cell phone, mini speakers, keyboards, video cameras, micro-controllers (e.g., Rpi), and several others. I think standardization of chargers and/or power for some devices is great for users, but.

I find that sometimes information is lacking regarding the state, or status, of the device being charged. The devices idiot power LED does not always tell the story. On some devices, the battery does not seem to take-a-charge, or it charges very (maybe too) slowly. The charge rate is typically dependent on the USB charge voltage, the active Application current draw while the device is being charged, or some other unknown reason. I have waited overnight for something to be charged and disappointed with the results the next morning. Without a meter it is difficult to know what is going on, or how to fix the problem.

Adafruit.com is producing a new "USB Power Gauge *" and it will be inexpensive. I plan order one when they are available (in maybe 10 days or so).

Adafruit USB Power Gauge *

The second new little product is a small "Adafruit Trinket"; an Arduino-Like Project Controller:

The Adafruit Trinket has some very interesting spec's, and will be just the right size, with a small pin count, for some projects that I have in mind. With this controller and a simple Arduino Script, all of our Ham projects can be made "smart".  The Trinket can be purchased for 5 Volt or 3.3 Volt circuits. I will include several of these when I place the order from Adafruit.com.

 Adafruit Trinket - A Very Small Project Controller *

* Images were obtained from the Adafruit.com's Web Site, without their permission. Hopefully they will not mind for this endorsement. I do not work for Adafruit, I just really like some of "Lady Ada's" products.

---

UPDATE: Oct 17, 2013
Parts are now on order.
I also added the following to the order:
Heatsink Thermal Tape - http://www.adafruit.com/products/1468
Heatsink - http://www.adafruit.com/products/1493


--

RS Clip Leads

Recently while working on my Boat, I was tracing, replacing, and testing some indicator lights on the DC Control Panel. Most of the original plastic lights holders were broken at the panel. I decided to replace all of the indicator lights with LEDs.  While at the local Radio Shack store to pick up a single White LED, I notices they have a nice neat pack of four 30 inch Clip Leads - just what I needed to help with the task. And besides, a set of clip leads could be handy to have on the boat.

Radio Shack - Clip Leads

But DANG!, the Radio Shack Clip Leads are almost impossible to use, the plastic shield around the clips is very slick inside, and trying to clip on to something is almost impossible. The clip rotates inside the shield when trying to open the jaws. WHAT A PAIN!  I wonder how the "uses test" designer engineer, managed to build such a useless product !

Out of frustration, I quit using the Clip Leads.

Later while thinking about the manufacturing process and thinking that they may have put a "release agent" within the shield to help de-mold them. Maybe they used something like Silicon Grease?

What was needed for my Clip Leads, was a way to remove the release agent, or change the inside texture. I thought about that a while, . . . and came up with an easy workable solution.

I put a sprinkle of "Sandblasting Grit" inside each shield.

It worked like a champ!

Although, I was a little worried about transporting a small plastic bag of white powder (grit) to the boat :-)

--

Routers

The last few days, I have been in "Router Hell" or "Router Heaven", with a little Amateur Radio thrown in ( but, . . . it all depends on your perspective ! ).

I have two "routers", one in my Shop/Hanger, and one in my Boathouse. The two sites are about 12 miles apart. Each router has had it own difficulties that I should have corrected before this.

For the last few months (actually longer than that), I have been having problems with my Shop network. It sometimes would get very slow, my connection from the Shop to the Internet is via;

1. First, a short RF hop to my neighbors house,
2. another RF longer hop to the local ISP house.
3. and then a long RF link to a mountain about 10 miles away,
4. then another RF Link back down the mountain (another 10 miles) to the Longhaul ISP servers shop,
5. and then wires into the city of Everett, where it finally meets the Internet.

As you can see it is not exactly a pretty sight.

But, because I do NOT have good tools or insight to the actual Radio Links, it is difficult for me to test the network and know where there is difficulty. Just when I feel I-have-had-enough, it starts working very well and I forget my frustrations.

The WiMax connection at the Boathouse is also slow, but I attributed that to my CLEAR Wire Modem location, which is necessarily located in a window between metal boathouses, with only a small RF window to an unknown tower location. Sometime it is slow and miserable to work with. The Boathouse Router/WiFi Access Point (WRT-54G) is directly connected to the CLEAR modem. The Security Configuration prevents others from using my allotted bandwidth.

Then, it finally it happened, . . . the Shop/Hanger Router stopped working, a 100% Failure - it was NOW time to fix things.

My local ISP (a support guy in the airpark), gave me another "used and different router" to try. He provide the basic configuration and checkout, but I would have to configure it for the "non-standard" way that I use routers. At first, it seamed difficult to find the router admin web pages to configure the functions that I needed. But a Google search (to the rescue) provided the information I needed, and a lot, - LOT more. My "new" router is a "Buffalo WHR-G54S Air Station" and it uses an Open System operating system, known as "DD-WRT".

With the new found information, I was able to easily configure my router with:

• WiFi Station Channel and Security
• NAT (Network IP Address Translation)
• PAT (Application Port Address Translation and Redirection)
• DHCP
• DHCP, with some preassigned Static IP for a few devices

Google provided lot of additional information, like; how the DD-WRT can be downloaded to many standard commercial routers - Including the router that I use a the Boathouse.

One difficulty that I had in the past with my old router at the Boathouse, I could not configure my router to do "PAT" and therefore I could only have one device that would occupy a single inbound port. For example: "ssh" uses port 22, but I wanted to place several devices (e.g., Raspberry Pie and Beaglebone computers) in the Boathouse. I could have done it, but each would have to be specially configured to use yet another port for similar services. Which means each would be unique and difficult to quickly manage. Ideally, port management is done via "PAT" in the router where it belongs. My dumb old Boathouse router can not do "PAT".

Plus, by the end of the month, CLEAR will no longer support Static IP for my area, I will have to reconfigure my Domain Name to use Dynamic DNS, that is if I want to continue to use and access the Boathouse via "network known" addresses. I have already figured out the necessary changes to the CLEAR modem configuration.

So, I downloaded the Open Source "DD-WRT" for my router, with "only" some difficulties. I now have a new OS running on my router in the Boathouse, using all of the above service and configurations. I have already moved my Rpi web server to its new location, with a little Dynamic DNS service magic, it appears as always at: "http://rpi.wa0uwh.com:8040".

Google also provided another interesting Amateur Radio use of routers, via the Open Source efforts started by the DD-WRT group. The routers are being reconfigured as a "Mesh Network", very similar to the old "Packet Radio" network (I think I have my facts straight). As it turns out WiFi channels 1-6 overlap the Amateur Band, and therefore the devices can be used via "part 97". I need to learn more about this.

So, a short story - made long, after several days of work, . . . all-is-well with my routers (or as good they have ever has been).

Now, it is time for more reading about "Northwest Mesh Networks" !

--

Larry's Hall Effect Project

Tuesday my friend, Larry - KB7KMO, came by for a visit and work in my shop.

Larry has been sailing around the world in his sailboat for that last few years. He returns to the Seattle area to see his grand kids and families. We try to get together at least once, each time he is in town.

For this visit, Larry had several projects that we worked on in the shop. He was in need of a way to monitor the output of his generator and/or other power sources that replenish his battery banks.

The Artwork and Toner Transfer
Ready to Etch

There are may commercial products that would work, but Larry wanted to try a custom solution. For this he has found several DIY projects that suggested Hall Effect devices to monitor current.

What was needed was a small DIY PCB to hold the Hall Effect device and the few other devices that provide the input for a monitor and display.

This PCB will be mounted on-or-near the power source. The Hall Effect device that Larry will be using is shown setting on the right edge of the PCB.

My previously used and blogged Toner Transfer PCB method was used to build the necessary remote boards. We used Inkscape to create the original artwork.

Larry Cutting the Reverse Side
Toner Transfer Image

Etching is simple; put the PCB in a ZipLoc Freezer Bag, with a small amount of Ferric Chloride, and then knead while under running hot water. For a 1 oz copper clad, the process takes about 4 minutes.

Larry at the Sink, kneading the bag while running Hot water
over it, which is filled with Etch and His board

The Cut boards,
Ready for Drilling

The Hall Effect device can handle a lot of current (+100 Amps) and therefore large pads were necessary. Additional copper strap will be used to increase the current handling abilities.

This is the first time I have tried making Toner Transfer PCB with large pads or Ground planes,  on my projects I normally avoid them by using cross hatch grid for the Ground Planes. Space for some small capacitors are also included for line conditioners at the remote.

Board Inspection

Larry will finish this project, when he returns to his boat, . . . somewhere on some distant, exotic tropical island paradise !

--

My Low Pass Filters

With repairs of my boat almost complete, I can return to some Ham Radio projects.

The following are the files and artwork that I have used to create the Low Pass Filter, see my previous blog posts. As previously posted, the value of components were selected from junk box parts which are a close match as computed. The artwork is provide here as an ".svg" file suitable for use with Inkscape or other vector graphics programs. The intent is to allow space for as many identical parallel capacitors as necessary to provide the correct values. The coils are wound and measured as necessary. PCB SMA edge connectors are soldered on both sides of the PCB and are used to make connections easy.

30m Low Pass Filters

Inkscape SVG Low Pass Filter Artwork

My public URL of the SVG filer is: https://dl.dropboxusercontent.com/u/46313528/Published/OutputFilter_03.svg

Let me know if you build a Filter.

--

Been Working on Cyrene

I have NOT been in the Shack or working in my eShop much lately, I have been at the marina repairing my boat - Cyrene.

Cyrene on a Previous Cruise

Due to life's other duties and responsibilities, Cyrene has been neglected for several years. On our last boat trip, we had an engine or transmission failure. I did not know which, but I did know the repairs could be minor, or something major, Cyrene was stored afloat in the boathouse, . . . Well, now several (many) years later, it turns out to be major, which means $$$. My goal is to have Cyrene back on the water by May 1, ready for short cruises this summer.

Once Cyrene is repaired, and now that I am retired, I plan to operate my Ham Station form locations around Puget Sound, on the water as WA0UWH/m.

Puget Sound is a wonderful place to have a boat, there are many destination; marinas, bays, coves and anchorage. Also, easy access to Canadian inland water around Vancouver Island and Vancouver (city) is always a treat.

Cyrene Anchored Among the Stone Spirits
at Roscoe Bay Canada
(A few long years ago)

One of my favorite destinations is Roecoe Bay in Desolation Sound Canada. According to local lore, Stone Spirits lurk in the waters of the bay. And, often when the water is very still, rocks alone the shore reflect in the water as a mirror image. The reflection produces the illusion of a very long and symmetrical horizontal Totem Pole - A Stone Spirit. To see the effect, look at the shore line in the photo while tilting you head to the left.

Another of my favorite destinations is Prideaux Haven, also in Desolation Sound. The tidal exchange from the North and South, around Vancouver Island, meet near Prideaux Haven and therefore very little cold water from the ocean mixes with the warmer water found in this area. The warmer than normal water, makes for very good clear-sea-water swimming. An online Gallery of photos shows scenes of the area.

So far, work on the Cyrene has been fun. But, as everyone knows, . . . "A boat is just a hole in the water, in which to throw money".

UPDATE - May 20, 2013
Starboard Engine repaired, Cyrene went back into the water on May 2, but sea-trials found that the Starboard Engine would not go to full speed (3000 RPMs). The Injector Pump was removed and sent in for test, repair (if necessary), and calibration.  The theory is that a little salt water entered the "boost compensator" and stopped it from working.

UPDATE - July 4, 2013
Most repairs are done, I have parts for the GenSet, but will have to wait for time to install them. Two recent trips to the San Juan Islands have proven the repair to the Starboard Engine was very successful. At full throttle and 3200 RPM at 19.9 Knots GPS was available from both engines, my normal curse is at 2200 RPM at about 10 Knots.

--

RPi as a WSPR Beacon with PA47

---

UPDATE:
Sorry,  this did NOT work as expected, the Wsprrypi code is still being developed. The second fork of the program is available. The RF output of the of the RPi is less noisy if the DC supply is from a well filtered source.

---

I have previously built my Homebrew PA47 Power Amplifier for a Propeller Microprocessor Beacons (see previous selected posts). The Propeller provides 12mW to drive the PA.

The Raspberry Pi provides about the same output power via the Dan Ankers Wsprrypi program. Therefore. it was a simple mater of connecting to the correct pins on the RPi GPIO Connector to give it a try. Thanks Dan !

Here is my initial lash up, with just a Low Pass Filter (LPF).

RPi WSPR Beacon with LPF
Measure Output into 50 Ohms =  5dbm

Here is the RPi and the PA47, with input and output LPFs attached.

With the two low pass filters, the measured output is 9.4 V PP at a 50 ohm load, or 220mW, which is 23.4dbm. The Dan's WSPR program uses only about 3% of the CPU.

I have plans to modify Dan's Wsprrypi program to include other beacon modes (e.g., QRSS) similar to those that I have used with the Propeller Processor.

FYI, This my complete family of experimental PA47 Amplifiers.

My PA47 Family
Max Power - 1w, 5w and 15w

On the air, WSPR Received Reports will be added here.


-- Home Page: https://WA0UWH.blogspot.com

National Pi Day

Today, Mar 14, 2013 is National PI day.

When written as numeric today's date is 3/14, is similar to 3.14, which of course is the value of the first three digits of PI.

PI Day should be celebrated at 6:28 am, as that is the value of  "Tau", which is the value of  2xPI.

Today is also Albert Einstein's Birthday Anniversary (Mar 14, 1879) - PI Day is a well fitting tribute to a great man.

--

Rpi on the Network - Problem Fixed !

My Raspberry Pi is now back on the Network (see: my Rpi posts).

It has been offline, because I did not have an HDMI Display, and was not able to see the boot error messages. And, therefore I was not able to correct the boot problem.

I now have an HDMI Display, and have fixed the boot problem. The Rpi needed a simple "manual file system check" (i.e., fsck -y /dev/<disk>).

Currently my Rpi is back on the Network as before at: http://rpi.wa0uwh.com:8040/

The Rpi maybe on-or-offline the next few weeks as I try different system configurations.

--

Mom's Biscuits

This is post is not about Ham Radio, but about something else that I enjoy - eating good food.

Mom's Biscuits

On Saturday, Mom would have celebrated her 89 Birthday. And for that, I decided to try to make some Biscuits, the way she has done so expertly many time for our family Saturday morning breakfast (which was such a long time ago).

Mom was famous for her Biscuits and Pies. Nothing in the Cookbooks came close to; look, taste and texture of her baked goods. Her Biscuits were almost three inches tall, and very flaky, soft and crisp on the outside, she would always say: “I don’t know if they’l be fit to eat!” - but they were always, soooo . . . very-very good!

Somehow Mom’s always got the volume of dough just right, regardless how many people were eating. We would end up with just the right number of Biscuits for each person, plus one more. The last Biscuit was made from the trimmings, left over dough from the cutting process. My brother, two sisters and I, argued over who was to receive the highly prized Ugly Biscuit. For most of my childhood, Mom cut the Biscuits with a Red Handle Donut cutter (with the center hole cutter removed), later she switch and used an easy available drinking glass to make the cuts. This was way back in the good’old-days. when calories were NOT counted, . . . but Biscuits were.

I have tried several times in the past forty years to make Biscuits. The first time was while Mom was still alive, but that did not seem to help. My Biscuits always came out like the dreaded Hockey-Pucks. In fact, in my childhood family, there was a running joke; there were only two types of Biscuits; Mom’s, and Hockey-Pucks. Somewhere along the way, my sisters, seemed to have learned how to make Biscuits, but I had not.

Lately, I have been thinking about Mom’s Biscuits, I think I have always had the ingredients about right, although Mom never really followed a recipe. She would say; put in some of this and that, mix it up, knead it with your palm, pat it out flat, cut the Biscuits, and don’t play with the dough. I think her “technique and style” was more important than the ingredients. Maybe, I had just NOT learned the "technique and style" part of making Biscuits.

As stated, I have been thinking about Mom’s Biscuits, and thinking about how fast she worked at; the mixing, kneading, folding, cutting, and the fast clean up of the mess. Now, while remembering, I can still see her work at each step, and that is what I am now trying to duplicate with my new Biscuit making efforts.

Mom would have pre-heated the oven to 350 degrees F, although she would never wait for the oven to reach the set temperature. Once in the oven, a timer was NOT used, the Biscuits came out of the oven about 10 seconds before we were to set down to eat. To this day, I do not know how she timed meals so expertly.

I do not have a standard oven, for my baking efforts, I have a rotating Pizza Oven, on which I have cooked almost everything - it works better than expected for an oven. I have used it to cook some very good Brownies. My Biscuit efforts will cooked on the Pizza Oven.

Several weeks ago, I first tried the Pizza Oven for Biscuits with what I remember of Mom’s Biscuit recipe, but as usual, I got Hockey-Pucks. The puck tasted OK, but Tess (my dog) liked the pucks better than I.

Now, with my new appreciation for Mom's “Technique and Style”, I am trying again, with much better results.

I don't know if they'l be fit to eat !

.

Biscuits In the Oven

Mom's Biscuits were typically larger diameter (depending on the water glass she used as the cutter), for my first attempt my biscuits are smaller and leaned over as they cooked. For the next batch, I will find something larger to use for the cutter.

More Biscuits to be Saved For Later

Note: the obligatory Ugly Biscuit in the center.

There will be Biscuits left over and saved for later.

BTW. this batch of Biscuits were pretty Darn Good, but not exactly how I remembers Mom's. A little more thinking and practice is needed.

Now, the mess needed to be cleaned up, this is something Mom would have done within seconds, after the Biscuits were in the oven.

It is a Big Mess, . .  but it was worth it !

Thanks Mom, . . . for the great memories, . . . and Happy Birthday !


--

Rpi on the Network - NOT !

Sometime today my networked RPi died, not sure why, but I will not have time to fix/rebuild it until later this week. At last count it had served web requests from 213 remote users. See previous post.

The RPi file system and log files still exists and can be mounted on another system for review.

I hope it was not Hacked!

More info later.

---

UPDATE
The RPi is back on the Network as http://rpi.wa0uwh.com:8040/, but it maybe up or down depending on my experiments.

--

Rpi Backup

My Rpi is working very well (as shown on previous post). My many years of Admin'ing UNIX systems is paying off.

I have spent several hours / days configuring the system, building a web page, and playing with use ideas. I do NOT want to lose any of my efforts due to a dumb mistake or system crash - so a backup is needed.

Several backup strategies are suggested in the web forums, the most often mentioned method is; shutting down the Rpi system, and cloning the SD card. Which I think is a good idea - but maybe only once in a while. The size of my 16GB SD card and system interruption precludes doing this very often.

Most of the Rpi system is easily re-built from the original image, and most (if not all) other system additions are obtained from online software depots.

After building (cloning) the original SD image, and like most Rpi users, I expanded the file system size to fill the rest of the SD card. And then executed the following:

sudo aptitude update
sudo adduser --system <my-desired-user-name>

And, of course, I had to install "fldigi" for a potential radio connection.

sudo aptitude fldigi

Now, . . . I really do not need a full backup, just the backup important stuff. A very clever backup command is "rsync", which I have used many times on very large systems. Rsync can be installed as:

sudo aptitude install rsync

With the following rsync command,  I can backup a few important directories to another remote linux system, in this case a system called "shilo", from the local (Rpi) system is called "magpi". The directories that I want to backup are: "etc", "boot", "home", "root", and "var/spool/cron".

(
  cd / &&
  rsync -avzR --delete etc boot home root var/spool/cron  shilo:/Backup/magpi/SnapShot01
)

The nice thing about "rsync" is that the backup files are easily accessed via "scp" or directly on the remote machine. Also, re-executing the same command, will only transfer the files that have been changed. See the rsync manual page.

--

Rpi on the Network

As mentioned in the previous post, I now have my Raspberry PI (Rpi) connected to the Network, serving Web Pages and providing (my) access via SSH and Remote Desktop.

Only one wire is needed for this configuration, that is the 5 Volt power from a 1 Amp wall wart. Network access is via the USB WiFi Adapter as shown in the photo. This Rpi can be accessed from anywhere in the world as http://Rpi.WA0UWH.com:8040 . Currently it is serving only a single web page, other fun pages (or links) will be added later.

Rpi running a Web Server, SSH, and Remote Desktop
http://Rpi.WA0UWH.com:8040

My plans include connecting the Rpi to an Ensemble Receiver (SDR), which can be done with only the addition of an Antenna and USB Sound Card.

I am considering moving the Rpi and the SDR to a remote location (where I have WiFi access) so that I can Transmit from my Shack, without overloading the SDR. This remote location will be good for remote QRSS Grabber operation.

I am impressed with the Rpi, it is a fun system.


-

A Piece of the PI

Several days ago, I received an e-mail from Adafruit informing that they had Raspberry PI boards available, I had been on their waiting list for several weeks. Once ordered it was only a few days before the PI arrived - yesterday.

I spent several hours reading the "Getting Started" web information pages. I did not purchase a pre-loaded SD card as I have several.

Some Lessons learned

• The micro USB connector is only used for power (+5V).
• It is difficult to use the PI if you do not have a HDMI display, but it is possible to run the PI without a display, but when first starting and not knowing what to expect, it was difficult to know that it was actually working (or NOT). Now I know that the 5 LEDs blink and flash when booting. Initially I had a bad SD card and nothing was working. A working PI boots in about 30 seconds with all LEDs flashing.
• Thanks to information found on the web, a static address can be forced (for easy access via SSH), by editing the "/etc/network/interfaces" while the SD card is mounted on another system, I used 192.168.2.40

Orignial file: /etc/network/interfaces

auto lo

iface lo inet loopback

iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

File changed to:

auto lo

iface lo inet loopback

#iface eth0 inet dhcp

auto eth0
iface eth0 inet static
address 192.168.2.40
netmask 255.255.255.0
gateway 192.168.2.1
dns-nameservers 192.168.2.1

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

Soon, I will replace the Ethernet cable with a WI-FI adapter, and replace the Micro USB +5V supply connection with a battery. I will then have a stand-alone portable networked system. I will probable only use SSH, VNC, and remote X11 windows to access the PI.

I think I will like the PI, it boots fast and with an USB audio adapter it will be useful for my Ham Radio adventures with SDR and other radio controls.

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UPDATE - Feb 21, 2013
With the following command, I installed "fldigi"

• aptitude install fldigi

I do not have a USB sound adapter installed yet, but "fldigi" runs with my minimal configuration!

I need to get a stand-alone USB wall wart to power the PI (or a battery) and a USB expander to connect other USB devices (i.e., sound adapter), the PI has only a minimal amount of current it can supply to external USB devices. Other web doc's suggests a powered USB Expander is required.

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UPDATE - Feb 22, 2013
I returned the "/etc/network/interfaces" file to original configuration, and then modified my home router config to serve my desired IP Address for the PI's MAC address via DHCP. The advantage here is the PI will have a known IP Address while on my Network, but will obtain any an available DHCP IP Address when at any other location.

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UPDATE - Feb 25, 2013
I now have the PI serving web pages, as: http://Rpi.WA0UWH.com:8040

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UPDATE - Feb 27, 2013
My PI is now using an WiFi connection to the network, only the single power connection wire is connected to the PI. The power cord could be replaced with a Battery for a completely portable PI web server.

I used information found at: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=26&t=26795. The only difference is that I set up to use a Static IP Address as configured and served via DHCP from my WiFi Router.

---

UPDATE - Mar 10, 2013

Sometime today my Rpi died, not sure why, but I will not have time to fix/rebuild it until later this week. At last count it had served a connection for 213 users via web requests.

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PA47 Now Ready for On The Air Tests

Thus far I have NOT connected my PA47 Amplifier to an antenna, because I was not sure of it output harmonic content (see previous posts).

Last night at our monthly P&C group meeting, Wayne - NB6M presented a demonstration of his new DSA815 Rigol Spectrum Analyzer with one of his oscillators and the effects of a output filter devices. His filter completely eliminated (down into the noise floor) any harmonic content.

As a second example and demonstration, I provided the PA47 Amplifier and a LowPass filter. A 50 Ohm load and 40db tap was used to reduce the input to the Analyzer. Actually, both the 1 Watt and the 15 Watt versions of the PA47 were checked, the results were about the same.

The 1 Watt and 15 Watt Version of PA47

The output filter that I used, is a simple Chebyshev 5 Pole Filter (as previously posted).

30m LowPass Filter as Designed with LtSpice

The filter was originally designed via an Online Filter Design program, and then available multiple 330pF 1206 SMD caps were used to obtain the nearest values, 3 caps for each end, and 4 for the center. The cores were wound as necessary by measuring the results on an AADE LC meter.

30m LowPass Filter as Implemented

The Results

Wayne declared the PA47 fit for Amateur Radio Service. The second harmonic was down 51db and the third was down 67db from the fundamental.

PA47 Connected to
DSA815 Rigol Spectrum Analyzer

I will soon connect the 1 Watt version of the PA47 to an Antenna, and use if for QRSS Beacon Service on 10.140050MHz (+-50).

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More 0402 Thermistors

In preparation of loading and testing the next revision of my PA47 Amp, I have started the process of joining FET and Thermistors, by mixing the glue - JB-Weld epoxy (see: previous posts).

For this build, I am using only JB-Weld, for the initial tack and then for the final cover. The JB-Weld web site provided some interesting data regarding strength and temperature resistant abilities. It suggests that JB-Weld is the right "glue" for this Thermistor attachment process.

It appears that a little too much of JB-Weld was mixed, but is actually is just a small drop, most of it will not be used.

Microscope at 7X

Here are some FETs with Thermistors attached with small mounts of JB-Weld. Soldered wires will be added after the epoxy has set.

2N7000 with Thermistors Attached

While under the Microscope I noticed that JB-Weld is not what it appear to the un-aided eye, it is actually gray with black flecks.

This the same as the First Image, only the
Microscope Set at 15X

After curing, this glob of epoxy was subjected to a test with a hot soldering tip, confirmed that JB-Weld is much more heat tolerant than Hobby Fast Cure Epoxy.

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Use of a 0402 Size Thermistor

This post and project is keeping with my On-Going Goal of working on very small projects as long as my eyes and steady hands allow.

The Thermistor Fan Control Circuit is working very well for my PA47 RF Power Amplifier (see selected links to previous posts). The PCB was re-laid out to include the circuit. Initially for testing, I just used an available 10K NTC Thermistor super-glued to the heatsink on a 1 Watt PA47 configuration.

For this project, my plan is to attach a small 10K NTC 0402 size thermistor directly to the 2N7000 for best FAN Control and cooling of the FET.

Here are some Microscope photos of the attachment process.

Shown is the 0402 Thermistor super-glued to the back of the TO-92 2N7000, along with the tip of a standard X-Acto Blade (for additional size reference).

Attached 0402 Thermistor on a TO-92 2N7000

A Wire Wrap Wire (30 AWG) was then soldered on each end of the Thermistor.

Thermistor with Wires Attached

A small drop of Epoxy was added to cover the connections and support the attached wires. Epoxy does not stick to the Kynar (wire insulation) very well (if at all). The wire connections may need better/more support.

Waiting for the Epoxy to Cure

I used Fast Cure Hobby Epoxy, but it will take over night to harden completely, in circuit testing maybe started tomorrow.

I am not sure of the thermal conductivity of Hobby Epoxy, perhaps something else would be better? Maybe another harder Epoxy such as JB-Weld?

This is ALL probably not necessary, but I wanted to see if I could do it. For future projects and use of Thermistors will probably be a larger size, and maybe not attached directly to the FET.

--

Part Quest

I am always looking for Small Parts for my projects.

For most of my projects I have standardized on a simple Battery connector, it is the same style that is used in many of the Propeller and Arduino Products. The connector is shown here attached to my PA-47, which is a Homebrew 15 Watt HF PA.

The Battery Connector on 
My PA-47 Project

The actual connector that I have been using is a little different than those that are readily available. This connector has smaller tabs that are used to solder it to the PCB. Because the tabs are smaller, this same connector can be use with proto-breadboards (with only a little difficulty) . The tabs are not exactly the size the breadboard would like. but it works. Also, because the pins are little smaller they fit into round drilled holes in the PCB. Note: Most of my PCB suppliers do not allow plated slots as necessary for many other battery connectors.

My Favorite DC Connector
for  Projects
(unknown to me at the time,
this is a PJ-102A)

My stash of these connectors is almost depleted. Somewhere along the way, I got the (wrong) idea that these connectors were called "PJ-007".


A quick (causal) search via FindChips found the PJ-007 was only available from Digi-Key, I had several other parts that I had planned to order from Digi-key, so I ordered 20 each PJ-007's, for about $12.00

 The True PJ-007

Received, BUT NOT!  what I wanted !

I received the PJ-007's, they are a similar style of connector, but they are about 1/2 the size that I was expecting. My quick and "Causal" search was too quick - now I have a bunch of very small connectors that I will probable never use.

I would have to look to my other suppliers and/or try to remember where I had previously purchased the desired connectors.

After several days of searching and trying to remember, I eventually found my source at Adafruit. But, the search of the Adafruit site was not exactly easy, as this part did not match any key words that I tried. I finally gave up and looked at the complete list of available parts, but still no joy.

https://www.adafruit.com/products/80

I eventually found the connector on the Adafruit site as a "suggested part", while viewing the available 9 Volt Battery Clips (which is a nice clip with wires and a end connector).

But Adafruit description of the "suggested part" did not include a manufactures part number, there was just an order ID number - 373. I plan to add a few to my next Adafruit order.




But then:

While attempting to re-layout my PA-47 Board to correct and add some new features, I did a quick check of ALL of the parts and patterns before ordering a new set of boards. While looking at the Library part for the Battery Connector, I noticed that it included a spec sheet and URL for the connector. With a little research of the manufacture I found the desired part is a PJ-102A. A quick check of FindChips.com suggested the part is available from several suppliers.

Several PJ-102A are now on order.

Until next time, my small Parts Quest, . . .  goes on.

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My Online Password Management Solution

In the past

Managing my Online Account Passwords has been a time consuming tedious task. For the last few years I have tried many methods, and recently used a simple spread sheet, which was only available on one of my shop computes.

Because of fear of loss, exposure and/or theft, I have always typed my passwords into the spread sheet in simple (and crude) obscure format, that only I could mentally decipher (maybe).

Yet, I have always been concerned and nervous about password theft.

But Now

I have recently found "aWallet.org" which is an APP for my Android Cell Phone. it provides true AES/CBC "high level security" for my online Account Passwords. And, an emergency encrypted backup file can be created. For safe keeping, I copy the encrypted backup file to DropBox (a free cloud service). Because the backup is encrypted with a 256 bit encryption key, the data is safe on an un-encrypted online storage service, they claim it would take millions of years to crack the file.  For additional security, I use several files that are known as a HoneyPots.

With the DropBox phone APP, I can copy to the cloud the encrypted backup (of the password data) with a simple push of a few buttons. The backup file is then available on all of my connected DropBox computers. DropBox also has an Archiving Function that allows you to reclaim; deleted, lost, or previous versions of the files (within 30 days).

This is completely SAFE, I trust it even for my Banking passwords. If I lose my phone, the data can not be viewed without a "master pass code" (which is stored internally with the same encryption level). If you are still really concerned, you can elect to NOT make copies and/or optionally set up the aWallet pass code to "auto destruct" the Encrypted Password files if too may unlock attempts are tried.

If I buy a new phone, the DropBox copy of the encrypted file can be downloaded to the new phone and therefore used the same as before.

Note: as with any encrypted storage it is only as good as the secrecy of the "master pass code", make it unique from ALL other passwords, and ONLY known to you!

BTW: if you do not use DropBox - you SHOULD!

Dropbox is useful for many things, more than I can relate here (I use Dropbox for all of my projects reported on this blog). When you join, you get 2GB of VERY easy to use Cloud Storage space for FREE. Ask me for a DropBox Invitation, we each will get an additional free 500MB of DropBox storage space. If you install from the web without a friendly invitation, you will NOT get the additional free space. Send your request to my e-mail address as shown on my www.QRZ.com page. with subject: "DropBox Invitation". Encourage your friends to join DropBox and you and they will each receive additional 500MB of free space.

Besides, where else would you store all of your Ham Radio Online Passwords, for; QRZ, ARRL, qsl.net, etc, etc!


I am now a, very calm, Online Password - Happy Camper !

---

UPDATE

The new version of aWallet is available, aWallet-Cloud automatically does an encrypted backup to your Cloud server.


--

An Open Post to DipTrace for Menu Enhancement

As I have stated before, I use DipTrace for most (if not all) of my PCB projects posts on this blog. The major reasons that I use DipTrace are:

• I have a very small investment in Licenses.
• DipTrace runs well on my Linux workstations via WINE  (I do not have access to MS system).
• DipTrace provides one of the best High Resolution Copper Pours that I have found.
• DipTrace's recent Updated Software has solved many of my previous grips, see my DipTrace Survival Guide post.
• DipTrace is easy to learn and easy to promote to new users.
• Managing your own Library of parts is easy, once you learn all of the tricks.

With the latest DipTrace Software Update, and with the press of a single button, High Quality PCB's can be ordered (it is almost too easy, especially if you order before your are actually ready?). The included BayArea Circuits PCB Manufacturing Service is not the cheapest, but they are one of the fastest available in the USA,  they claim the default is 5 days plus post delivery time (and faster if you want to pay more).

The following is my recent Enhancement Request as posted on the Yahoo Group DipTrace Forum.

---

Default Menu Enhancement Request

One of the most accessible menus available with DipTrace PCB Layout is the "Right Mouse Click". The Default Menu is available when nothing is selected and available virtually at any place on the entire Display screen.

But, this severely under utilized Default Menu has only has two menu items available for selection; "Paste" and "Empty Clipboard", both of which I have never used.

I would like to see the following items added to this Default Menu:

0) ESC
1) Update ALL Copper Pours
2) Edit Traces
3) Route Manual(~)
4) Auto "ReRoute" Trace
5) Mirror while Bottom selected (very useful for backside edit and viewing)
6) F10

I know some of these are available at the Keyboard, or at the top menu, but productive is LOST with each long mouse excursion or attention diversion to the keyboard.

Currently, to use DipTrace, my left hand hovers over the ESC and 1,2,3,4 keys as these key functions are almost always needed to do anything. But other keyboard activity requires diversion of attention and could be best handled via menus.

NOTE: The above menu items are only a few that I would put into a "User Defined Menu" if the function was available.

There may be other menu items that other uses would suggest for this Default Menu.

Regards,
Eldon Brown

---

I am hopeful that we will see more Productivity, User Menus, and Library Access enhancements in the near future releases.

--

More Destructive Testing

But, . . . hopefully NOT.

With the breadboard FAN Control Circuit designed and working, I decided to do some more Destructive Testing of the PA-47 (see previous post).

The two tests that I had in mind were to; subject the PA to High VSWR, by; first, opening the end of the 18 inch coax, then second, putting a "short" on the end. These are the two extremes.

Initial Test - Normal Operation

• The PA and exciter were configured for normal operation of 12.6VDC.
• The Exciter provided 12 mWatts of drive at 10.140MHz to the PA input connector.
• The PA with Low Pass Filter were connected to a proper 50 Ohm Dummy Load via a 18 inch coax cable.
• DC input was 12.6 VDC at 2.54 Amps, or  32.1 Watts.
• Voltage measurements are taken at the output of the Low Pass Filter.
• The typical Low Pass output voltage is 75 Volts PP, or 14.1 RF Watts output.
• The FAN Control Circuit turns the FAN slowly.
• All is normal.

The Open End Coax Test

• DC input was 12.6 VDC at 1.34 Amps, or  16.8 Watts.
• The measured Low Pass Filter output voltage was 160 Volts PP.
• The danger here is the reflected voltage will exceed the voltage rating of the RF Power FET.
• Results: No apparent harm was done.

The Shorted End Coax Test

• DC input was 12.6 VDC at 3.11 Amps, or  38.2 Watts.
• The FET was getting HOT!
• Immediately the FAN Control Circuit put the FAN into Full High Speed mode.
• The measured Low Pass Filter output was 35 Volts PP (note: this is about 18 inches from the short).
• After about 10 seconds, the FET went into a kind of internal thermal shutdown on its own (I did not expect it to do its own shutdown).
• DC input was now 12.6 VDC at 3.54 Amps, or  43.6 Watts.
• Measure RF output went down to about 10 Volts PP.
• The PA was left to cook for about 30 seconds. I am not sure how long this could continue without permanent damage.
• Results: FAN at High Speed, FET was in Internal Thermal Shutdown, everything was getting HOT!

Conclusion

The FAN Control Circuit saved the day, no Blue Smoke was emitted. I think the FAN Control Circuit is a very good addition to the PA-47 !

After Cool Down, the 50 Load was reconnected and normal operation was resumed.

Although, .  . . the idle current is now 80 mAmps, where as before the tests, idle current was typically only 20 mAmps. Maybe the quality of the FET has diminished?


--

PA-47 with Fan Control

Today I breadboarded a FAN Control circuit for my PA-47 RF Power Amp (see previous post). I used a simple NTC Thermistor for the sensor, which will be attached to the FET on the Heatsink. The FAN Control circuit also supports a slight temperature bias when the TR Relay is activated.

The Thermistor can be seen attached to the FET

The breadboard FAN circuit has be running for several hour - working as expected, it cycles the FAN ON and OFF (with speed control) as the Beacon Exciter transmits on its six minute schedule. The RF output is connected to a dummy load, as I have not looked at the PA signal on a Spectrum Analyzer yet.

The Chaos of the Bench
Testing in Progress

My goal was to build the new PA with the additional FAN Control circuit small enough that it would fit the same 1 x 1.5 inch layout of the current PA-47. I had to rearrange a few parts to make it all fit.

While doing some experiments with a new layout with DipTrace, I tried laying it out as a four layer board. Four layers makes the circuit layout much easier. but it would be a lot more expensive ( about 3 to 4X ).

New two layer PA-47 boards with Fan Control are now on order.

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