lorawan nanogateway pytrack gps

  • Hello everyone,
    I have a fipy connected to a pytrack board, I am using the setup as a lorawan nano gateway. The programming is such that it picks GPS location and builds the payload adding the location as part of the udp packet

    def _make_node_packet(self, rx_data, rx_time, tmst, sf, bw, rssi, snr):
            lat, long = getloc()
            RX_PK["rxpk"][0]["time"] = "%d-%02d-%02dT%02d:%02d:%02d.%dZ" % (rx_time[0], rx_time[1], rx_time[2], rx_time[3], rx_time[4], rx_time[5], rx_time[6])
            RX_PK["rxpk"][0]["tmst"] = tmst
            RX_PK["rxpk"][0]["freq"] = self._freq_to_float(self.frequency)
            RX_PK["rxpk"][0]["datr"] = self._sf_bw_to_dr(sf, bw)
            RX_PK["rxpk"][0]["rssi"] = rssi
            RX_PK["rxpk"][0]["lsnr"] = snr
            RX_PK["rxpk"][0]["lat"] = lat
            RX_PK["rxpk"][0]["long"] = long
            RX_PK["rxpk"][0]["data"] = ubinascii.b2a_base64(rx_data)[:-1]
            RX_PK["rxpk"][0]["size"] = len(rx_data)
            return ujson.dumps(RX_PK)

    this is the sample packet sent to the server

    [   597.437] Received packet: {"rxpk": [{"rfch": 0, "freq": 868.1, "long": 36.77718, "data": "QA0AABcARwcBD+JLPezpX6pRMFTl0A2O4d12u6SftNVgOEE/uRKh7rUm", "lsnr": 6.0, "codr": "4/5", "datr": "SF12BW125", "time": "2018-12-05T06:25:59.808526Z", "modu": "LORA", "size": 42, "lat": -1.29687, "tmst": 994609182, "stat": 1, "chan": 0, "rssi": -48}]}

    It works but occassionally I get this output on the console:

    Guru Meditation Error: Core  1 panic'ed (LoadProhibited)
    . Exception was unhandled.
    Register dump:
    PC      : 0x400fd268  PS      : 0x00060e30  A0      : 0x800ddda4  A1      : 0x3ffdbc90
    A2      : 0x00000001  A3      : 0x00000001  A4      : 0x00000000  A5      : 0x00000001
    A6      : 0x00000000  A7      : 0x00060023  A8      : 0x800fc05a  A9      : 0x3ffe70f0
    A10     : 0x00000001  A11     : 0x00000001  A12     : 0x3f94fe00  A13     : 0x3f94fe00
    A14     : 0x3ffe7260  A15     : 0x3ffe71c0  SAR     : 0x00000020  EXCCAUSE: 0x0000001c
    EXCVADDR: 0x00000001  LBEG    : 0x4009b414  LEND    : 0x4009b41f  LCOUNT  : 0x00000000
    Backtrace: 0x400fd268:0x3ffdbc90 0x400ddda1:0x3ffdbcb0 0x400dde0b:0x3ffdbcd0 0x400de2d1:0x3ffdbd00 0x40108a7e:0x3ffdbd20 0x400f4fbe:0x3ffdbd50 0x400f1945:0x3ffdbd80 0x400fcd33:0x3ffdbda0 0x400f5048:0x3ffdbe40 0x400f1945:0x3ffdbe80 0x400fcd33:0x3ffdbea0 0x400f5048:0x3ffdbf40 0x400f1945:0x3ffdbfc0 0x400f1972:0x3ffdbfe0 0x400de363:0x3ffdc000 0x400de634:0x3ffdc0a0 0x400dd345:0x3ffdc0c0 

    i also get this log

    [   597.870] Downlink timestamp error!, t_us: 4292846312

    plus some very long core dump. What could be causing this issue?

  • @rcolistete thank you for the pointer I have tried and no problems so far I'll give it a couple of days before sending it to the wild :)

  • Try using :

    import gc

    the last line in some parts of the nanogateway code. Maybe is out of memory issue creating that error.

Pycom on Twitter