sybip

Frequency error and calibration in GTM-LAB radios

A disorderly collection of ideas, concepts and design decisions.

In theory

In simple terms, a crystal oscillator's frequency error is the difference between the nominal frequency as marked on the box, and the actual frequency that the oscillator delivers.

sybip

//
// GTM User Device Firmware
// ------------------------
// Emulates a goTenna Mesh device, network-side as well as client-side, 
//  sufficiently realistic to function as a drop-in substitute for the
//  genuine GTM with most existing GTM apps (goTenna, ATAK, txTenna etc)
//
// This GTM LAB example code uses gtmRadio, gtmBLE and gtmAPI from:
//
// GTM LAB - goTenna Mesh protocol playground

sybip

SYS.UPTIME: 1209356.844s
RX PACKETS:
- SYNC: 447126
- DATA: 887328
-  ACK: 323
- TIME: 0
TX PACKETS:
- SYNC: 51
- DATA: 86
-  ACK: 10

sybip

#!/usr/bin/env python
"""
goTenna mesh message logger, using USB connected gtm-lab receiver
    more info at: https://github.com/sybip/gtm-lab
"""
import serial
import sys
from time import gmtime, strftime
from binascii import unhexlify

sybip

"""
A placeholder for the official goTenna SDK, trying to implement just the
  BARE minimum functionality needed to trick the sample app into not
  throwing any fatal errors.
Obviously there's no actual goTenna action going on; only an empty shell
  that imitates the "real thing", unsuccessfully so far (2021-03-14)

TODO: actually read the SDK spec, it's free! :)
"""

sybip

#!/usr/bin/python
# Simple demo of the pyGT library - send a shout message via goTenna Mesh

import sys
# from https://github.com/sybip/pyGT
import gtdevice
from compatGTA import gtMakeGTABlobMsg
from gtapiobj import gtMakeAPIMsg

# One line of help

sybip

#!/usr/bin/env python
"""
goTenna Mesh metadata logger, using USB connected gtm-lab receiver
    more info at: https://github.com/sybip/gtm-lab
"""
import serial
import sys
from time import gmtime, strftime
from binascii import unhexlify

sybip

#!/usr/bin/python
# Simple demo of the pyGT library - send a shout message via goTenna Mesh

import sys
import time
from struct import pack
# from https://github.com/sybip/pyGT
import gtdevice
from pycrc16 import crc