20/100mW GFSK Transceiver With Scrambler, AES-Encryption And SPI Interface Based On Semtech SX1231

The RFM69 is the successor of the popular RFM22 which in turn was the successor of the RFM12.

This transceiver module is based on the RF69 transceiver chip that can be programmed via SPI interface. This chip in turn is based on Semtech SX1231 (20mW standard version) and Semtech SX1231H (100mW H version).

On the RF69 transceiver chip, look at the 4-digit number below RF69 to find out the production date. The first two numbers are the year, the second two numbers represent the week of year.

The board is available in four frequency versions: 315MHz, 433MHz, 868MHz, and 915MHz.

Board Variations

This board is available in four variants:

Model TX Power Pins Size Remarks
RFM69(W) 13dBm/20mW 16 19.7x16mm end of life
RFM69C(W) 13dBm/20mW 14 16x16mm active, pin-compatible to older model RFM12B
RFM69H(W) 20dBm/100mW 16 19.7x16mm end of life
RFM69HC(W) 20dBm/100mW 14 pin-compatible to older model RFM12B  

The actual version is printed on the back side:

Technical Data

Item Value
Voltage 1.8-3.6V
Frequency 387-464MHz
Output Power 10dBm / 10mW
Modulation FSK, GFSK, MSK, GMSK and OOK
Standby Current 0.1uA
TX Operating Current 45mA at 13dBa/20mW
RX Operating Current 16mA
Transmission Rate up to 300kbps (FSK)
Receiver Sensitivity -115dBm
Extras RSSI signal detection, hardware CRC, carrier sense, 64-byte RX and TX buffer
Interface SPI

Special Features

The transceiver chip comes with a number of useful functionalities built into its hardware:

  • Manchester Encoder/Decoder
  • Packetengine for synchronous word, CRC, Scrambling, AES-128 encryption
  • 66bit FIFO buffer
  • built-in temperature sensor


All pins are labeled on the back side:

Pin Description
GND negative voltage
ANA Antenna
GND negative voltage
SCK SPI-Interface, Clock
MISO SPI-Interface, Data Out
MOSI SPI-Interface, Data In
NSS SPI-Interface, Chip Select
NC not connected
3.3V 1.8-3.6V
DIO5 ModeReady ClkOut, Data
DIO3 Fifo Full, PLL Lock, RSSI, SyncAddress, TXReady
DIO2 FifoNotEmpty, Automode, Data
DIO1 FifoLevel, FifoFull, FifoNotEmpty, PLL Lock, Timeout
DIO0 PLL Lock, CrcOk, Payload Ready, SyncAddress, RSSI, PacketSent, TxReady


This board uses the SPI interface to communicate with a microcontroller.

Software Libraries


Data Sheet

RF69 Transceiver Chip
Semtech SX1231


Please do leave comments below. I am using utteran.ce, an open-source and ad-free light-weight commenting system.

Here is how your comments are stored

Whenever you leave a comment, a new github issue is created on your behalf.

  • All comments become trackable issues in the Github Issues section, and I (and you) can follow up on them.

  • There is no third-party provider, no disrupting ads, and everything remains transparent inside github.

Github Users Yes, Spammers No

To keep spammers out and comments attributable, all you do is log in using your (free) github account and grant utteranc.es the permission to submit issues on your behalf.

If you don’t have a github account yet, go get yourself one - it’s free and simple.

If for any reason you do not feel comfortable with letting the commenting system submit issues for you, then visit Github Issues directly, i.e. by clicking the red button Submit Issue at the bottom of each page, and submit your issue manually. You control everything.


For chit-chat and quick questions, feel free to visit and participate in Discussions. They work much like classic forums or bulletin boards. Just keep in mind: your valued input isn’t equally well trackable there.

  Show on Github    Submit Issue

(content created Apr 18, 2024)