Mini Pro and SM5100B not talking

Wireless & IoT
1

We want to use the SM5100B iGSM/GPRS modem in a product that is centered around the Arduino Mini Pro

The Sparkfun and Cutedigi GPRS shield works VERY well when attached to an Uno.

The GPRS shield, when cabled to the Arduino Pro Mini does not appear to communicate with the Arduino Pro.

When we connect the GPRS shield to an Arduino Mini Pro, we get no visible results.

The sketch is the same in both cases, using softwareSerial.

The GPRS shield is alreay set to 9600 and tested on the Uno.

Connections between the power supply and/or Arduino and the GPRS shield are:

PS +5 or +12 to GPRS shield ‘raw’

PS and MINI Gnd to GPRS shield Gnd

d2 to GPRS shield d2

d3 to GPRS shield d3

No other connection appear to be made between the GPRS shield and the Uno but that works.

We have tried 3.3V and 5V Arduino Pro Mini. We have tried using 5V to the 5V pin, also 12V to the Raw pin.

Voltages on the GPRS sield at the regulator are similar, 3.7-4.1VDC regardless if Uno or Pro.

Any Ideas?

2

I’m having a similar problem: connecting the Pro Mini to a Wave Shield. The shield works fine with the Uno. I’ve tried powering the shield via the Raw and the VCC pins on the mini. only other pins needed by the shield are 2,3,4,5, 10,11,12, & 13; all are connected. What am I missing?

thanks