A proper way of doing read callback receive with Arduino LoRa

Arduino LoRa is a great library that brings LoRa support (SX1276/SX1277/SX1278/SX1279) to Arduino world. I'm using it in my Crossbow LRS project (still not stable enough for flight, work in progress). Until now, the biggest problem with this library I've found is that examples suggests that heavy protocol processing inside interrupt callback is fine.

Unfortunately, it is not. It can lead to unexpected processing delays, create conflicts with other interrupts, bus clashes and other hard to debug things. This is why, the better way is to do packet reading (and processing) inside main loop and use read callback only to set a flag. Like this:

Only please remember to set all variables modified in ISR routine as volatile.

Generate S.Bus with Arduino in a simple way

Did you noticed that lately I write about radios quite often? Well, I do and it's not a coincidence. Proper introduction for what I'm working on will happen in a next few days, but now I will only write that this will be a mid-range, cheap, DIY radio link for UAVs. By mid-range I mean up to 5km. So, it will be positioned somewhere between 2.4GHz systems and full sale LRSes like DragonLink or TBS Crossfire.

Back to business. I've discovered, that there is very little in The Internet how to generate S.Bus with Arduino. OK, there are few libraries for reading Futaba S.Bus protocol like mikeshub/FUTABA_SBUS or zendes/SBUS but the only library made simple I've found is bolderflight/SBUS. Too bad it works only with Teensy devices. So, after a few hours of hard work, reading code of OpenTX, MultiWii, INAV, reading RcGroups and final help of Konstantin Sharlaimov (Digital Entity of INAV), I give you:

Generate S.Bus packets with Arduino in a simple way

But first, few simple facts:

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JavaScript PID controller

I suppose this is the first time programing topic came up on this blog. Probably not the last time, since this is what I do most of the time.

While working on serial port usage balancing for INAV Configurator I’ve quite accidentally created a PID controller in JavaScript. Maybe it’s not the most advanced PID controller ever, but has all the things required:

  • computes P-term
  • computes I-term
  • computes D-term
  • has output limiting
  • has I-term accumulator limiting

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