Hi,
We're building a power meter with networking capabilities and have selected the wnc m18q2fg-1 modem as our modem of choice. We've designed our own PCB following the data sheet and I'm in the process of getting the modem up and running with our linux single board computer.
I'm having some problem with the modem as explained below:
We built a carrier board for the modem and this is plugged into a single board computer. The single board computer recognized the modem and it showed up as an usb ethernet device. However, I could not get it to recognize any sim card.
I've checked our sim detection signal and it seems to be working correctly, sending 1.8V to to modem when a sim is inserted. However, the modem does not produce a Sim VCC to power up the SIM card.
Can anyone tell me what might be wrong with the modem?
Attached is the schematic for the sim card circuit and modem for your reference.
