diff options
| -rwxr-xr-x | python/experiments/decode_gps.py | 23 | ||||
| -rwxr-xr-x | python/igate.py | 5 |
2 files changed, 27 insertions, 1 deletions
diff --git a/python/experiments/decode_gps.py b/python/experiments/decode_gps.py new file mode 100755 index 0000000..da7904a --- /dev/null +++ b/python/experiments/decode_gps.py @@ -0,0 +1,23 @@ +#!/usr/bin/env python +import struct +from math import pow + +EXAMPLE_MSG = b"<\xff\x01HB9EGM-7>APLRT1,WIDE1-1:!/7%=6P\')8[I#Q" + +def decodeEncodedGPS(packet): + """Returns a string with decoded latitude and longitude, or raises ValueError""" + ix = packet.index(b":!/") + gps_packet = packet[ix+3:] + encoded_latitude = gps_packet[:4] + encoded_longitude = gps_packet[4:8] + + (y1, y2, y3, y4) = struct.unpack("<bbbb", encoded_latitude) + + decodedLatitude = 90.0 - ((((y1-33) * pow(91,3)) + ((y2-33) * pow(91,2)) + ((y3-33) * 91) + y4-33) / 380926.0); + + (x1, x2, x3, x4) = struct.unpack("<bbbb", encoded_longitude) + + decodedLongitude = -180.0 + ((((x1-33) * pow(91,3)) + ((x2-33) * pow(91,2)) + ((x3-33) * 91) + x4-33) / 190463.0); + return f"{decodedLatitude}N / {decodedLongitude}E" + +print(decodeEncodedGPS(EXAMPLE_MSG)) diff --git a/python/igate.py b/python/igate.py index 91edbcc..7c2e131 100755 --- a/python/igate.py +++ b/python/igate.py @@ -26,6 +26,9 @@ APRS_IS_SERVER = "france.aprs2.net" APRS_IS_PORT = 8080 CALLSIGN = "HB9EGM-10" +# See https://github.com/aprsorg/aprs-deviceid/blob/main/ALLOCATING.md +APRS_DEVICEID = "APZEGM" + # 46°23.07' N 6°13.28' LATITUDE = "4623.07N" LONGITUDE = "00613.28E" @@ -132,7 +135,7 @@ try: if last_beacon_time + 1800 < now: last_beacon_time = now - packet = f"{CALLSIGN}>APLRG1,qAC:={LATITUDE}L{LONGITUDE}&{COMMENT}" + packet = f"{CALLSIGN}>{APRS_DEVICEID},qAC:={LATITUDE}L{LONGITUDE}&{COMMENT}" try: send_frame_to_aprs_is(packet.encode()) except Exception as ex: |