dk-w8266-lua

Self-contained NodeMCU-firmware Lua example for Deek-Robot 0.91" kit (here on AliExpress, prod to have your link added), a.k.a. Heltec Wifi Kit 8.

Build requirements

Build the firmware with (at least) these modules:

bit file gpio i2c node tmr u8g2 uart wifi

Also ensure you choose ssd1306_i2c_128x32_univision as the I²C display in the build UI's dropdown (for this example, it is irrelevant what you choose for the SPI dropdown, and the default font list of font_6x10_tf,font_unifont_t_symbols will suffice).

Flash said firmware using e.g. esptool.py:

$ ./esptool.py --port /dev/ttyUSB0 write_flash -fm qio 0x00000  nodemcu-master-*-modules-*.bin
esptool.py v2.2
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266EX
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Auto-detected Flash size: 4MB
Flash params set to 0x0040
Compressed 475136 bytes to 309820...
Wrote 475136 bytes (309820 compressed) at 0x00000000 in 27.3 seconds (effective 139.2 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting...

Usage

(Assuming nodemcu-tool is in $PATH.)

$ make upload restart console
nodemcu-tool upload init.lua
[NodeMCU-Tool]~ Connected 
[device]      ~ Arch: esp8266 | Version: 3.0.0 | ChipID: 0x4eafa6 | FlashID: 0x1640ef 
[NodeMCU-Tool]~ Uploading "init.lua" >> "init.lua"... 
[connector]   ~ Transfer-Mode: hex 
[NodeMCU-Tool]~ File Transfer complete! 
[NodeMCU-Tool]~ disconnecting 
nodemcu-tool reset
[device]      ~ Hard-Reset executed (100ms) 
[NodeMCU-Tool]~ disconnecting 
nodemcu-tool terminal
[terminal]    ~ Starting Terminal Mode - press ctrl+c to exit 
--- Starting Graphics Test ---
>

Resources

Useful resource.

Totally ripped off from graphics_test.lua

Also useful