A20 ? The new Gprs/Gsm product


If you read the infos about A6/A6C/A7 in this pdf: http://wiki.ai-thinker.com/lib/exe/fetch.php/modules/datasheet/a6/ai-thinker_a6_a7_a6c_at_v1.02.pdf you can notice in the title there is also the A20 but i found nothing about this module in internet it’s because they actualy work on it, we can find the information here : http://wiki.ai-thinker.com/lib/exe/fetch.php/modules/datasheet/a6/a6_a6c_a7_datasheet.pdf

So the A20 will combine WIFI/GPRS/GSM/CAMERA, they are the same poeple who made the ESP8266 so maybe they will use this chip for the A20.

There is nothing in the datasheet about the wifi so idk why exacly they added the A20 name, and for the second page they said in chinese “to be updated” and “See full functional test board reference schematics”.

EDIT: I found in a doc here: https://drive.google.com/drive/folders/0B6uNNXJ2z4CxZjZXdy10endmZXM more info about the A20, they will use the 8285 chip for the wifi!

Here is the pin description:

More pictures:




So maybe thx to this chip it will be easiest to find a solution for program the A20 with the Arduino environment… I hope.

The google Drive link come from here: http://www.dx.com/p/gprs-a7-serial-gprs-gps-module-core-developemnt-board-for-arduino-445823#.V9HzFpiLSUk


12 thoughts on “A20 ? The new Gprs/Gsm product

  1. Did you guys succeed in flashing new firmware for the WIFI module?

    No matter what proven/tested firmware I flash on that device I get back constantly the following error:

    Fatal exception (28):
    epc1=0x4000228b, epc2=0x00000000, epc3=0x00000000, excvaddr=0x000000b5, depc=0x00000000

    any ideas?


  2. Hi, i have an A20 module with ESP8266. The AT commands sent through uart port work fine, i have been able to take a photo and send it using GPRS. But all the commands sent through the wifi serial porl return ERROR, except AT that returns OK.
    Has anyone been succesful in use the wifi with the A20?


  3. I have spent the weekend playing around with this board. A few things that I have discovered that may help people out, who are trying to figure out why things don’t seem to work with the WiFi portion of this board and in particular the UART communication and chip flashing.

    The flashing part:
    I have the Electrodragon module linked by SK above. Despite the fact that esp8266 is etched into the module housing, this board really has an esp8285 chip. Using the Arduino boards manager, upgrade to ver. 2.3.0 of the esp8266 core (current as of this post) and select generic esp8285 when flashing. I had to set the bit rate to 115200 for the flash to work. Also remember that the chip must be placed into flash mode.

    Enable Flash mode for the esp8285:
    1. power down the board
    2. connect WI 00 to ground
    3. connect power to the board.
    4. flash using WRX0 and WTX0 for the Rx Tx connections

    Connecting the esp8285 to the GPRS UART:
    (For control of the camera and GPRS via esp8285 AT commands)
    As mentioned above, I have the Electrodragon supplied A20. However, my dip switch is mounted backwards. If your dip switch is mounted such that the ‘On’ position is to the outside of the board it is backwards. As a result, flipping switches 2,4 (for wiring esp8285 GPIO13 and GPIO15 to GPRS UART), switches 3,5 need to be on. Very irritating to discover! Also, if using the esp8266 arduino core the Serial needs to be swapped so that is uses GPIO13 and GPIO15 instead of GPIO01 and GPIO03. To do this call Serial.swap() after the Serial.begin. http://esp8266.github.io/Arduino/versions/2.2.0/doc/reference.html

    Here is a working example that takes a picture using the flash every few seconds.

    void camCfg()


    void camCap()

    void setup() {

    Serial.swap(); //swap to GPIO13 and GPIO15


    void loop() {



    Liked by 1 person

    1. Thank, sorry i’ve been away for a long time, the bad side about Serial.swap() it’s we can’t have the return (because i think with Serial1 there is only Tx for the Esp8266), i use this “special” SoftwareSerial for the Esp8266 for be able to use to Serial connection (so with Gpio13 and Gpio15)


      1. You are correct. I missed the Rx limitations on Serial1. I have not had a chance to play with this board since I made that post. I am hoping to get some free time soon so that I can switch over to the software serial approach.


  4. A BIG thank you Scott !!!
    Your explanation saved me a lot of time and gave me very useful hints. I was able to flash non-Arduino custom program(s) using the standard esptool.py and setting the SPI MODE to “dout”. Also I set, as recommended from you, switches 3 and 5 to ON, the rest to OFF and I was able from the ESP module to communicate with the A6(GPRS+Camera). These were the key things that I was missing to make my application working.
    I am planning on writing an article about the module so stay tuned.
    Thanks again.


    1. Hey, did you write an article? )
      I’m trying to flash mine and it’s not even connected as COM port my machine.

      Do you need special driver for windows or switch settings?



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