Designing a breakout board for the ESP32 / RFM9X

Had turned the esp but not the pinheaders. Did this later and back to a two layer board. Will take some weeks for the esp32 to become available. Check / double check my layout and will order a couple to see if it works.

Any updates on this design? I have some ESP32s on reel to spare and RFM95 modules and would love the give it a spin and tinker with the LMIC ports which are emerging.


Hi Martijn,

This project has been on hold since release of the module got delayed and havent got the time to pick it up. So it’s on the backbench for some time to come.



‘half the board’

US $0.99 incl. shipping

Ah yes, that backbench… Been looking at Osh Park for some shared projects but no dice.

It would be nice to have some design with power (battery clip, usb, LDO), ESP32 footprint, RFM footprint and perhaps some meander and/or uFL for the LoRa antenna. Some GPIOs exposed. Breakout is nice, but when it’s an all-in-one I won’t be needing the breadboard.

I’m lacking the skills on KiCad, but I have some PCB design at work on the ESP32 without the LoRa part. I’ll ask the schematics designer if he’s willing to contribute to the community.

Which LMIC ports are emerging? Is anything working yet?

I guess the easiest is to get a LoPy which is essentially an ESP32 + Sx1276 and just use ESP-IDF directly.

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Completely missed this LoPy, but some E30 is not hitting the sweet spot for me by a long shot,

So I’m I able to work in C/C++ on the IDF and skipping Python as I can flash my own IDF code as we do now? As a development board this could be interesting.

I’m looking at with some interest, but could be we will be sponsoring a port throughout the summer as we are moving away from PIC to ESP32 with one particular solution we currently use on a B2B application.

Yes I meant for development, for deployment I’m considering their OEM version at €15.

The OEM would need a breakout board but it’s a lot simpler - also it’s been tested and pre-certified so the cost makes sense to me, it’s similar to other LoRa modules but does a lot more.

You can program it with ESP-IDF sure, no restrictions, works like any ESP32 module.

I’ll try to find some time to test that LMIC, thanks for linking,

This is indeed something interesting! I’ll order some right away. Thanks for this, best find of the day.

Hi All,

So I’ve been working with the WiPy and LoPy boards for some months now. I’ve done some LoRaWAN experiments in MicroPython which are nice. I also flashed the WiPy boards with my own pure C/C++ IDF projects which give me more flexibility running tasks and connectivity (I use AWS IoT a lot when running over WiFi).

I’m still looking for a pure ESP32 LMIC IDF port. Came across the Lua-RTOS-ESP32 project which has an IDF port at first glance.

But before diving in. Are we still short of an ESP32 IDF port of the LMIC stack?

if you’ve installed the ESP32 package in arduino, you just can take the tt-abp, with an RFM95 attached to it
tested with ESP32-DOIT , board: ESP32 Dev Module choosen

/* for ESP32
static const uint8_t SS    = 5;
static const uint8_t MOSI  = 23;
static const uint8_t MISO  = 19;
static const uint8_t SCK   = 18;
// Pin mapping
const lmic_pinmap lmic_pins = {
    .nss = 5,                              //
    .rxtx = LMIC_UNUSED_PIN,
    .rst = 13,                             // 
    .dio = {12, 14, 27},                   // {DIO0, DIO1, DIO2},   DIO2 could be eliminated

Trick is though I’m not running the Arduino port. I’m running C/C++ with FreeRTOS tasks to schedule work and using eventgroups to exchange state among them.

Are you talking about something like that ?

that fits onto Lolin32 with Lipo Mode ?


With RN2483 footprint as bonus ?


Nice. Still, I need to have the LMIC ported. I’ll drop a note at the Lua-RTOS-EPS32 if we could extract the module and have it as a separate git submodule in the project.

nice! availble for sales? Where? Thx!

any update on esp32 . or anyone use heltec lora board or ttgo lora board ? thx

You may be interested in that link I posted in the BARGAIN forum section.

ESP32 with SX1276 (868/915 MHz) and 0.96" OLED display now released.

Assembled, mounted, plugged onto Lolin32 tested, first TTN join this night :wink:
just a little error RST line of RFM95 connected to GPIO35 which is input only (sad) so you can’t reset RFM by software but do you really need it? If you really need it, quick fix add wire between between GPIO33 (unused) and GPIO35 and reset using GPIO33

I need to clean up and publish to github, in the meantime you can order them on, have fun
Reset fixed in V1.1 it’s now on GPIO25


Have a look here: BIG ESP32 / SX127x topic part 1