Microhard Carrier USB Dongles do not work with microhard pMDDL2450

[Ross]

Microhard pMDDL2450 is not recognised by Windows/linux or Android when using the USB of Microhard Carrier USB Dongle.

The error message in Windows can be seen in the attached photo. Android/linux also not working. Tested across multiple PC's and Mobile devices.

We have noticed that all the ModalAI Carrier dongles that use LAN7500 do not work! however all 5 carrier dongles with a LAN 7850 chip work Ok.

We have installed RNDIS in windows as per normal when connecting a new device, Android usually just works however it does not.
This seems to be a hardware issue between Microhard PMDDL2450 and ModalAI carrier dongle.

Is this a known issue? Currently we have around 40 Carrier dongles that cannot be used because of this issue. Please can technical support help look into this.

[Chad Sweet]

We frequently use Linux with those dongles, and switched to LAN7500 3 years ago. They also typically work with recent Android phones/tablets. (Galaxy S20 for instance)

We do not use windows though

Have you tried different cables?

[Ross]

Hi Chad,

The thing we noticed is that the dongles we tested with the LAN7500 do not connect to any platform.
We mainly use Linux for dev and Android to deploy to our customers. Neither work unfortunately.
The few dongles with the LAN7850 all work fine and can connect.

This is not a cable issue, we have working dongles using the same cables.
We have tried multiple different dongles with the LAN7500 chips, all have exactly the same problem.
Power supplied in the lab by Linear Rigol supplies.

Removing the pMDDL2450 from the modal dongle using an extractor tool and adding it into the Microhard eval kit baseboard
and it works fine. (Using the resistor mod to make it USB capable) It appears the radios seem to operate fine.

Perhaps the modal dongle has some component value on the edge? We cannot really debug the modal dongle at the hardware level.
(we do not have schematics and your engineers would be better positioned to do that etc)

The fact the units with the LAN7850 work ok with the exact same radio (extracted and tested the same pMDDL2450)
We really need to urgently solve this, we have 40 units that we cannot use at the moment and a customer delivery looming.

Best Regards,

Ross

[Chad Sweet]

We use these internally and have dozens of customers integrating as well. Can you take a picture of your setup? Are you sure you're plugged in to the correct connector?

On Linux, what does lsusb output?

[Chad Sweet]

Your should be connected like the image below. We test all of the units prior to shipment using a ping between two boards. It is very likely a setup issue

[Ross]

@Chad-Sweet we are 100% sure we use the correct connector.
Like i said we have all 5 x LAN7580 versions working A ok. No issues.

[Chad Sweet]

@Chad-Sweet said in Microhard Carrier USB Dongles do not work with microhard pMDDL2450:

On Linux, what does lsusb output?

On Linux, what does lsusb output?

Can you please send a picture of your Microhard dongle connected to a Linux computer?

[Ross]

@Chad-Sweet Have you tested the LAN7500 dongle version with a recent pMDDL2450 as in our image? You can see the version we have is a pMDDL2450 'G2'. This is the only version that microhard now sell of the pMDDL2450- 'latest version'.
Perhaps there is some incompatibility with LAN7500 whilst the LAN7850 works fine.

We are 99.99% sure this is related to the recent pMDDL2450 and the LAN7500 dongle version. I will repeat that when this pMDDL2450 is inserted into the official microhard eval kit it works and when used in the LAN7850 modal Dongle it works ok. It's only the LAN7500 versions that have an issue. For the first two days of debugging this we also thought we had made a mistake somewhere but we are very confident about the issue.

I'll send you an image of the setup tomorrow once im back in the office.

Best Regards,

Ross

[Ross]

Re: Microhard Carrier USB Dongles do not work with microhard pMDDL2450

Hi Chad, Please see the requested info below.

lsusb of LAN7500 Dongle - not working on any platform.

lsusb of LAN7850 Dongle - Working fine on all platforms - Linux/Android and Windows.

Dongle connected image -

[tom]

@Ross I'm going to replicate your setup right now. However, you can see the LAN7500 device enumerating in your first screenshot. What does ifconfig look like when that same device is plugged in and powered on?

[tom]

@Ross I have replicated your setup as seen below, just using an APM for cable (shouldn't make a difference).

Just like yours, it is enumerating and can be seen in lsusb

You can use ifconfig to look at the list of network interfaces on your host device. It will enumerate as type "USB ethernet"
and will be auto-assigned an IP address by the modem (in the form 192.168.168.*)

As you can see, mine gave my host PC an address of 192.168.168.161

Next, I pinged the modem. My modem was setup in "master" mode, so it has an IP of 192.168.168.1. You can read more about the difference between slave and master modes here: https://docs.modalai.com/microhard-add-on-manual/

It's possible yours is in "slave" mode and therefore has an IP of 192.168.168.2

In order to modify the settings you can navigate in your browser to the IP of the modem, as seen below:

Here you can change modes and modify any other modem settings.

The default login is:
user: admin
password: admin

In order for two Microhard modems to talk to eachother, one needs to be in "master" mode and the other needs to be in "slave" mode. Microhard recommends having the drone be "master" and the ground station to be "slave"

[Ross]

Hi @tom, Thanks.
I will get you a screengrab tomorrow when back at the desk.
This should be easy to replicate your side but you will need the same radio and only using the LAN7500 version of your dongle.
As i mentioned to @Chad-Sweet its the pMDDL2450 - microhard call it a 'g2' revision.
According to Microhard its the only one they sell now.

[Chad Sweet]

You can see in Tom's picture, we are using "G2" as well. This is the most common setup

[Ross]

@tom is this using the LAN7500 version or the LAN7580?
using the LAN7580 works perfect with all the units we have here.
We have 40 of the LAN7500 and the 5 we picked out and tested all have the same issue.

[Ross]

@tom i see from the lsusb it looked like a LAN7500.
If you have the 7500 working there with a g2 version then I am not sure what to make of the boards we have here.
We have used the radios for many years so setting them up is quite normal for us.

[tom]

@Ross Again, what do you see with ifconfig? Are you able to get a network interface up and an IP assigned?