AT commands work on UNO but not 101

I was recently using a GPS/GPRS/GSM shield for the Arduino.GPS_GPRS_GSM_Module_V3.0__SKU_TEL0051_-DFRobot

I was initially using this on an Arduino 101 but to no avail. I switched to an Arduino UNO and it worked perfectly. I used a 12V 2A external power supply, as recommended on the wiki, in both cases.

I was told this was due to the operating voltage of the 101 being 3.3V and the UNO having an operating voltage of 5V as the AT commands require 5V.

However I have looked online and can't find anything to support this and I'm not sure why it would work on the UNO but no the 101 given that they both used an external power supply anyway?

Any help would be much appreciated.

Did you use the correct library file? For the 101 you need the gps_gsm_sim908.h file while the UNO needs the gps_gsm_sim908Serial0.h file. I couldn't find the code you used for testing in you post (as the sticky post at the top of the forum describes), so this is just guess-work. Provide the necessary information to enable us to help you.

I was told this was due to the operating voltage of the 101 being 3.3V and the UNO having an operating voltage of 5V as the AT commands require 5V.

The 101 should be 5V savvy on the IO pins so this shouldn't be an issue.