Connect Ra-01 module base on LoRaTM SX127x chip to ESP8266/ESP32 under MicroPython

Notes

1. This is experimental example, not software product ready for use
2. This this free and open source software
3. Author: Alex Zorg azorg(at)mail.ru
4. Licenced by GPLv3
5. Some sources based on:

• https://github.com/Wei1234c/SX127x_driver_for_MicroPython_on_ESP8266
• https://wei1234c.blogspot.tw/2017/08/sx127x-lora-transceiver-driver-for.html

Download Micropython firmware

Go to:

1. "Getting started with MicroPython on the ESP8266" http://docs.micropython.org/en/latest/esp8266/esp8266/tutorial/intro.html

2. "Firmware for ESP8266/ESP32 boards" http://micropython.org/download

Install esptool.py - ESP8266 & ESP32 ROM Bootloader Utility

$ sudo apt-get install python-pip
$ sudo pip install esptool

OR

$ sudo apt-get install python-serial
$ sudo apt-get install python-ecdsa ecdsautils
$ sudo apt-get install python-slowaes
$ git clone https://github.com/espressif/esptool.git
$ cd esptool
$ sudo python setup.py install

Flash firmware on ESP8266/ESP32 board

ESP8266:

$ esptool.py --port /dev/ttyUSB0 erase_flash
$ esptool.py --port /dev/ttyUSB0 --baud 115200 write_flash --flash_size=detect 0 firmware.bin

ESP32:

$ esptool.py --chip esp32 --port /dev/ttyUSB0 erase_flash
$ esptool.py --chip esp32 --port /dev/ttyUSB0 write_flash -z 0x1000 firmware.bin

Connect LoRa module to ESP8266/ESP32

GPIO	DOIT ESP32	NodeMCU v3	Signal	SX1278 (color)
0	-	D3
2	D2	D4	Blue LED
4	D4	D2	IRQ	DIO0 (yellow)
5	D5	D1	HARD RESET	RESET (magenta)
9	-	S2?
10	-	S3/SK?
12	D12	D6	MISO	MISO (blue)
13	D13	D7	MOSI	MOSI (green)
14	D14	D5	SCK	SCK (white)
15	D15	D8	CS	NSS (grey)
16	RX2	D0	DATA*	DIO2* (brown)
-	-	-	DCLK**	DIO1** (orange)
	3V3	3V	3.3V	3.3V (red)
	GND	G	GND	GND (black)

Note (*): DIO2(DATA) is optional and may used in continuous FSK/OOK mode

Note (**): DIO1(DCLK) unused

Build mpy-cross

$ sudo apt-get install build-essential libreadline-dev libffi-dev git

$ git clone --recurse-submodules https://github.com/micropython/micropython.git

$ cd ./micropython/ports/unix
$ make axtls
$ make
$ sudo cp ./micropython /usr/local/bin

$ cd ../../mpy-cross
$ make
$ sudo cp ./mpy-cross /usr/local/bin

Install ampy - Utility to interact with a MicroPython board over a serial connection

$ sudo pip install adafruit-ampy

OR

$ sudo apt-get install python-click
$ git clone https://github.com/adafruit/ampy.git
$ cd ampy
$ sudo python setup.py install

Read and edit "main.py" and "sx127x.py", compile "sx127x.py"

$ vim sx127x.py
$ vim main.py
$ mpy-cross -O3 sx127x.py

Load python examples to ESP module

$ ampy --port /dev/ttyUSB0 put sx127x.mpy
$ ampy --port /dev/ttyUSB0 put main.py

Run terminal (minicom, picocom or screen)

$ minicom -D /dev/ttyUSB0 -b 115200

$ picocom /dev/ttyUSB0 -b 115200

$ screen /dev/ttyUSB0 115200