I have purchased a 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 .
- 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 ⸮ ⸮ | ....#garbage values#......... Ai-Thinker Technology Co. Ltd. ready >AT AT >AT+GMR AT version:22.214.171.124(Jul 1 2016 20:04:45) SDK version:126.96.36.199(39cb9a32) Ai-Thinker Technology Co. Ltd. Dec 2 2016 14:21:16 OK OK[code] Same observation with 3.3v - [code]sl #GARBAGE values..........# Ai-Thinker Technology Co. Ltd. ready >AT Ai-Thinker Technology Co. Ltd. ready AT OK[code] 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?.