ESP8266 Community Forum

- Wed Jun 29, 2016 7:52 am #49952 I've connected the module:
ESP-12---------USB-TTL (CP2120)
VCC ----> 3.3V Power supply .
GND ----> Ground of power supply
CH_PD ----> HIGH (3.3V)
GPIO2 ----> HIGH (3.3V)
GPIO15 ----> LOW (GND)
GPIO0 ----> HIGH or Floating for AT Mode (3.3V) [ if you want to flash completely different firmware then you must connect it to ground ]

When i connect USB-TTL to a terminal the module sends me constantly

wdt reset
load 0x40100000, len 25052, room 16
tail 12
chksum 0x0b
ho 0 tail 12 room 4
load 0x3ffe8000, len 3312, room 12
tail 4
chksum 0x53
load 0x3ffe8cf0, len 6576, room 4
tail 12
chksum 0x0d
csum 0x0d
Fatal exception (0):
epc1=0x401060f1, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000

ets Jan 8 2013,rst cause:4, boot mode:(3,7)

What could be a problem?

- Wed Jun 29, 2016 10:42 am #49958 Hi, GPIO 0 & 2 need to be pulled up with a 10K resistor.
Reset also needs to be HIGH idealy through a 10K resistor as this makes it easier to ground when flashing.
Its very possable that the CP2120 cannot supply the current needed by the ESP, try 2x 1.5V batteries and just don't use the V+ from the CP2120. See how you go with that for a start.

- Wed Jun 29, 2016 1:40 pm #49963 Thank you. I'll try more robust converter.