Introduction

Sending commands to a device is a great way to debug issues and figure out what is going on with the modem. This guide will show you how to send AT commands to a Hologram Nova, but the basics apply to any device that has a modem that one can access via serial communications. We’ve broken this up into instructions for Mac users, Linux users, and Windows users. For more information on specific AT Commands check out this guide: Introduction to AT Commands.

Linux

If you don't have Screen make sure to first install it using the following command:
sudo apt-get install screen

Before you plug in your Nova, open the Terminal and type the following command:
ls /dev/tty* 

This should return all the USB devices currently plugged into your computer. Since we now know which devices are not the Nova, it will be easier to identify it once plugged in.

Plug in your Nova and run:

ls /dev/tty* 

Whatever new entries appear is your Nova.

Note that the reason why you get multiple Nova endpoints instead of just one is that the Ublox modem on the Nova allows for things like having an open PPP session on one serial port while being able to execute AT commands for things like SMS or signal strength on the other. Not all of the ports are usable, but in the default mode you should have at least two ports able to accept AT commands.


Next we will open a Screen into the Nova. To do this use the following command:
screen /dev/ttyACMxyz
where xyz is the port your Nova is connected to. The baud rate should be 9600. In this example we omit it because Screen has this baud-rate by default.

This will clear your terminal and take you to the Screen.

To confirm that we are communicating with the Nova type:
at
This is the attention command. Your modem should reply with OK.

If you are not seeing the AT commands you are typing try sending ATE  

Screen does not play nice with backspaces or correcting errors so its best to just hit enter and start you command fresh.

Congratulations you just sent your first AT command!

To exit press CTRL+A followed by Shift+K

and confirm with y

Optionally, CTRL+A followed by CTRL+D will detach your Screen from the terminal session.

Finally, use the command:
Kill
followed by the screen session number which will appear in your terminal when you detach.

Sometimes you will see +UMWI: 0,1; +UMWI: 0,2; +UMWI: 0,3; +UMWI: 0,4 when you open your Screen. This is part of the Nova's boot up process. Feel free to ignore that.

Mac

Before you plug in your Nova, open Terminal and type the following command:
ls /dev/tty.usb*
This should return all the USB devices currently plugged into your computer. Since we now know which devices are not the Nova, it will be easier to identify it once plugged in.

Plug in your nova and run:
ls /dev/tty.usb*

Whatever new entries appear is your Nova.

Note that the reason why you get multiple Nova endpoints instead of just one is that the Ublox modem on the Nova allows for things like having an open PPP session on one serial port while being able to execute AT commands for things like SMS or signal strength on the other. Not all of the ports are usable, but in the default mode you should have at least two ports able to accept AT commands.

Next we will open a Screen into the Nova. To do this use the following command:
screen /dev/tty.usbmodemXYZ
where XYZ is the port your Nova is connected to. The Screen's baud rate should be set to 9600. In this example we omit it because Screen has this baud-rate by default.

The step above should have cleared your terminal and taken you to the Screen.

Notice that our screenshot below shows some commands. Sometimes you will see +UMWI: 0,1; +UMWI: 0,2; +UMWI: 0,3; +UMWI: 0,4 when you open your Screen. This is part of the Nova's boot up process. Feel free to ignore that.

To confirm that we are communicating with the Nova type:
at
This is the attention command. Your modem should reply with: OK.

If you are not seeing the AT commands you are typing try sending ATE  

Screen does not play nice with backspaces or correcting errors so its best to just hit enter and start you command fresh.

Congratulations you just sent your first AT command!

To exit press CTRL+A followed by CTRL+\ and confirm with y

Optionally you can detach your screen and kill it at a later point in time. To do this,  press CTRL+A followed by CTRL+D. This will detach your Screen from the terminal session.

Next run:
screen -ls

to view your Screen's session number.

Finally use the command:
Kill ABCDE

where ABCDE is the Screen's session number which will appear in your terminal when you detach.

Windows

Windows natively offers similar capabilities as those described for Linux and Mac using the MS-DOS command line prompt. However, the process can be a bit messy so we recommend using a terminal emulator tool like Tera Term or PuTTy. Below we will outline the process to connect using both.

The first step for either terminal emulator will be to determine the COM port for your Nova. To do this simply open your 'Device Manager' and open up the 'Ports' drop down. Here you should see various 'u-blox Modem' options. You'll want to find the ones that contain 'AT and Data'. In the screenshot below COM157 and COM160 will work. Make a note of the number, you'll need it later.

Tera Term

When you open Tera Term you will see two options TCP/IP or Serial. Click on Serial.

Next select the Port. As pictured above, there will be a few different options to choose from. Make sure you select one that says AT and Data and hit OK. This will open a Tera Term connection window with your Nova. To confirm that we are communicating with the Nova type:
at
This is the attention command. Your modem should reply with OK.

To close down the communication simply close the window.

PuTTY

When you open PuTTY you will be greeted with the screen above. To begin select the Serial radio button under Connection type: on the right side of the screen.

You should now have the options to enter Serial Line and Speed.

Under Serial Line enter the COM Port you found earlier and click Open.

This will open a PuTTY connection window with your Nova. To confirm that we are communicating with the Nova type
at

This is the attention command. Your modem should reply with OK.

If you are not seeing the AT commands you are typing try sending ATE  

To shut down the session simply close the window.

Sometimes you will see +UMWI: 0,1; +UMWI: 0,2; +UMWI: 0,3; +UMWI: 0,4 when you open your Screen. This is part of the Nova's boot up process. Feel free to ignore that.

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