Coded a better payload transmit test routine for OOK

Started coding up new burst transmission scheme

Started to write another test case to blurt out OOK energenie messages. ...

This is only a test case.
But it has highlighted a whole load of discrepancies in the original C
code to do with payload length calculation, and the 'magic' zero byte
at the start of the buffer for stuffing the SPI register address in.

Tracked down the 'long sync bit' problem. ...

It's due to the HRF always preceeding each packed with an extra 01 at start.
Existing driver code sends 'chips' to prove this.
Looking like a preamble of zeros will be required to make this a non issue,
and then generate the real 80000000 preamble as part of the payload.

Got the radio chirping again after a long period of not working at all

hrfm69_test.c now sending a tone. ...

Discovered that 1/5 times it sticks waiting for TXREADY.
This might suggest an unresolved sequencing error in startup.

spi_test.c can now read back the version number of the HRF69 chip

Simple GPIO tester works on Raspberry Pi (flashes LEDs on radio)

Built a simple C test harness to start testing the radio with

Experiments on Arduino with larger register writes and FIFO write ...

Getting some corruption on the Arduino RAM buffers.
Logic analyser traces show that the tables are getting corrupted
and the wrong data is being written to the radio registers.

Managed to write/read the mode register from real RFM69 with Arduino

Reset, select, write working on Arduino

SPI being driven on Arduino

Got simple 5 pin interface with GPIO working on Arduino Pro Micro

Preparations for wiring up to Arduino

A 'go for broke' OOK transmitter added to hrf69_test

Implemented most of hrf69.c write and read functions

HRF_write_reg written

Factored out all stdio from all testers and code

Mock read and write test working for radio register

Proved that we can read a register back from simulation

First pass at writing a test in hrf69_test.c

Marked the interface queries in HRF69.h

First attempt at specing out implementation of HRF69 based on python

spi_test working on Mac

Refactored delay into a platform module

gpio_sim working on Mac

Wrote GPIO simulator in a mostly platform independent way.

Framework in place for Arduino GPIO and simulated GPIO

GPIO is now tagged as RPi specific in build process