Employees For a Morning

Last Wednesday Kirsten and Bexie joined me in the AMOS development lab (i.e. our family basement) as part of "Bring Your Kid to Work Day". Their first task was to design and build a boat out of cardboard, glue, and duct tape, and see how "seaworthy" it was in our bathtub. Bexie opted for a surfboard type of design, which used only a couple of pieces of cardboard:

It was quite stable, moved well in the water, and was able to carry quite a few coins of "ballast". It definitely out-performed my boat which was not at all stable, and quickly filled with water and sank. Kirsten's boat was similarly stable, but was able to carry more coins due to its three dimensional construction and increased buoyancy. Here is a video that Kirsten took and edited. She opted to go all out on the video editing 😏:

The second task was to solder some wires from a wireless transceiver (the RFU220SU from Synapse (https://synapsewireless.com/resources/core-technology/)) to a USB-RS232 breakout board. Essentially the goal was to see if we could assemble our own wireless startup kit using $50 in parts rather than the $300 or so that it would cost for a commercial version. After taking two minutes to transfer all of my soldering "know-how" they got to it and did a great job. At first when we tried it out in the Synapse software, the wireless transceiver did not get detected, but I had read somewhere that there was a possibility that the RX / TX labels on the breakout board could be incorrectly assigned, so we tried reversing them and voila, it worked - the software detected the board, and we were able to see the various parameters associated with it.

For the third task, I showed them some sections of code in the Android "Boat Captain" software that I wanted to change over to allow it to specify a rudder angle and propeller speed instead of the left and right propeller speeds that the previous version of AMOS required. They did a great job on this also.

The rest of the week was not as fun without my co-workers, but I did manage to get a pair of the Synapse wireless transceivers working, sending data back and forth between my PC and AMOS at 115200 bps. I also modified the main AMOS software to be able to use this wireless serial link and started modifying the PC version of the "Boat Captain" software to do the same. At some point I would like to do a "range test" of these transceivers to see if they can really get anywhere close to the three mile line of sight range that their spec sheet claims. These transceivers also have a lot of extra processing and I/O capabilities beyond basic communications, eg: A to D inputs, digital I/O, PWM outputs, etc. so the one connected to AMOS could be used for measuring voltages, currents, and even acting as a sort of hardware "watchdog" for AMOS to make sure that it is still functioning correctly. If not, it could execute a hard reboot of the Pi board to get it up and running again.