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Topic: SIM800L not responding to AT command on Serial Monitor (Read 184 times) previous topic - next topic

Samkusenuh

Mar 20, 2019, 02:22 pm Last Edit: Mar 20, 2019, 02:38 pm by Samkusenuh Reason: markup
Dear fellow Arduinions,

Im currently connecting my Arduino with my SIM800L module according to https://lastminuteengineers.com/sim800l-gsm-module-arduino-tutorial/

The SIM800L module is blinking once in 3 sec so no issues there.
However, when I want to send my first "AT" command via Serial Monitor I get no response at all...
baudrate is set to 9600 and "both NL & CR" is selected in the monitor.

The module is powered with a LiPo 3.7 v 1500 mA battery.

I already shortened 2 connections from the battery to the sim module because other forums on the internet mentioned that long cables are a common cause for not responding. (see attached foto's)

Any ideas where to possible cause may be hidden? Thank you kindly in advance.

Samuel Kusenuh

freaklabs

Is there a USB interfacce where you can test things? If not, then best to write up a simple interface to echo commands to the GSM module. Also make sure the baudrate is set correctly on it. Sometimes the modules may be set at a different baudrate than you expect. Make sure 9600 is the default in the datasheet.
FreakLabs
Wireless Technology for the environment, wildlife, and agriculture
https://freaklabs.org
https://hackerfarm.jp
Twitter: @freaklabs

Samkusenuh

Hi Freaklabs,

thanks for the valuable input.

I want to try your recommendation. With testing via USB interface, I would probably need as USB-to-serial device like the one in the following link right?

https://www.electroschematics.com/wp-content/uploads/2017/12/4-Serial-Setup.jpg

Or is it possible to do the testing via the arduino, similar as how I am currently (trying) to interface with the SIM800 module.


Cheers,

Sam

freaklabs

Hi Samkusenuh.
I'd recommend to remove the Arduino MCU from its socket and use the board as a USB/serial interface. Otherwise, pick up a USB serial interface and try to talk to the board. Once you have established that communications is possible, then try to automate it via software.
FreakLabs
Wireless Technology for the environment, wildlife, and agriculture
https://freaklabs.org
https://hackerfarm.jp
Twitter: @freaklabs

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