MQTT client build on esp8266 chip.

esp8266 can be connected to linux based computer via serial port with CuteCom. This is necessary for chips programming, debuging, topics reporting and list connected client names (CLID).

Uploading firmware to esp8266 chips are done via esptool.py script. Main system is LUA based interpreter from nodemcu.

At first – clear SPI memory with blank file.

python ./path/to/script/esptool.py -p /dev/ttyS0  write_flash 0x00000 /path/to/esp/firmware/blank512k.bin

Next – upload main firmware (scripts are done with nodemcu_integer_0.9.6-dev_20150406.bin).

python ./path/to/script/esptool.py -p /dev/ttyS0  write_flash 0x00000 /path/to/esp/firmware/nodemcu_integer_0.9.6-dev_20150406.bin

Raspberry Pi or NLU2 (with installed Mosquitto MQTT broker) and programmed esp8266 clients are connected to regular WiFi AP network. There are two flash MQTT clients and one switch button MQTT client. One of the flash clients can relase camera shutter too. Flash is sync to max 1/250s time (without TTL – no flash automatic!) There must be add delay between shutter relase and flash relase to expose 1/250s correctly in time.