Notes

These notes should work for both WeMos Mini boards as well as for the following simple ESP12F circuitry suitable even for breadboard:

However in the case of WeMos board there is no need to manually change RESET and GPIO0 levels and to use before and after parameters in esptool. All the switching between running mode and programming mode will be done done using DTR/RTS of integrated USB-to-Serial chip.

Using Minicom with original AI Thinker firmware

Switch the board to running mode: set high level on GPIO0 pin
Connect Minicom to device serial port with 115200 8N1 settings
Enable carriage return using CTRL-A U control sequence
Reset device: toggle low level on RST pin

Ai-Thinker Technology Co. Ltd.
ready

Run AT commands pressing Enter and then CTRL-J after each command:

AT
OK

AT+GMR
AT version:0.60.0.0(Jan 29 2016 15:10:17)
SDK version:1.5.2(7eee54f4)
Ai-Thinker Technology Co. Ltd.
May  5 2016 17:30:30
OK

Check device settings in programming mode

Switch the board to programming mode: set low level on GPIO0 pin
Reset the board: toggle low level on RST pin
Run esptool to get chip parameters: reset chip between each command

$ sudo esptool.py --port /dev/ttyUSB0 --before no_reset_no_sync --after no_reset chip_id
esptool.py v2.6
Serial port /dev/ttyUSB0
Connecting...
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
MAC: 60:01:94:02:a9:f9
Uploading stub...
Running stub...
Stub running...
Chip ID: 0x0002a9f9
Staying in bootloader.

$ sudo esptool.py --port /dev/ttyUSB0 --before no_reset_no_sync --after no_reset read_mac
esptool.py v2.6
Serial port /dev/ttyUSB0
Connecting...
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
MAC: 60:01:94:02:a9:f9
Uploading stub...
Running stub...
Stub running...
MAC: 60:01:94:02:a9:f9
Staying in bootloader.

Brief NodeMCU HOWTO

NodeMCU project provides an excellent documentation, so no need to go into much details here. In brief, do the following steps to build and flash firmware image to WeMos D1 mini board:

Get firmware source code

$ git clone https://github.com/nodemcu/nodemcu-firmware.git

Customize NodeMCU firmware image Edit app/include/user_modules.h
Build firmware Build NodeMCU firmware:

$ make

Flash firmware Switch device into programming mode and NodeMCU firmware

$ sudo ./tools/toolchains/esptool.py --port /dev/ttyUSB0 write_flash -fm dio -fs 32m 0x00000 bin/0x00000.bin 0x10000 bin/0x10000.bin

How to copy Lua scripts to device spiffs

Using luatool:

$ sudo luatool.py --port /dev/ttyUSB0 --src test.lua --dest test.lua -b 115200

Using nodemcu-tool:

$ sudo nodemcu-tool upload init.lua
$ sudo nodemcu-tool upload test.lua -n main.lua

How to create and flash spiffs image

Create image content list

$ cat script.img
import init.lua init.lua
import test.lua test.lua
import nrf24.lua nrf24.lua

Generate spiffs image

$ spiffsimg -f fs.img -S ${FLASH_SIZE} -U ${SPIFFS_SIZE} -r script.img

Flash spiffs image to device

$ sudo /home/matsi/bin/esptool.py --port /dev/ttyUSB0 write_flash -fm dio -fs ${FLASH_SIZE} ${SPIFFS_OFFSET} fs.img

geomatsi / nodemcu-tests