I have esp8266-01. To update firmware. I use this connection.
usb-ttl && esp8266-01
TXD->RXD
RXD->TXD
VCC->CH_PD
VCC->VCC
GND->GPI0
GND->GND
And after that when i remove GPI0. I can use command AT. But with the same connection after put GPI0 back with GND. I am able to send programming code in esp. After that even if i remove GPI0 i cannot use AT command anymore. Please help?
But after update firmware i am getting this message again and again.
ets Jan 8 2013,rst cause:4, boot mode:(3,0)
wdt reset
load 0x40100000, len 1396, room 16
tail 4
chksum 0x89
load 0x3ffe8000, len 776, room 4
tail 4
chksum 0xe8
load 0x3ffe8308, len 540, room 4
tail 8
chksum 0xc0
csum 0xc0
2nd boot version : 1.4(b1)
SPI Speed : 40MHz
SPI Mode : QIO
SPI Flash Size & Map: 8Mbit(512KB+512KB)
jump to run user1 @ 1000
{l�ƒ{l„Ÿâ„c,þ
ready
WIFI DISCONNECT
The ESP8266 is a little computer, what it does depends on the program it is running.
From the factory there appears to be a fairly permanent program (likely in ROM on the ESP8266 itself) which functions as a bootloader that can accept downloads of custom programs to the companion flash chip. You can select operation of this bootloader program via the level of one of the pins at boot, while the opposite setting runs whatever custom program is in the companion flash.
One possible custom program is one which interprets AT commands. Often something of this sort is already on the companion flash chip when you buy an ESP8266 on a board. However, if you erase it or replace it with something else that does not interpret AT commands, then that capability is lost.
You should be able to obtain an AT command interpreter program to re-load if you want to return to having that capability.