Avnet M14A2A stand alone

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rob adrian's picture
rob adrian
Junior(0)

Good Morning All,

I have a project that is based on a RPI3 running Windows IoT.  The goal has always been to use the Cellular Module as a stand-alone modem using AT commands.  At the moment, I am by-passing the RPI and have connected straight to my PC via usb.  I am powering the unit via the provided 2.1A 5v supply and using Termite as a terminal program.

 

The issue I have is that no matter what I do, I cannot get ANY feed back from the unit.  I have two of them, and it remains consistent across both units.  I have done nothing in terms of modifications.  The unit has power, and a very inviting "All is well" green led that shines proudly.  However, that said, it refuses to do ANYTHING from there.  The PC does recognize the serial device at least.  

What am I doing wrong here?  This must be something stupid.on my behalf.  I would have expected that power cycling the modem card would have at least output something.  I have also attempted AT, AT+, ATE=1, all of which resulted in crickets.

I need help desperately as this project will be part of a next round funding effort on Friday.  If I can't communicate on the AT&T network, we are dead in the water.

 

I appreciate any and all help!

 

Rob

LightCollector's picture
LightCollector
Moderator(20)

Hi Rob,

 

The 14A2A has multiple serial ports and for a Windows platform it requires custom WNC window's drivers, Windows 7 is the most reliable platform, other Win OS's have caused some issues for others.  Using the 14A2A from windows is not officially supported but it can still made to work with a PC by following the installation instructions exactly.  These instructions are intended to perform a firmware upgrade but in doing so the needed usb device drivers will be installed.  Once installed you will have to locate the proper AT command serial port out of the bunch.  The instructions are here: 

 

https://starterkit.att.com/tutorials/cellular-shield-firmware-upgrade

 

The Raspberry Pi Rasbian OS has the USB device drivers built in but I do not know about Windows IoT on the Pi and whether it has built in drivers.  I am skeptical that it would but I have never tried the module with it.  By using lsusb on the Raspian OS on the Pi, it will give you detailed USB device info.  Once you have those details you might want to try and ask the Windows IoT for Pi experts.  I don't have any contacts for Windows IoT on the Pi that we could ask at the moment so the best I can recommend is an appropriate forum or follow the Microsoft web page for potential contact info.

 

Also, if you already have the drivers installed on your PC, the serial baud rate should be 115200.

 

Best regards

rob adrian's picture
rob adrian
Junior(0)

Thank you LightCollector.  After I posted, I started reading all posts, related or not, and noticed you are VERY patient having answered the same questions over and over and over again.  I do realize that I too asked the same question as someone else, albeit 6 months ago.   

My goal is to be able to drive the shield without a host at all, straight rs-232 via a UART.  I did see another person had similar intentions but the thread never really  vetted out how.  My vision had been to apply 5v to the board, communicate via Max232 3.3v to Uart1 Tx and Rx and call it a day.  Sadly it hasn't quite worked like that.  In fact the unit stares at me blankly.  Any ideas on this one?

Thank you again!

 

Rob

LightCollector's picture
LightCollector
Moderator(20)

Hi Rob,  It will not talk through the serial UART until a special (and illogical) sequence of GPIO pin manipulations are performed.  The level translators on the Shield have to be enabled with a pin and the 14A2A has to see a special sequence of a couple pins in order for it to enable the serial UART control mode.

 

Which pins and how are not documented anywhere except in the code that runs on the K64F when the Shield is used with the Freedom board kit.  Specifically the WncControllerK64F class method WncControllerK64F::initWncModem.  Simliarly the out of the box demo code which is more C like, has a function that demonstrates the sequence (mdm_init in cell_modem.cpp of the Avnet_ATT_Cellular_IOT project).  All code examples can be found at:  https://developer.mbed.org/teams/Avnet

 

Best regards