In the past month I designed different version of a PCB, all based on the original MiniPill LoRa node.
Version 2.0 Smaller and Longer to fit enclosure
After getting my HAM Radio license in March this year, I wanted to improve the sending capability of my MiniPill LoRa v1.x. So I designed a new PC with other to dimensions (18x x 45 mm) so it would fit into some projects.
I used a IPEX4 connector, a little by mistake, I wanted a IPEX1 connector, but did not choose the right component in my drawing program. After all this was no problem at all. Hot Air soldering does the trick and I have a good and very small connector on my board.
I will show you the results.
I’ve done a first test with a 2.5 dB antenna on the SMI connector and at long distance it was indeed a difference of 2 dB in comparison with the line antenna. I will have to do some more tests.
This is just a 2.0 version, maybe I will remove the BME280 connector. And for sure I will add markers to the connectors. I did not put the pinnames on the silk-screen. That was a huge mistake :-(.
The size of this board is: 18 mm x 45.5 mm (the MiniPill LoRa original: 23 mm x 33 mm)
Version 3.0 Same Form Factor as ATtiny Node
Due to unable to receive downlink messages/commands The Things Network does keep sending downlink messages and congesting the radio band. I had a practical solution, but due to updates on The Things Network it does not work anymore as good as I hoped for. To replace the ATtiny84 based processor nodes I made a STM32L051 based node with the same formfactor
The size of this board is 20.5 mm x 45.5 mm
I have made this MiniPill v3.0 project available on https://oshwlab.com/leo/stm32-minipill-lora-v3-0
Version 2.5 a round one for fun
Just for fun and of course as challenge I made a round version for a CR2032 battery. I succeed and even a CR2450 can be used. The only challenge now is to update or find code that uses minimal power. The OTAA code I use at this moment (LMIC like) does use too much energy between uplink sending en downlink listening. Especially with the 5 seconds RX1 window.
The size of this board is 28 mm round