Cycle race track lap counter

Sorry for the delay getting back to you on this... I'd be pretty sure the freezing itself stems from the device getting swamped with Bluetooth advertisements.

What happens is when an advertisment is received, it's poked into a queue in the interrupt, and handled by the event loop (where it is filtered). If the event loop doesn't manage to handle the items fast enough, then you hit FIFO_FULL and a bunch of issues stem from that.

The event loop should limit the amount of packets it executes such that timers still work when it's swamped with data, but maybe that is failing somehow and it's just sitting there trying to handle BLE packets.

jsble_exec_pending: Unknown enum type ...

This shouldn't happen with 2v09 and later firmwares, but it seems like the queue got full and then only part of a Bluetooth message was added to it, which then caused things to get really messed up. How many devices do you have broadcasting? If I can reproduce it here I might be able to fix that particular issue.

Looking at the code I think there are a few places you could help it out though. Mainly, you want the handler for setScan to be super fast, so you want as few function calls as possible (and to bail out as soon as possible if you don't care about the device). It looks like you have a few different function calls, and you could try something like:

function scanHandler(d) {
  var v = Velo.list[d.id];
  if (!v || !d.manufacturerData) return;

  Display.rxCnt += 1;

  v.rssi = d.rssi;
  v.bat = d.manufacturerData[0];

  switch (v.state) {
    case 0:
      v.state = 1;
      v.rxCount = 0;
      v.rssiMin = null;
      v.rssiMax = null;
      break;
    case 1:
      if(d.rssi >= CONST.RSSI_THRESHOLD) {
        v.state = 2;
        Led.flash();
      }
      break;
  }

  var t = getTime();
  v.tRssiLast = t;
  v.rxCount += 1;

  if(v.rssiMax == null || rssi >vthis.rssiMax) {
    v.rssiMax = rssi;
    if(v.state == 2) {
      v.tRssiMax = t;
    }
  }
  if(v.rssiMin == null || rssi < v.rssiMin) {
    v.rssiMin = rssi;
  }
}
// ...
NRF.setScan(
  scanHandler,
  {filters: [{manufacturerData: {0x0590: {}}}]}
);