# Quick Question About the USB Power Output of the 5G Modem Add-on

Source: https://forum.modalai.com/topic/2423/quick-question-about-the-usb-power-output-of-the-5g-modem-add-on
Category: VOXL 2 and VOXL 2 Mini (https://forum.modalai.com/category/26/voxl-2-and-voxl-2-mini)
Tags: voxl-2
Posted: 2023-07-14 16:43:39 UTC by John Nomikos 0
Replies: 11 · Views: 1863

## John Nomikos 0 · 2023-07-14 16:43:39 UTC

Good afternoon,

I was wondering how many amps the 5G modem hat delivers through it's USB ports. I am trying to connect a doodle radio to it, and the specific one I'm using requires 2 amps of current to function. I know the USB Expander Board v2 delivers 2 amps through its ports, but I am curious if the 5G modem Add-on does as well. 

I am leaning towards no, since the doodle radio isn't powering on when plugged into the USB port of the 5G modem add-on. But I would like to know if my idea that the add-on only delivers 1 amp is correct.

Thank you!

## Reply by tom (ModalAI staff) · 2023-07-14 17:14:57 UTC

@John-Nomikos-0 You're correct in that it doesn't provide the higher level of current that the USB Expander Board v2 does

## Reply by John Nomikos 0 · 2023-07-14 18:06:55 UTC (in reply to tom)

@tom I'm having trouble getting it to detect on lsusb and I'm not getting anything for eth0 when I do ifconfig. I did voxl-configure-modem and selected doodle. 

Do I need to power the VOXL2 with a power module v3? I might be powering it with a power module v2 right now.

## Reply by John Nomikos 0 · 2023-07-14 18:29:04 UTC (in reply to John Nomikos 0)

For reference, it is the miniOEM Mesh Rider Radio

https://doodlelabs.bitbucket.io/datasheets/miniOEM/miniOEM-2450/

## Reply by tom (ModalAI staff) · 2023-07-14 20:01:58 UTC (in reply to John Nomikos 0)

@John-Nomikos-0 Can you post a pic of your setup? You won't be able to power the Doodle modem from one of the 5G carrier's USB ports

## Reply by John Nomikos 0 · 2023-07-17 15:40:04 UTC (in reply to tom)

@tom Here's a photo of my setup. I have a meeting with someone from doodle labs in like an hour, so maybe they will know what is wrong. The radio is not even getting detected with lsusb.

I double checked the pinout and wiring and it seems correct.

Also, the specific port I'm plugged into is the USB port, and it does take 5 volt in. So it is odd that I'm having issues.

I am on the nightly build (1.6.2-M0054-14.1a-perf-nightly-20230614). I think I'm going to flash a different voxl2 platform and see if that does anything.

![c10da239-d2ea-4451-8eaa-4c3218fcbcc3-image.png](https://forum.modalai.com/assets/uploads/files/1689608350353-c10da239-d2ea-4451-8eaa-4c3218fcbcc3-image.png)

## Reply by John Nomikos 0 · 2023-07-17 16:02:34 UTC (in reply to John Nomikos 0)

This is the pinout of the port I'm using

![f9c4a8a3-1e02-4eea-a0a2-3277ee0dba2d-image.png](https://forum.modalai.com/assets/uploads/files/1689609751311-f9c4a8a3-1e02-4eea-a0a2-3277ee0dba2d-image.png)

## Reply by John Nomikos 0 · 2023-07-17 16:18:39 UTC (in reply to John Nomikos 0)

Also, I feel the doodle radio getting warm so it is definitely getting power

## Reply by John Nomikos 0 · 2023-07-17 16:57:51 UTC (in reply to tom)

@tom Got off the meeting with doodle labs. Appears that the problem was that I was connected to USB HOST rather than USB DEV port. USB HOST will assume the device is acting as a host. 

USB DEV basically does ethernet through usb. 

![c3b94b87-5d83-40ad-9f8d-fffde6a3eecb-image.png](https://forum.modalai.com/assets/uploads/files/1689613046078-c3b94b87-5d83-40ad-9f8d-fffde6a3eecb-image.png) 

Going to try this on the VOXL2 using external DC power input to power it up. Hoping it's going to work right out the gate

## Reply by John Nomikos 0 · 2023-07-17 17:15:06 UTC (in reply to John Nomikos 0)

Tried on VOXL2, and it is now showing up in lsusb and eth0 is being assigned an ip!

## Reply by Vinny (ModalAI staff) · 2023-07-18 05:13:56 UTC (in reply to John Nomikos 0)

Hi @John-Nomikos-0 
Each USB port on the 5G modem board is capable of 1A output at 5V, which should be more than enough for some low-power (shorter range) Doodle tests.
Our newest flavor of the 4G modem we have has a dedicated 2A port for VBUS specifically meant for Doodle use cases.
Please also remove any CCAs from the surface of the ESD bags. The outside of those static shield bags are an insulator and can build up charge on the PCBs. Also, if the exterior coating is scratched off they can reveal the shielding bag's inner conductive surface.
Thanks!

## Reply by John Nomikos 0 · 2023-07-18 19:59:36 UTC (in reply to Vinny)

@Vinny Ah I did not know that. Thank you for informing me, I will not put PCBs on ESD bags anymore. I don't want to risk breaking any boards

Also, it turns out that the 2023 model of doodle radio has a separate port for power and USB. So we chose to power the doodle separately instead of daisy chaining one port on the VOXL2 to two ports on the doodle.
