GSM-GPS Shield stops functioning after connecting to Arduino

Question

I have recently purchased an Arduino compatible SIMCOM SIM808 GSM-GPS-GPRS shield. I was thinking of trying out the AT commands to see how I could play with it, so I connected it to my Arduino UNO R3 in the following manner: -

I have followed the instruction given in this site

VIO connected to +5V of Arduino

GND connected to GND of Arduino

RX connected to Digi Pin 11 of Arduino

TX connected to Digi Pin 10 of Arduino

Additionally, based on the suggestions found here on StackOverflow, I have connected my GSM/GPS/GPRS Shield to a 12V--1Amp external power supply.

And my Arduino draws power from my Computer via USB.

To my surprise whenever I connect my Arduino, the NWK & STATUS LEDs blink for the first few seconds & then finally stop blinking. When I restart my Arduino & the shield and the same thing repeats. I haven't been able to find out any solution for this on Google, hence StackOverflow. If any similar article exists that I may have overlooked, please link it.

Thank you for your time

Answer 1

The input of your shield is 3.4V - 4.4V DC not 12V. In addition it's recommended (see your datasheet, hardware specifications) that your power supply can deliver up to 2A.

Please, read chapter 4.1 Power Supply for further recommendations from the vendor.

And then, you need to power up your module. You need to supply a logic LOW to your PWR pin for 1second and then release it.

Please take a look to my answer to your older post if you ever want to use it with the Arduino GSM library.(Arduino GSM GPS Shield doesn't do the GSM_READY check)