Tether tablet to MMDVM NOT MMDVM to tablet

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kp4djt
Posts: 25
Joined: Wed Feb 06, 2019 12:40 am

Tether tablet to MMDVM NOT MMDVM to tablet

Post by kp4djt »

Folks,
I have a MMDVM board with Pi-Star running my repeater. I have an old tablet that I have mounted to the repeater to check the dashboard when working with the machine. Several times I have noticed that the tablet has obtained and IP address via the USB port rather than using the Wifi from the RPi (I am connecing the whole system over the Ethernet port), I would like to allow this USB connection to be available at all times but it is hit/miss. When it works I see that the USB link is assigning addresses from the 192.168.50.xx block same as when it acts as a WiFi hotspot, but it is very random in operation. At times I can get it to tether over the USB link but most of the time it will not do so, and I have to link it over the WiFi.

Does anyone know how to make this work every time?
kp4djt
Posts: 25
Joined: Wed Feb 06, 2019 12:40 am

Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by kp4djt »

Has anyone given this thought? I have a tablet I would like to connect to the MMDVM board in this manner, but as I pointed out in the original post it does not always work. I am not sure why.
M1DNS
Pi-Star Team
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Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by M1DNS »

The ip address you mention is in regards to pistar AP. Not one from ur actual network.

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Andrew M1DNS.
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kc7ngc
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Joined: Fri Sep 21, 2018 2:47 am

Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by kc7ngc »

What kind of tablet? What operating system and what version?

Sounds like you are trying to do a reverse tether from the tablet to the pistar over the USB Cable? Where you are connected via an IP connection over the USB Cable from the Tablet to the Raspberry pi?

Being able to do a reverse tether depends greatly on the type of tablet, the OS it's running and in the case of Android whether it's a rooted device or not. On many android devices it not possible due do custom nature of the android build as you don't have enough control over the network stack.
AF6VN
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Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by AF6VN »

I suspect one key to look for is if the tablet support USB OTG https://en.wikipedia.org/wiki/USB_On-The-Go -- that, at least, would imply it can be either host or slave device... But yes -- network tethering may be another factor; I'm not familiar with tablets or phones that can tether to another device and have that other device provide the network connection. Typically, phone/tablet wants to use WiFi(or phone data) for network, and will allow cable connections to devices that don't have WiFi.

--
AF6VN
Dennis L Bieber
kp4djt
Posts: 25
Joined: Wed Feb 06, 2019 12:40 am

Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by kp4djt »

Folks,
Got very busy with family things and let this get off of the radar. Here is what I have:
MMDVM repeater controller.
Samsung 10.1" tablet, trying to remember what rev of Android. I think it is 4.x but
not sure what the x is. I am out of town and cannot look at it now.
At times when I plug the tablet into the USB port on the Pi-Star device it picks up
and IP over the USB connection. I have tried to figure out how it is doing it but never
seem to catch it. I would like to figure out what is going on because I would prefer
to use the USB path rather than the WiFi path on the MMDVM controller. I use the
tablet to display the Pi-Star dashboard when in front of the repeater, very handy for
changing things on a screen that fits my eyes B-].

Being able to use the USB path and and old phone or tablet is a great way to add
some viewability to the repeater and put another older device back into service.

I would like to figure out what triggers the two devices using USB without me telling
them to do so.

Thank you again for the attention, and sorry to be so delayed, but finally got back
here to see it.
kp4djt
Posts: 25
Joined: Wed Feb 06, 2019 12:40 am

Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by kp4djt »

By way the IP address the tablet picks up is 192.168.50.x so it is being assigned
by the Pi-Star device just as though it was over WiFi.
M1DNS
Pi-Star Team
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Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by M1DNS »

192.168.50.1 is the IP add. of the pistar Setup AP. Used for the initial config. setup for its connection to wifi.

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Andrew M1DNS.
Pi-star Admin Team.
kp4djt
Posts: 25
Joined: Wed Feb 06, 2019 12:40 am

Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by kp4djt »

All good, but I am trying to figure out why at times the tablet with get an IP address over the USB link to the pi, that way I do not need to worry about anymore bits and pieces in this. If I could make it always work that way tablet links to raspberry pi over the USB link then I would not have to worry about having a wifi hotspot on the same network as the raspberry pi.

The times it has linked up that way have been excellent but for some reason it is hit/miss. Even with the wifi turned off on the tablet it may or may not connect over the USB. By using the USB I do not need to worry about having anymore hardware. If I take the repeater to a location that provides a network connection but no wifi, there is not any issue, or they may provide a network connection and wifi but they are on different subnets and you cannot get from a to b...

In my view having the path from mmdvm controller to tablet over USB is just cleaner and one less box.
kp4djt
Posts: 25
Joined: Wed Feb 06, 2019 12:40 am

Re: Tether tablet to MMDVM NOT MMDVM to tablet

Post by kp4djt »

I think I have figured it out, I just need to make sure that tethering is turned on as the tablet is going to tether TO the Pi-Star device. I think that it was automatically connecting when it did not find and RF path, for whatever reason. Now I just need to turn on tethering when I plug the tablet in. And figure out how in this case to make that the default network path. Appears that if the RPi sees an IP request over USB it will hand out an address in the same 192.168.50.x block as it does over WiFi. It would appear that the RPi is monitoring both WiFi and USB and if it sees a connect request it will hand out an IP to the requesting device. But the WiFi side times out and after a few minutes drops out if it has not connected. Not so the USB side. Again if I plug in the tablet and make sure tethering is turned on it works. Thank you for your time and info.
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