Powering SM5100 does not work as expected?

Wireless & IoT
1

Hi!

I’m using SM5100 3.3V shield with netduino. I am not using it directly on top of netduino, but it connected via wires.

If I connect ND+ 5V to 5V on a cellular shield, it does not work (I get just some gibberish on a serial interface). But if I connect 5V from ND+ to VIN on cellular shield, the shield starts working. This is somewhat unexpected, since if I was to put it on top of ND+, VIN from ND+ would become VIN on cellular shield, and that does not work, since VIN is much higher than 5V (9+ V in my case) and I tried that as well, and it does not work.

What am I doing wrong?

Regards,

Miha.

2

Miha,

Did you ever solve this?

I am looking to do the same thing.

Thanks!

3

Sure. I am total n00b, but friendly guys at Netduino forums explained that 5V is not connected to shield and you have to power it via VIN.

So just connected VIN - VIN, or 5V - VIN. Be aware that you need external power supply in order for shield to work, since it draws more current than USB provides.

Regards,

Miha.