ESP8266 does not respond after changing baud rate to 9600

Question

I have ESP8266 WiFi module and Arduino Mega Board connected. I use external 5 to 3.3 V regulator to power up the module. Common (-ve) line on the external power source and Arduino Mega GND is connected. Then I used 1K and 2K voltage divider for WiFi module RX and TX use as same. I am sure my circuit is well works.

Then I connect RX0-RX and TX0-TX. Then i put CH-PD to 3.3v

Then I opened the Arduino IDE and upload the Blink sketch. Done.. Then I opened Serial Monitor and set baud rate to 115200. Then power up the module. It gave me a lots of garbage values and ready. Fine.

Then I downloaded the FLASH_DOWNLOAD_TOOLS_v0.9.5. configure the 0x0000, 0x1000 and 0x7c000

1. SPI speed = 40MHZ
2. SPI mode = QIO
3. FLASH size = 4Mbit
4. 0x1000 = ai-thinker-0.9.5.2-9600.bin

Then O power off the module and connect GPIO0 to ground and again power on.

Then push start button. Then it downloaded to the chip. It worked. Done. Success fully uploaded. Then I again disconnected the GPIO0 and power on. Then I put AT and it results OK.

AT+GMR gives version 0.9.5 updated.done.

The problem was the module was responded for 115200 baud rate, not 9600. Then I:

AT+IPR=9600

it gives me nothing.

Now I can't communicate with it at either 115200 or 9600 baud. No respond whatever baud rate I put. Sometimes I am having same garbage values.

Answer 1

This is a common issue. Using the AT+IPR command seems to brick the module. Try to re-flash your module, like you did the first time. If it works, use this command: AT+UART_DEF=9600,8,1,0,0 instead to change the baud rate.