ESP8266 garbage values on Serial Monitor (espcomm_sync fail) | ESP8266 Wi-Fi Module | Forum

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ESP8266 garbage values on Serial Monitor (espcomm_sync fail)
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August 20, 2018
3:14 am
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puneet336
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August 20, 2018
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I have purchased Wi-Fi module from - https://www.amazon.in/REES52-Serial-Wireless-Transceiver-ESP8266/dp/B00O34AGSU/ref=sr_1_1?s=industrial&ie=UTF8&qid=1534744260&sr=1-1&keywords=Wi-Fi+Wireless+Transceiver+Module+for+IOT+ESP8266.

I had also purchased a 5v/1A DC power adapter to externally power the module. With the information at - https://iotbytes.wordpress.com/3-3v-power-supply-for-esp-8266/, Initially, i used pin #2(3.3v output) & #3 (Ground) of Ams1117 to power the Wi-Fi module.

Rest other pin connections is similar as - https://medium.com/@cgrant/using-the-esp8266-wifi-module-with-arduino-uno-publishing-to-thingspeak-99fc77122e82.


Esp8266 | Arduino
---------------------------
RX | RX
TX | TX
GPIO 0 | None
GPIO 2 | None


Arduino | Arduino
---------------------------
Reset | GND


Esp8266 | Esp8266
---------------------------
Vcc | 3.3v ( external - AMS1117 )
CH_PD | 3.3v ( external - AMS1117 )
GND | GND ( external - AMS1117 )

Observation:
1. On powering up Arduino (Via USB) & esp8266 (AMS1117)- red LED was constant but the blue LED was flickering rapidly. I saw AI thinker WiFi SSID , which assigned 192.168.4.x ip to my cellphone.
2. Arduino IDE's serial monitor: except 115200 baud rate, the terminal was getting filled with garbage characters at all baud rates. At 115200, the terminal was quiet, and for few “AT/AT+GMR” commands i got garbage symbols in response. (after wards , garbage response stopped - till i re-powered on Wi-Fi)

Then, after putting GPIO0 to ground (programming mode)

Esp8266 | Arduino
---------------------------
GPIO 0 | GND

i tried uploading code, ang got following -


Global variables use 27968 bytes (34%) of dynamic memory, leaving 53952 bytes for local variables. Maximum is 81920 bytes.
warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed
error: espcomm_upload_mem failed

tried adding 1k resistor with GPIO-Ground, but it didn’t work!!

But, when i connected Wifi Module to 5v of arduino as -

ESP8266 | Arduino
---------------------------
Vcc | 5v
GND | GND

Observation :
1. On powering up Arduino & esp8266 - red LED was constant but the blue LED was off. I saw AI thinker WiFi SSID , which assigned 192.168.4.x ip to connecting devices .

2. Arduino IDE's serial monitor: on 115200 baud rate the terminal was quiet, and for “AT/AT+GMR” serial commands i got expected response. The blue LED flickered only when i entered AT / AT+GMR command. But the chip heated up (i disconnected as soon as i sensed this 😉 )

sl l ⸮ ⸮ |
Ai-Thinker Technology Co. Ltd.

ready
>AT
AT

>AT+GMR

AT version:1.2.0.0(Jul 1 2016 20:04:45)
SDK version:1.5.4.1(39cb9a32)
Ai-Thinker Technology Co. Ltd.
Dec 2 2016 14:21:16
OK

OK

Same observation with 3.3v -

sl
Ai-Thinker Technology Co. Ltd.

ready
>AT
Ai-Thinker Technology Co. Ltd.

ready
AT

OK

With aforementioned experiments it seems that this is power supply issue - as on using arduino's Vcc & GND, things are moving forward.
But i understand that should not rely/use those pins for ESP. Could you please suggest something on this issue - to power the WiFi module externally?.

August 30, 2018
5:26 pm
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cstapels
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Your issue seems to be related to the ESP hardware. You might try posting this issue on an ESP forum. Here is one I found:
https://www.esp8266.com/index.php

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