No AT Connection mDot -> Conduit

[Patrick Phillips]

Hi,
> Though different circumstances, this post is similar to Adhavan Manickam’s, and I have read other threads.

I am new to sending AT commands, but it seems fairly straightforward.
I’ll try to set up the entire scenario here:

• I am using an mDot on a UDK connected to my USB port with a USB/Serial cable.
• I have up to date firmware.
• My UDK and conduit antennae are removed.
• The UDK is next to the AEP conduit.
• I’ve fired up Terminal and my cursor freezes/cannot type on screen (screen /dev/tty.usbmodem3a23 115200).
• I’m on a Mac and have attempted to use CoolTerm — it connects and displays commands, but there is no ACK on any of my inputs.
• I purchased a second USB to Serial cable — no difference in behavior.
• By defalut the Stat Com light on the UDK is red — and only after attempting to update firmware does the light blink then go green.
• I am still (with this arrangement) receiving CRC errors.
• There is “received” and “sent” data in the logs (don’t know what that is…)

I hope this is enough information for you to make an educated guess. I do have another developer board and mDot, but want to exhaust my options with this one before trying it.

Thank you!

• This topic was modified 8 years, 6 months ago by Patrick Phillips. Reason: altered name of port

[Jason Reiss]

AT-Commands will be accessible on the serial port of a UDK board.

On the usb port of the UDK board debug output can be seen if enabled.
Use AT+LOG=6 for the highest level of output.

Be sure flow control is off.

I use minicom on mac. I did try CoolTerm and was able to access at command port.

The light on the UDK will be red until firmware is flashed, that is OK.

[Patrick Phillips]

Thanks!

Alas, minicom to the /dev/tty.usbmodem3a23 port freezes too. (no print to screen/typing commands or OK.)

How do I send AT+LOG=6 to the usb port to in order debug?

(Seems my cable/USB port may be shot. At least it’s consistent on Terminal/minicom/CoolTerm … learning the hard way.)

Thanks a lot for your help.

[Jason Reiss]

At commands issued to the serial port.

USB is debug output only.

There is a bootloader on the USB that is accessible if you press enter key right after reset.

[Brandon Bayer]

Patrick,

The mDot has two serial ports:
1) Serial over USB (which you are using). By default this is for output logging only.
2) Serial through the UDK’s DB9 connector. By default this is used for AT Commands,

So you’ll need to use the DB9 connector to issue AT commands.

Make sense?

-Brandon

[Patrick Phillips]

Hi Brendan,
Thanks. Yes, I’m hip to that. These two things may be help you orient you to my issue:

Serial Cable
Have purchased and connected two different (USB to Serial) cables to the DB9 – still haven’t been able to get my AT commands into the mDot UDK. (Tried Terminal, minicom and CoolTerm too.) Tried two different UDKs.

I’m on a mac if that makes a difference to you.

mDot Firmware
As for the device recognizing the commands, I also do not know if I have been able to flash the mDot firmware. When I copy the latest into the MultiTech directory, the UDK blinks then the ‘drive’ remounts. Is this ‘normal’ behavior?

Thanks.
Patrick

[Brandon Bayer]

Patrick,

Ah, ok I understand your cable setup now. That should work.

Yes, that sounds correct for firmware flashing.

Which firmware are you loading on the mDot? You should be using the AT Command Firmware available from the Downloads page.

-Brandon

[Patrick Phillips]

Brandon,

Yes, that’s the one. Once the firmware is up-to-date Does the light ‘go green’? Or, is the Stat Com light always initially red (as in my case.)

Is there a set-up you know to work for getting AT commands from a Mac into the UDK?

Lastly, I will be receiving a EVB tomorrow. It the process for joining the EVB mDot a different in any way? Want to try to be ahead on this…

Patrick

[Brandon Bayer]

Patrick,

The lights as you see them are correct. From everything you’ve described, your setup should be working.

Please create a support case for this.

The EVB is basically an mDot with sensors attached, so it should be very similar.

-Brandon

• This reply was modified 8 years, 5 months ago by Brandon Bayer.

[Patrick Phillips]

Brandon,

Thanks. I did create a support case on the 4th of Nov.

(https://support.multitech.com/support/case.html?action=view&id=65772)

Haven’t received a reply as yet.

Thank you again for your attention and help!

Patrick

[Jason Reiss]

You could also try to create a simple mbed program that just echos the serial input and try each interface in the program to trouble shoot without the AT firmware.

Serial Port pins: XBEE_DOUT, XBEE_DIN
USB Port pins: USBTX, USBRX

#include "mbed.h"

Serial pc(USBTX, USBRX); // tx, rx
// Serial pc(XBEE_DOUT, XBEE_DIN); // tx, rx

int main()
{
    pc.baud(115200);
    
    pc.printf("hello\r\n");
    
    while(1) {
        if(pc.readable()) {
            pc.putc(pc.getc());
        }
    }
}

[Brandon Bayer]

Patrick,

Ok, sorry about the delay. I’ll try to get that moving.

-Brandon

[Patrick Phillips]

For other’s benefit troubleshooting similar, non-responsive USB-Serial issues, it was also suggested I might ‘jump’ pins 2 and 3 on the male end of the serial cable (#1 is top left.)

Try to do a basic loopback on the cable itself. Just connect pins 2 & 3 on the male DE-9 end of the cable. Pin 1 is the upper-left pin as you look at the male DE-9 end of the cable.

Maybe it’ll help somebody.

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