<![CDATA[connect with usb to COM-NB-IOT-MODULESIM7020G fails]]>Hi,
I cant get the USB port on sim7020g modem working. I just connect my PC with a terminal emulator.
The board powers up (red led) and blinking blue NET LED.
However I only get garbage characters on my terminal as if the speed was wrong.
I have tried all speeds without success. Default is 115200 8N1.

It generates 2 USB-devices as other modems like SARA R410 do.
Should it be possible - any clues ?

Olav

]]>https://community.m5stack.com/topic/3841/connect-with-usb-to-com-nb-iot-modulesim7020g-failsRSS for NodeFri, 01 May 2026 12:37:42 GMTSat, 18 Dec 2021 14:48:40 GMT60<![CDATA[Reply to connect with usb to COM-NB-IOT-MODULESIM7020G fails on Wed, 02 Feb 2022 18:33:58 GMT]]>Thanks @felmue,
I have now got the card powered by following your observations :
connecting 5v to VIN, GND to GND, TX to RXD, RX to TXD
I don't need to trigger PWK to get the modem operational.
The modem don't connect to the network, but that's another problem..

]]>https://community.m5stack.com/post/16488https://community.m5stack.com/post/16488Wed, 02 Feb 2022 18:33:58 GMT<![CDATA[Reply to connect with usb to COM-NB-IOT-MODULESIM7020G fails on Tue, 21 Dec 2021 08:46:03 GMT]]>Hello @olavk

no, I don't think P/G is the on/off trigger. It seems to be connected to GND. I think PWK is the power key.

Have a look at the COMX schematic. You'll find this:

  • P/G : is connected to GND

  • GND : is connected to GND

  • PWK : is connected to EN

  • RXD : is connected to GPIO17, GPIO0 or GPIO17

  • TXD : is connected to GPIO16, GPIO5 or GPIO15

  • VIN : is connected to either 5.4 V or whatever is provided at the DC in

  • VIN : dito

  • VTTL : not connected

  • VEXT : not connected

How exactly this translates to an Arduino MKR Zero I cannot tell. I don't have one to try. Sorry.

Thanks
Felix

]]>https://community.m5stack.com/post/15903https://community.m5stack.com/post/15903Tue, 21 Dec 2021 08:46:03 GMT<![CDATA[Reply to connect with usb to COM-NB-IOT-MODULESIM7020G fails on Sun, 19 Dec 2021 07:10:17 GMT]]>Thanks @felmue - Yes I mean the USB on the breakout board. The referred manual states : 'The SIM7020G contains a USB interface compliant with the USB1.1 specification as a peripheral'.
And my intention was indeed to do debugging to see if the modem would connect to the network with my SIM before I start to connect it to my Arduino.

Anyone that have a connection diagram for how to connect this breakout-board to an Arduino (MKR Zero),
as I don't want to use the M5 Stack wrapping.

So I have pins PWR, GND and P/G on one side and VIN VEXT and VTTL on the other side.
Could I expect P/G to be the pin to trigger to power on/off ?

]]>https://community.m5stack.com/post/15870https://community.m5stack.com/post/15870Sun, 19 Dec 2021 07:10:17 GMT<![CDATA[Reply to connect with usb to COM-NB-IOT-MODULESIM7020G fails on Sat, 18 Dec 2021 15:48:01 GMT]]>Hello @olavk

I assume you mean the USB port on the green board plugged into the COMX.NB-IoT module, correct?

If yes, then according to the SIM7020G Hardware Design Guide - chapter: 1.4 Functional Overview the USB port is meant for debugging. Maybe that means it cannot be used to issue AT commands?

Thanks
Felix

]]>https://community.m5stack.com/post/15861https://community.m5stack.com/post/15861Sat, 18 Dec 2021 15:48:01 GMT