LoRa HM-TRLR-S 100mW 433MHz Setup

Hi there,
I need some help setting up my recently bought lora radios. I wired them up to my dropix flight controller running apm 3.3.3. TX/RX connection is crossed over as with the 3dr v1 radios.
I can open the port with 9600 baudrate, the small tx / rx leds are flickering, but i can’t get a Mavlink connection to the missionplaner. I tried some modifications with the HM_TRLR tool, without succes.
Can you please give me some advice how to configure the radios to get them working.

Many thanks in advance and best regards,



Trying to get MAVlink packets through Lora might not be the best choice"as-is". First limitation, with Lora communication you cannot send packets bigger than 127 bits (in the best scenario case) and some MAVlink packets are bigger than this limitation. Second limitation, Lora is a kind of slow modulation, so MAVlink rate creates constant overflows. Technically it can work but you would need to cut your packets “smartly” before feeding the transmission system. If you can’t get it to work, switch to FSK modulation. The baudrate has to be 57600 in all cases.

Hi, same here. I have the LoRa HM-TRLR-S. Tried to configure it to GSK, 57600 baud (both modules). Configured pixhawk telem 1 port with same speed and MAV protocol. No communication.
Tried PX4 1.8.0 + QGroundControl (this setup, both modules’ leds blink once a second, one green other red, no comms)
Arducopter 3.6dev + MP = no comms, no led

Same here, Is there any success so far? What is the useable configuration?

Dear Drotek,

Could you please clarify if LORA-HM-TRLR-S does or does not work with Mavlink?