Microhard Add-On Board User Guide

Table of contents

1. Overview
   1. Supported Microhard Modem Modules
2. Requirements
   1. Hardware
3. Hardware Setup
   1. Hardware Setup - Master
   2. Hardware Setup - Slave
4. Software Setup
   1. VOXL2 Add-on
   2. Standalone
5. Microhard Modem Command Line Interface Configuration
   1. Reset Modem to Master
   2. Setup Master (AT+MWVMODE=0)
   3. Setup Slave (AT+MWVMODE=1)
6. Connecting to QGroundControl

Overview

The VOXL system supports the ability to easily and quickly add a Microhard wireless connection between a vehicle and a Ground Control Station. The following guide provides you the necessary details on doing so.

Datasheet

Supported Microhard Modem Modules

• 1800MHz pDDL1800 (Buy Here
• 2.4GHz MIMO pMDDL2450 (Buy Here
• 2.3GHz MIMO pMDDL2350 (Buy Here
• 2.4GHz MIMO pMDDL2400 (Buy Here)

Requirements

Hardware

The following hardware is required to establish a Microhard connection between VOXL and a host computer.

VOXL Microhard Modem Add-on	Microhard pDDL Carrier USB Dongle

Hardware Setup

In order for the Microhard modules to communicate correctly, one module needs to be setup as a Master and the other needs to be setup as a Slave.

For the best performance, it is required to connect the Master to the source (e.g. VOXL, Drone, Video Source) and the Slave to the receiver (e.g. PC).

Hardware Setup - Master

• Remove power and USB from the VOXL main board
• Attach an antenna to the ANT connection on the Microhard Modem
• Insert Microhard Modem into VOXL Microhard Modem Add-on, pin 1 should line up with the white dot on the board.
• Attach VOXL Microhard Modem Add-on to VOXL2’s J3 Expansion B2B connector.
• Connect VOXL2 to Host PC via VOXL2’s USBC connector to get adb connection
• Power on VOXL2

Hardware Setup - Slave

• Attach an antenna to the ANT connection on the Microhard Modem
• Insert Microhard Modem into the Microhard pDDL Carrier USB Dongle, pin 1 should line up with the white dot on the board.
• Connect the Microhard USB Dongle to the host PC via the single To USB Host connector on the bottom of the board
• Power the board.

Software Setup

In order to establish a link between the Microhard Modems in a quick and easy way, we can take advantage of the VOXL Microhard Modem Add-on and Microhard pDDL Carrier USB Dongle’s S2 buttons, which act as “reset” buttons for the Microhard Modems.

Before starting, make sure both the VOXL and Microhard pDDL Carrier USB Dongle are powered by following the steps above.

VOXL2 Add-on

In order to enable the VOXL Microhard Add-on board, the following software is required and should already be pre-installed:

• System Image 1.1.2 +
• voxl-modem_0.10.0 +

voxl-configure-modem allows you to quickly and easily bring up a Microhard modem.

NOTE: If using System Image 3.8.0+ on VOXL, voxl-modem_0.16.0+ is required (SDK 0.8.0+)

# On VOXL
voxl-configure-modem

You will first be asked which modem type you are setting up:

What type of modem are you using?

If you are unsure of which modem you have, take a look at the following datasheets:

v1 LTE Modem: https://docs.modalai.com/lte-modem-and-usb-add-on-datasheet/
v2 LTE Modem: https://docs.modalai.com/lte-modem-and-usb-add-on-v2-datasheet/
Microhard Modem: https://docs.modalai.com/microhard-add-on-datasheet/

1) v1
2) v2
3) microhard

Choose 3 for microhard.

You will then be asked for the IP address that you would like to be assigned to your VOXL on the Microhard network.

Enter the IP address you would like to the VOXL to use on the Microhard network:
Note: The chosen IP address must be of the form: 192.168.168.XXX, where XXX is a 3 digit number

Default - 192.168.168.100

1) default
2) custom

Once you choose your IP address, the VOXL will configure the service files that enable Microhard connection on bootup.

Making new interface file /etc/network/interfaces
reloading systemd services
enabling voxl-modem systemd service
starting voxl-modem systemd service
DONE configuring voxl-modem

Now that you have enabled the VOXL’s software to handle the Microhard modem, press and hold the S2 button on the VOXL Microhard Add-on board for at least 10 seconds, then release. The module will then reset all settings to the default values required for a Master module. This module will be assigned a default IP address of 192.168.168.1

After a short time your VOXL will be connected to the Microhard network. You will now be able to reboot your VOXL and have it connect to the Microhard network automatically.

Standalone

The process for configuring the standalone Microhard board is simple:

• Press and hold the S2 button on the Microhard pDDL Carrier USB Dongle for 5 seconds, then release. The module will then reset all settings to the default values required for a Slave module. This module will be assigned a default IP address of 192.168.168.2

Once both Microhard modems have been configured, the two should now automatically connect to each other.

Microhard Modem Command Line Interface Configuration

The following (updated 2024-Aug) has been used to succesfully setup pMDDL2400 master and slave using the command line interface over SSH.

For full list of AT commands, please see Microhard documentation (although Microhard;s website doesn’t have this information (sigh….), we’ve found it here)

Here are some useful commands used below:

Reset Modem to Master

This should be done to both master and slave units at first for initial condition.

1. Pressing and holding momentary button S2
2. Once the CPU LED begins to fast blink on the modem carrier board, hold for ~30 seconds longer
3. Wait until all LEDs but the CPU LED turn off

Setup Master (AT+MWVMODE=0)

With the M0048-1 add-on modem connected to VOXL2, a use case like this is supported:

From VOXL2, SSH onto the modem using user admin and paassword admin:

voxl2:/home$ ssh admin@192.168.168.1
admin@192.168.168.1's password:
Connected to 127.0.0.1

Entering character mode
Escape character is '^]'.

Command Line Interface
UserDevice>

Example setup for master (AT+MWVMODE=0), network id “test”, frequency 2477 MHz

UserDevice> AT+MWNETWORKID=test
OK
UserDevice> AT+MWVMODE=0
OK
UserDevice> AT+MWFREQ2400=76
OK
UserDevice> AT+MWRADIO=1
OK
UserDevice> AT&W
Restarting the services to enable the configurations changed recently......
OK
UserDevice> AT+MSREB
  Rebooting...
OK
Connection closed by foreign host

Setup Slave (AT+MWVMODE=1)

With the M0048-2 standalong modem connected to a host PC (recommended Ubuntu) over USB using something like MCBL-00010. For example, like this:

Example setup for slave (AT+MWVMODE=1):

UserDevice> AT+MWNETWORKID=test
OK      
UserDevice> AT+MWVMODE=1
OK
UserDevice> AT+MWRADIO=1
OK
UserDevice> AT+MWFREQ2400=76
OK
UserDevice> AT+MNLAN=lan,EDIT,0,192.168.168.2,255.255.255.0,192.168.168.1
OK
UserDevice> AT&W
Restarting the services to enable the configurations changed recently......
OK
UserDevice> AT+MSREB
  Rebooting...
OK
Connection closed by foreign host

Connecting to QGroundControl

The VOXL system uses the voxl-mavlink-server service on VOXL to establish a connection between PX4 and QGroundControl over UDP. This is supported on VOXL Flight or when using Flight Core with VOXL (using this procedure).

Locate the IP address of the host PC that has been assigned to it by the Microhard modem. An example output is below:

$ ifconfig

enp1s0    Link encap:Ethernet  HWaddr 48:D7:05:EA:06:36  
          inet addr:192.168.168.135  Bcast:192.168.168.255  Mask:255.255.255.0
          inet6 addr: fe80::4ad7:5ff:feea:636/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:125 errors:0 dropped:0 overruns:0 frame:0
          TX packets:247 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:13399 (13.0 KiB)  TX bytes:31491 (30.7 KiB)

In this case, the IP address of the host PC is 192.168.168.135

If you have not yet setup voxl-mavlink-server on your VOXL, do the following:

# On Host PC
$ adb shell

# On VOXL
yocto:/home/root# voxl-configure-sku -w

yocto:/home/root# voxl-configure-mpa