Hello,
Recently I've been working on setting up a BBB with a combined Moteino controlled MightyBoost and gateway. The whole device tree story complicates things a bit, but it works like a charm. Awesome product, Felix!
I just want to share the stuff I've been making for anyone wanting to do something similar. All files are available on https://github.com/ltj/bbb-mightyboost (https://github.com/ltj/bbb-mightyboost).
What it is:
- A device tree overlay for BBB that sets up the GPIO pins for the MightyBoost signals
- Boot script to load overlays (UART included) and set up gpio
- A small C++ program to monitor the shutdown pin and perform a shutdown
- A sketch for the Moteino on the MightyBoost that merges the functionality of the MightyBoost controller and the RFM69 Gateway. Note that packets are sent to the BBB using a slightly different format from the original GW sketch, and that other customizations may lurk in the code.
Not much documentation I'm afraid. I can highly recommend reading up on the Linux device tree if this is the first time you encounter it.
Sounds very cool, good to know BBB + MB play well together!
I plan to make some changes to the MB to reflect the necessity to move the bootOK signal to a analog pin (A0), as explained in the guide (http://lowpowerlab.com/mightyboost).
Thanks. Will definitely find more uses for the MightyBoost.
Quote from: Felix on January 28, 2015, 08:24:50 AM
I plan to make some changes to the MB to reflect the necessity to move the bootOK signal to a analog pin (A0), as explained in the guide (http://lowpowerlab.com/mightyboost).
I didn't solder on a wire to connect the bootok signal with A0, since my initial testing showed that the spurious voltage levels on the ARM pins during boot/shutdown has quite the opposite effect on the BBB. The level on the bootOK pin will be read immediately as HIGH by the Moteino, even before my script asserts the pin. This leads to the false, but harmless, assumption in the sketch that the BBB has booted - but that's ok. All it does is turning on the button led. On shutdown the voltage on the pin will go below the LOW threshold on the D7 input and the load can be safely disconnected. Moving the signal to A0 will however solve the first problem so it should be a nice change for both RPi and BBB :)
Cheers,
Lars