Sonoff S31

Stock firmware boot messages

 ets Jan  8 2013,rst cause:1, boot mode:(3,7)

load 0x40100000, len 2592, room 16 
tail 0
chksum 0xf3
load 0x3ffe8000, len 764, room 8 
tail 4
chksum 0x92
load 0x3ffe82fc, len 676, room 4 
tail 0
chksum 0x22
csum 0x22

2nd boot version : 1.7(5d6f877)
SPI Speed : 40MHz
SPI Mode : QIO
SPI Flash Size & Map: 32Mbit(512KB+512KB)
jump to run user1 @ 1000

rf cal sector: 1019
freq trace enable 0
rf[112]

Flash Info via esptool

> ./esptool.py --port /dev/ttyUSB0 flash_id

Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: c8:c9:a3:xx:xx:xx
Uploading stub...
Running stub...
Stub running...
Manufacturer: c8
Device: 4016
Detected flash size: 4MB