#115 Making A DIY LoRa Module
When taking a closer look at the DIY aspect of lora I wanted to test LoRa peer to peer.. E.G multiple peers to one peer (NOT LoRa WAN) I noticed that the actual radio PCB is difficult to use when going the traditional through hole way… adapter boards do exist but are few and far between at least in SA. you can make your own for manufacture but then rather create your entire product PCB for manufacture.
Even with this drawback I was able to source old adapters for one of the very firs modules the: RFM95W. In South Africa we are mostly using 868Mhz although 433Mhz modules are around I don’t see them being super common in terms of LoRa modules.
The modules I used have a footprint for adding a female SMA connecter for easy antenna connecting.
Parts used:
- 2x RFM95W 868Mhz LoRa module transceiver
- 2x 3.3v active buzzer
- 2x 1 pole dip switch
- 2x TP4056 module with protection ICs
- 2x ATtiny404 MCU
- 2x NCV8163 3.3V LDO
- 2x SSD1306 128×32 OLED
- 2x 2pin 2.5mm JST battery connector
- 2x Headers and jumpers
- 2x 13400 3.7V 550mAh
- 2x 10k resistors
- 2x 220R resistors
- 2x SOIC to DIP adapter PCB
- 2x BC547 transistors
- Some 0.9mm tin plated copper wire
- Some 0.255mm PVC insulated wire
After checking the PCB I commenced with testing the devices. Unfortunately the test area has largely mountains terrain
the signal works really well and penetrates better through foliage on the mountains terrain but once there is a full on mountain in the way the signal stops. so in this retrospect the devices are better then a radio which was quite interesting but makes sense because data is being sent and uses less bandwidth then interpreting voice audio. Also the error checking for LoRa helps a lot.
Some more pros for the LoRa is that its a transceiver out of the box with RSSI functions included. Also for increased range and/or quality the spreading factor and signal bandwidth can be adjusted.
Although there’s many pros regarding LoRa I still tend to use simple 433.92 RF modules without issue at least in my situation with rural areas under about 3KM at and given point.
So it really becomes more of a cost factor than anything else. Although I’m happy selling a custom LoRa product for compatibility with LoRa WAN or some other requirement with a similar principal. Plain old generic RF is still cool in my book.
