gitdode/librfm69
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
Static avr-libc library providing basic support for RFM69 radio modules
33 commits 1 branch 0 tags 1.2 MiB
  • C 59.4%
  • Makefile 34.3%
  • Shell 6.3%
Find a file
Exact
gitdode c4025abc22 Adjust link
2026-04-07 21:13:44 +02:00
nbproject Incorporate changes from librfm95 (#3) 2025-04-13 16:15:29 +02:00
sheet Add data sheet 2025-04-19 21:48:05 +02:00
.gitignore Fix build and Makefile 2025-03-24 18:53:07 +01:00
CODE_OF_CONDUCT.md Initial commit 2025-03-24 00:58:44 +01:00
librfm69.c Return actual size of payload received by receiver 2025-11-17 19:43:38 +01:00
librfm69.h Some recommendations from Semtech AN1200.24 (#8) 2025-05-05 22:04:53 +02:00
LICENSE Initial commit 2025-03-24 00:58:44 +01:00
Makefile MCU = avrxmega2 2025-11-13 19:13:36 +01:00
README.md Adjust link 2026-04-07 21:13:44 +02:00
utils.h Initial commit 2025-03-24 00:58:44 +01:00

README.md

librfm69

About

Static avr-libc library providing basic support for RFM69 radio modules.

This is work in progress. Currently available is:

  • Transmit a packet
  • Blocking receive a single packet with timeout
  • Async'ly receive a packet (MCU sleeps or does something else until reception)

Usage

  1. Include librfm69.h and librfm69.a in the project
  2. Implement the _rfm* functions in librfm69.h in the application (this is to make the library device and CPU frequency independent)
  3. Route interrupts occurring on DIO0 and DIO4 to rfmIrq()

Range

There is a range test with an RFM95 in FSK mode at librfm95.

Susceptibility to Temperature Changes

With the default frequency deviation of 5 kHz and receiver bandwidth of 10.4 kHz, packet transmission is very unreliable and fails completely for me when the temperature of the transmitter is below 10°C and above 40°C, while the receiver temperature is at 20°C. The receiver does not seem to be prone to temperature changes.
Increasing frequency deviation to 10 kHz and receiver bandwidth to 20.8 kHz, temperature susceptibility is eliminated; when testing with transmitter temperature from -20°C to 50°C, packet transmission is perfectly reliable.

Frequency Deviation = 10.4 kHz (transmitter)
RegFdevMsb = 0x00
RegFdevLsb = 0xa4

Receiver Bandwidth = 20.8 kHz
RegRxBw = 0x54

The issue can probably also be solved with automatic frequency correction (AFC).