ESP8266 Community Forum

- Tue Nov 29, 2016 8:32 pm #58867 I designed an environmental sensor with an ESP8285 chip. After having assembled it, I wanted to test it with AT commands. I received some sort of signal, but with frame error after pushing the reset button. But my AT commands were unanswered. I checked the initial TX signal with an oscilloscope. It looked ok, but had a baud rate around 7519. What I checked:

• The crystal: It provided a 26Mhz sine wave (as intended)
• The 12k resistor: It had less than 1% value error, and I measure 0.6V on it.

Oscilloscope photo: http://imgbox.com/KsjlgkGK
Project topic: http://www.esp8266.com/viewtopic.php?f=11&t=12147&p=57182

- Wed Nov 30, 2016 2:22 am #58878 The esp8266 bootloader always sends some info at startup after power-up/reset with baud rate 74880.

- Wed Nov 30, 2016 5:38 am #58887 Why does the esp8266 boot up with a baud rate of 74880? See this :-http://www.esp8266.com/viewtopic.php?f=160&t=12635

- Wed Nov 30, 2016 7:12 am #58892 With that baud rate the startup message is (when I press the reset):

Code: Select all ets Jan  8 2013,rst cause:2, boot mode:(3,7)

ets_main.c


But still no response to AT commands.

Update: But programming and flashing works fine. I guess there was no AT firmware preinstalled.