LTE Modem and USB Add-On Board

Table of contents

  1. Overview
  2. Requirements
    1. Hardware
    2. Software
  3. SIM Cards and Supported Networks
  4. Hardware Setup
  5. Software Setup

Overview

The VOXL system provides the ability to easily and quickly add an LTE connection. The following guide provides you the necessary details on doing so.

Requirements

Hardware

In order to connect the VOXL to an LTE network, the VOXL-ACC-LTE accessory kit is required. These can be purchased through here are are available in two options:

Part Number Description
VOXL-ACC-LTEH-DOD Add-on board for VOXL which enables DOD spectrum LTE as well as adds a USB hub to integrate more peripherals
VOXL-ACC-LTEH-NA Add-on board for VOXL which enables North American carrier LTE as well as adds a USB hub to integrate more peripherals CAT4 LTE Bands 2,4,5,12

Modems

Each kit conveniently comes with two LTE antennas (which are also available here)

Software

The following are required which should already be pre-installed:

SIM Cards and Supported Networks

The modems cards require a Nano SIM.

AT&T, Verizon and T-Mobile are supported. For Band 3 support, the VOXL-ACC-LTEH-DOD modem is requiered and Band 3 SIM cards need to be requested through ModalAI.

Hardware Setup

  • Remove power and USB from the VOXL main board
  • Insert SIM card into LTE card
  • Connect antennas to the LTE card (note that it takes a little force to attach the U.FL connectors…)
  • Attach LTE card to the VOXL’s J13 connector. 3/8” #2-56 nylon screws and #2-56 nylon nuts can be used with a 5mm nylon spacer between the boards.
    • Note: The switch near the antenna connectors should be in the ‘off’ position. When ‘on’, it will force the main board to into USB boot mode
  • Connect the USB cable to the VOXL main board
  • Connect the power supply, you should see green LEDs like

Modem-1

Software Setup

The VOXL ships with utilities on board to setting up the modem. First, initialize the modem:

voxl-modem --feather_configure

note: on some early shipments you may need to use the followig instead:

modalai_modemutil.py --feather_configure

Next, we need to configure the APN. The following shows some sample APNs and how to implement them.

For IoT devices on the AT&T network:

echo "AT+CGDCONT=1,\"IP\",\"m2m.com.attz\",\"0.0.0.0\",0,0,0,0" > /dev/ttyACM0

For laptops and tablets on the AT&T network:

echo "AT+CGDCONT=1,\"IP\",\"broadband\",\"0.0.0.0\",0,0,0,0" > /dev/ttyACM0

For Smartphones on the AT&T network:

echo "AT+CGDCONT=1,\"IP\",\"phone\",\"0.0.0.0\",0,0,0,0" > /dev/ttyACM0

For LTE devices on the T-Mobile network:

echo "AT+CGDCONT=1,\"IP\",\"fast.t-mobile.com\",\"0.0.0.0\",0,0,0,0" > /dev/ttyACM0

NOTE: Use only one APN depending on your carrier and plan.

After issuing the last command, you can check for an OK response using the following:

cat /dev/ttyACM0
(CTRL+C)

Reboot the device to finish configuration.

shutdown -r now

After rebooting, conncet via ADB again and then connect to the network using the following command:

voxl-modem --connect_to_network

note: on some early shipments you may need to use the followig instead:

modalai_modemutil.py --connect_to_network

If successful, you should see the WWAN status LED illumate. This indicates that the modem has successfully registered with the network. You will also see a new network interface rmnet_usb0:

/ # ifconfig
lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:48 errors:0 dropped:0 overruns:0 frame:0
          TX packets:48 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:3504 (3.4 KiB)  TX bytes:3504 (3.4 KiB)

rmnet_usb0 Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
          inet addr:10.39.193.86  Mask:255.255.255.252
          UP RUNNING  MTU:2000  Metric:1
          RX packets:2 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:612 (612.0 B)  TX bytes:1112 (1.0 KiB)

wlan0     Link encap:Ethernet  HWaddr 48:5F:99:9D:55:DF
          inet addr:192.168.8.1  Bcast:192.168.8.255  Mask:255.255.255.0
          inet6 addr: fe80::4a5f:99ff:fe9d:55df/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3000
          RX bytes:0 (0.0 B)  TX bytes:858 (858.0 B)

Modem-3