$ esptool.py chip_id
esptool.py v2.5.1
Found 1 serial ports
Serial port /dev/ttyUSB0
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
MAC: 84:f3:eb:0b:dd:53
$ esptool.py chip_id
esptool.py v2.5.1
Found 1 serial ports
Serial port /dev/ttyUSB0
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
MAC: 84:f3:eb:0b:dd:53