Unable to configure LTE modem

h3robotics

Hi,

I purchased the LTE V2 Pro with Sierra North America modem installed (https://www.modalai.com/collections/blue-uas-framework-components/products/m0130-3?variant=48186331726128). I am trying to set it up on my VOXL2 with a Canadian sim card from Rogers. I know the SIM card works (and APN is correct) since I have used it in another Quectel modem.

I run the "voxl-configure-modem" command and set the following:

Type of modem: 1) v2
connect to ModalLink: 2) no
APN: 7) custom
custom APN: lteinternet.apn
modem region: 1) Americas

After this it just gets stuck at "Waiting for ttyUSB2..." and does not proceed further.

I have tried this a couple of times but without any success. Previously I was using a wifi dongle connected via the USB3.0/UART expander. I have removed it to plug in the LTE modem.

Kindly help to set me up with the LTE modem. Thanks.

tom

@h3robotics It seems as though the modem itself is not being detected. Can you ensure that the add-on board is fully seated onto the VOXL and that both connectors are fully connected?

h3robotics

@tom when I was plugging in the modem, it did seem that the J1 connector does not go all the way in. But it is because of some small resistors that don't let the LTE modem seat completely.

I am attaching some pictures. Pic 1 and 2 shows the J1 connector side and the small resistor components.

Let me know if there is a solution to this

Alex Kushleyev

@h3robotics , the clearance is indeed very tight between the small capacitor and the beige 12-pin JST GH connector. However, in fully seated position of the add-on board into VOXL2, the JST GH connector does not touch the capacitor - your image shows the fully seated connection with slight clearance.

Alex

h3robotics

@Alex-Kushleyev I agree. When I put in the USB3/UART Add on board, I see that there is some clearance b/w the JST connector and the LTE board.
So it looks like the LTE modem is seated in properly. Looking forward to a solution to my problem of LTE setup

tom

@h3robotics If the hardware is all good you should see the Sierra wireless device enumerate with lsusb and well as the network interface, wwan0 enumerate when you check ifconfig

h3robotics

@tom can you look at this topic I just created. It turns out I was wiring the 4-in-1 ESC wrong as per a wiring diagram in the documentation.

https://forum.modalai.com/topic/4366/error-in-voxl-mini-4-in-1-esc-diagram

Alex Kushleyev

@h3robotics , I believe you are correct that there is an error in the diagram. We will fix the diagram asap and work with you to make things right. Please give us a chance to evaluate what actually happens if the boards are connected in the way our diagram shows. Basically, it seems like the 3.3V from VOXL2 would be shorted to the GND on the ESC, but it needs further analysis.

Alex Kushleyev

@h3robotics , are you able to confirm ESC functionality without VOXL2 by connecting it to a power supply and usb-to-serial adapter (GND, RX, TX) to a Linux workstation? You can use voxl-esc tools to scan and test spin the ESC: https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-esc/-/tree/master/voxl-esc-tools?ref_type=heads#scanning-for-escs

Also, as you connect the ESC to a power supply (lets say 12V), please note the current draw, which should be around 20-30mA for an idling ESC (motors not spinning) without any load connected to its power regulator outputs. Also, you can verify the blue LED behavior as described here:

https://docs.modalai.com/voxl-escs/faq/#q-what-is-the-behavior-of-the-four-blue-on-board-leds

Furthermore, please use a volt meter to confirm that the voxl power output from the ESC is at 5.0V. This regulator feeds VOXL2 but is also used for the ESC itself (as the first stage of power regulation).

Alex