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

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.

--

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.

---

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.

---

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.

---

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

---

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.

--