AT commands?

[Jon Ross]

I’m going crazy. I cannot get the AT commands to function on an mdot. I can load code quite happily onto the mdot, look at the debug interface, get it to talk to a conduit mlinux gateway. No problem. In my com ports I see the XR21V1410 USB Uart device, looking happy. I connect to it with terraterm. Set the flow control off, local echo on. Try both 115200 and 9600 baud rates. Type ? – Nada. Type AT – Nada.
I then tried loading the Mdot_AT_Firmware, which as far as I understand pipes the AT interface onto the debug com port. Still nada.
I should mention I’m using the MTMDK-ST-MDOT to talk to the serial interfaces on the mdot.
I need to test the mdot for the power issue – I’m not getting very good range – about a third what I get when I try the semtech eiger testing units.

[Brandon Bayer]

Jon,

By default, the AT Command firmware uses the serial port through the DB9 connector on the UDK, not the virtual USB COM port.

See if that works for you.

-Brandon

[Jon Ross]

Aha, I’m not using the UDK. I’m using the EVB.
Can I change these lines in the AT firmware to use the AT commands over USB com?
Serial debug(USBTX, USBRX);
mts::MTSSerial serial(XBEE_DOUT, XBEE_DIN, 512, 512);

Thanks!

[Brandon Bayer]

Jon,

Yes, you can!

-Brandon

[Jon Ross]

OK, successfully routed the USB serial to the AT command interface, set the tx power to 20 on the mdot, the tx power to 26 on the conduit. I removed the conduit antenna, unfortunately the antenna on the EVB is soldered on.
So in general, should the ping be 6dBm higher than the rssi?

1 foot distance between mdot and conduit:
at+ping
-78,11.2
OK
at+rssi
-74, -82, -47, -62

6 feet distance between mdot and conduit:
at+ping
-84,12.2
OK
at+rssi
-82, -82, -47, -60

15 feet distance between mdot and conduit:
at+ping
-97,10.8
OK
at+rssi
-96, -96, -47, -71

[Brandon Bayer]

With that setup, the mDot effective transmit power is 23 dBm and the Conduit’s is 26 dBm. So the RSSI should be slightly higher than PING (which it is).

-Brandon

[Jim Maricondo]

I’ve got the same problem and can’t get the AT commands to work on my mDot EVB dev board. I assume that the AT command firmware for the mDot on http://www.multitech.net/developer/downloads/ is designed for the MTUDK2-ST-MDOT.

Can you please tell me exactly what you changed those two lines to in main.cpp in the mDot_AT_firmware project? I’d also like to recompile it for my EVB.

Serial debug(USBTX, USBRX);
mts::MTSSerial serial(XBEE_DOUT, XBEE_DIN, 512, 512);

I assume they are set as is for compatibility with the MTUDK2-ST-MDOT, which uses the DB9 serial port for AT commands.

Thanks,
-Jim

[Jason Reiss]

Just swap the pins.

Serial debug(XBEE_DOUT, XBEE_DIN);
mts::MTSSerial serial(USBTX, USBRX, 512, 512);

[Jim Maricondo]

Worked great, thank you.

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