Boron can't connect to cellular when not computer USB powered

Hi all,

I have a similar issue to this previous post where the Boron will only connect to cellular when connected to my computer via USB (power + data), except when I use only a USB power cable (no data) the Boron only flashes green.

What works:

  • Connect Boron via USB to computer
  • Boron boots and connects to cloud normally
  • I'm able to see the Boron in Particle Console and see Log messages over serial
  • Device OS 4.2.0 with internal SIM

What doesn't work:

  • Connect Boron via USB to computer using power cable only, or connect Boron via USB to a 5V USB power supply
  • Boron light briefly illuminates white, then immediately starts flashing green. Every ~40 green light flashes, Boron briefly illuminates white, then resumes green flashing

Edit: Boron LTE-M BRN404X with no LiPo

  • Which Boron (LTE or 2G/3G)?
  • Are you using the LiPo battery?

If you are using the 2G/3G without a battery you will need to change some power manager settings. In the absence of a USB host using DPDM (current negotiation) the input current limit will be set at either 100 mA or 500 mA, which will not be sufficient to connect to cellular.

Sorry just added the info. Boron LTE BRN404X with no LiPo.

I resolved this issue - the Boron seems to get stuck in the "searching for internet" mode (flashing green) when insufficient power is provided.

I had other devices connected to the Boron Vin bus which can demand more than 0.5A at times. My computer USB-C port could provide this, but the other USB-A ports could not. So the Boron was stuck flashing green. I verified this with a bench power supply current limit.

Thanks for your input!