Reading UID of mifare cards using i2c protocol communication with pn532 modules.
Unofficial Development Kit for Espressif ESP826 , http://www.esp8266.com/viewtopic.php?t=820
I2C clock stretching fixed by pasko-zh: https://github.com/pasko-zh/brzo_i2c
Tested with Adafruit Feather HUZZAH with ESP8266 WiFi, url : https://www.adafruit.com/product/2821 pn532 module v3 :https://dangerousthings.com/wp-content/uploads/PN532_Manual_V3-1.pdf and https://www.adafruit.com/product/789
Programming ESP8266 with FLASH_DOWNLOAD_TOOLS_Vx.x.x ( Newest Version) https://espressif.com/en/support/download/other-tools