search

sandeepmistry / arduino-LoRa

An Arduino library for sending and receiving data using LoRa radios.
MIT License
1.65k stars 630 forks source link

Compatibility with RAK831 SX1257 #219

Open janbbeck opened 5 years ago

janbbeck commented 5 years ago

First of all, thanks for this library. I used it to get a number of boards talking to one another including the Adafruit 32u4, HELTEC esp32 based boards and even an STM32LRWAN1. They all work great.

However, I cannot get them to talk to a RAK831 concentrator based on the SX1257. The util_tx_test claims to be sending out the packets sucessfully, but the Arduino boards do not see them The other way, the util_pkt_logger does not see the packets when sent by the Arduino.

I don't plan to do LoraWAN, I want to grab the packets from the concentrator and then do custom processing on the computer.

Are the two platforms compatible?

Thanks for taking the time to read this.

Update: The RAK831 I have is specified for 915 Mhz. But when configuring everything for 868 Mhz, util_pkt_logger sees an occasional partial packet from the Arduino. It always as a BAD_CRC and the payload is mangled. I.e. when sending "Hello", I might see the H and o, but the rest would be unprintable characters. The units are on the same desk. Arduinos on the same desk communicate with no problem. I was thinking that maybe the signal was too strong, but moving the Arduino out of the room suppresses reception entirely. Do I need to configure the Arduino Lora in some special way? Any ideas at all would be appreciated.

Update2: I obtained a SDR-RTL and it's pretty clear that the RAK831 does not actually send any RF at 868 Mhz, though it does send at 915. So the filter catches 868Mhz. Still, my arduinos at 915 Mhz cannot see it or vice versa

sabas1080 commented 5 years ago

util_pkt_logger or lora gateway tools only work for loraWAN according to memory, for you experiment should try to directly handle the register of the RAK831 and use only lora

janbbeck commented 5 years ago

util_pkt_logger or lora gateway tools only work for loraWAN according to memory, for you experiment should try to directly handle the register of the RAK831 and use only lora

Thank you for taking the time to reply. Using it, I was able to figure it out, though FYI you were incorrect.

I did use a LoraWAN implementation for arduino, and immediately the RAK831 saw the packets. But then I noticed that it was using 904.5 MHz instead of the 915 we put into the sandeep lora code. (Makes a lot of sense in retrospect) Changing using 904.5 Mhz with the sandeep library causes the RAK831 util_pkt_logger to see the packets. Thanks again.