Tuesday, March 24, 2015

More Tasks for the Raspberry

As shown in the previous post, I have been working with the Raspberry PI 2 Computer Board. Thus far I have Connect a Camera and Servos to point the camera. In time, this will become a Roving Robot (more on that in a future post).

Also, I have been waiting for the Raspberry to grow large enough to run the OpenCPN Navigation software for my Boat. Previously, it was ran on a LapTop (which is now old and klunky).

Previous hardware Raspberry PI configurations (A, B, B+) did not have enough RAM nor CPU speed to make any of that that really possible. The Raspberry PI 2, with its 2x RAM, 4x Processors (which provide about 6x Speed). is a good match for the Boat's Navigation requirement. I do not have all of the details worked out yet, but it appears do able (that will be a subject of another blog post).

To make Boat Navigation and Rover Robot possible I need a network connection between the Raspberry PI and my Tablet. The boat navigation software runs on the PI and displayed on the Tablet. The PI will be in the Roving Robot with Camera display and Controls at my Tablet.

There are several pieces of software need to make all of this possible, most are readily available.  The Center piece is the  WIFI Access Point, with it I can connect Tablet directly (ah, . .  via WIFI) to the Raspberry PI, and when the PI is connected to my home Internet (i.e., during development) I can enjoy normal Internet access. Obviously, on the Boat and while Roving as a Robot, the Internet connection may not be available.

Adafruit has a nice tutorial which is helpful when setting up the Raspberry PI as a WIFI Access Point. With only a little head scratching, I got it and the attending DHCP up and running.  My internal home private is 192.168.2.xx, the new PI private address is 192.168.4.xx.  The PI routers between the two. Once set up, it was easy to attach my Cell Phone and Tablet to the new PI WIFI network.

Access to the devices and files on the Raspberry PI private network from my home network can easily be accoumplished with the "sshuttle" command, "rp22" is the name of my Raspberry.

$ sshuttle -DNHr rp22

The OpenCPN Navigation Software is ran on the PI, in a virtual "vncserver" window. The window is configured to match the aspect ratio (600x900) of the Tablet.

I use "ssh" to access the PI and execute the "vncserver" command. Once set up, what ever is running, will continue to run even when a viewer is disconnected, the next connection just continue the previous session. With the "-alwaysshared" option, multiple viewers can be connected simultaneously. This will be very convenient for both the Boat and the Rover.

$ vncserver -alwaysshared -geometry 600x900 :3

I use "vncviewer" on the Tablet (and/or cell phone) to view the results.

OpenCPN running on The Raspberry PI
and Displayed on the Tablet

As can be seen below with "xosview", the Raspberry PI 2 is just idling along.

System Resource Report
For the Roving Robot I will use the PI to operate the Camera pointing Servos and eventually control wheels. Currently I am streaming the camera's video to my Tablet.

All of this functionality is useful and will be used on several of my projects, including my Minima Transceiver (see many previous posts). I plan to write software to provide a Remote Panel for the Minima.

Boat Camping

During last years Boat Camping trip to the San Juan Islands,  I had 8 adults and their attending kids on board my Boat. Most camped overnight on shore.

They all had there personal devices and after the first night, they all needed to be re-charged. We had a few USB Chargers in the Boat, but there was a line waiting to gain access, I had little time on the charger myself.

For this next year, I plan to install MotorCycle USB Chargers in several places on the Boat. One will be installed on the Bridge, where I can use it with the Tablet and Navigation Software.

MotorCycle USB Charging Ports

More details to follow - while having fun with the Raspberry PI !

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

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