Copyright (C) Bruce MacKinnon, 2025. Contact info at bottom of the page for comments/corrections.

This module is manufactured by REYAX Technology Corporation, LTD, based in Taiwan. The Vendor datasheet is here.

The module is based on the Semtech LLCC68 radio/modem chip.

The module is packaged as a daughter-card with castellated pads for SMD mounting on a PCB.

Notes vs SX1276

  • Only supports 125, 250, and 500 kHz bandwidths.
  • Only supports SF5-9 on 125 kHz, SF5-10 on 250 kHz, and SF5-11 on 500 kHZ.
  • LLCC68 has added a BUSY pin. When BUSY is low it indicates that the internal state machine is in the idle mode and that the radio is ready to accept a command from the host.

Driver Notes

  • At power-up or after reset there is a period during which the chip is busy (i.e. BUSY high). Wait for this condition to clear before sending commands.
  • Calibration is one of the things that is happening during this initial period.
  • DIO1 is the generic IRQ line. Any of the interrupts can be mapped to this line.
  • FS mode is used for test purposes of the PLL.

KiCad Notes

I’ve created a KiCad footprint for this module:

Module

Here’s the footprint w/ dimensions:

Module