It took longer than I’d hoped, but I have just released a firmware update for the I/O processor on the STM32-DVM-MTR2K V2.0 boards.
Those who watched it closely had asked the question why did I only connect 4 of the 8 Wild Card (user programable) GPIs to hardware inputs on the STM32-DVM-MTR2K V2.0? Here’s your answer: I was saving the other 4 as dedicated software inputs, as as of today, the firmware to make use of them has been released. For complete information, have a look at the official manual for the STM32-DVM-MTR2K I/O API. And if you’re looking up upgrade, you’ll also need the binary file to upload to the ATMega328P, which can be downloaded here. And if that weren’t enough links for you, then it’s probably a good idea for me to mention that there is an STM32-DVM-MTR2K information page that indexes all files, articles, tutorials, manual, etc. It’s exhaustive.
So what does this mean? It means that by closing the jumpers at JP7 (I/O Serial En.) the serial port on the ATMega328P I/O processor is connected to the 3rd serial port on the NanoPi NEO (/dev/ttyS2), and the ATMega328 can now communicate with the NEO. Want to get an e-mail if the VSWR goes high? Just write a script for the NEO and it’s done. Want to remotely change the output power on the MTR2000? Knockdown analog repeat? No problem, just have the NEO do that for you. The capabilities are pretty extensive.
The last teaser for those who have indicated a desire for more physical I/O lines is that if you look through the V2.0 manual, you’ll find both i2c interfaces on the ATMega328p and NanoPi NEO are connected to the system connector on the back of the station. How, without messing with the firmware on the board, physical I/O can be expanded too!