SIM808 with Arduino Mega

Hello everyone.

I am running the SIM808 with Arduino Mega.

Using AT+ECHARGE=1 to enable and AT&W to store charging a LiPo for backup.

Doing AT+CBC always returns 0 for the first number, which means the LiPo is NOT charging.

Checking AT+ECHARGE? returns 1.

Shouldn´t AT+CBC return 1 in the beginning as well?

Input power is 12v 2a and LiPo is 3,7v 1500mAh.

The module is working fine with only 12v and working fine only with LiPo. The LiPo is just not charging.

Thanks for any help.

Kind Regards,

Jens

Hi Jens,



please take a picture about the hardware connection. thanks.

Hello bill.yu

This is my hook up:

https://photos.app.goo.gl/zEw8oKWr9BVBh2UQ9

Thanks

Hi Jens



I do not have the module, please try below steps. thanks.


  1. Please try List of supported responses, AT+CBC=?
  2. then wait for 1 sec,
  3. then query the current setting AT+CBC

Hello bill.yu



this is the result:



at+cbc=?

+CBC: (0-2),(1-100),(voltage)

OK



at+cbc

+CBC: 0,78,4027

OK



*************** checking if charging is turned on *****************



at+echarge?

+ECHARGE: 1

OK



************** using a different LiPo **********************

at+cbc

+CBC: 0,68,3950

OK



The procentage and the voltage is displayed correct. The charging index (fist value) always remains at 0.

I have 2 of these modules and both doing the same. Also tried Aduino UNO, Mega, Nano… no difference.

Baud rate was changed also.



Kind Regards, Jens