My Heltec esp32 dev v3 boards don't power-up using USB port


The title says it. None of my four Heltec WiFi_Kit_32_V3 boards will power-up from USB. I have three USB_C-to-USB_C cables that all work fine to power-up MicroProcessors with USB_C port. The cables are also used, of course, to successfully upload code MANY times. They-re good. I’ve also plugged the cords into a hefty USB_C charging port but that does not work either.

It seems implausible that none of them power-up because they are all ‘broken’. I feel like there must be some secret I don’t know and haven’t been able to find.

Q1: Am I correct to expect this model of board to power-up when (only) a USB_C cable is plugged into it?

Q2: If not, why not? What do I need to do to make them work properly? Is there some pin or pins I need to pull low or high, or connect to each other.

Q3: Have YOU used this board successfully? On the crazy, off-chance, that I need a VERY unusual and special cable, PLEASE tell me what manufacturer and model I should buy.

This is pretty absurd. I’m on the verge of throwing them in the trash, but I REALLY like the screen on them. It would be VERY useful for several of my projects. So…

ANY HELP would be very much appreciated.

When it comes to computers, I have never gotten any of the usb-c port heltecs to power up with a usb-c cable connected to a computer.

Only with a usb-a to usb-c cable (IE usb-a into computer, usb-c into heltec).
or usb c->a->c jury rigging.
or hubs

This is consistent on 3 very different types of laptops (linux, mac, windows).

I believe it is related to the way the usb-c interface is done on these boards - it looks like they just pipe some of the pins to the cp2102, rather than have a totally functioning usb-c port.

I’m returning today to report that the problem is resolved, and as it turns out, exactly as you suggested. I still do NOT understand why none of the USB-C to USB-C cables work for this when they work fine for other USB-C devices that require the ‘data’ capability and, of course (though not necessarily, I suppose) the ‘power’ capability.

I found a USB_C female to USB-A Male cable and connected it to an apple USB-C male to USB-A female adapter, and I was SO surprised but thrilled that it did the trick.

BTW… before I thought to try the kludge, I had plugged a board into one of my solar battery charge manager modules – a DFRobot “Solar Power Manager 5V V1.1” and the board powered up. That put me onto the idea of trying the kludge. (Only in that it gave me confidence that the board was not ‘broken.’)

I had scoured the web before adding my original post and found no case mentioning anyone else experienced this. I’m almost as amazed that the problem exists in the first place.

Anyway, thanks very much for the advice. (Where were you over a month ago when I started down this rat hole? (;->)

Welcome to the USB-C hell.
All About USB-C: Manufacturer Sins


That was an interesting problem and question!

Likely, one those USC A/C adapters contains the two resistors (or even a chip) that tell a USB port to supply a certain amount of power, such as 3 amps.

USB3 over a USB C port is much faster and more capable than USB1 or USB2, with a sophisticated power delivery standard. It can provide up to 20 volts as I recall, while the old standard only does 5 volts. However, the trade-off is that it expects the device to be a little smart. The device needs to indicate what voltage and amperage it needs.

I just ran into the same problem. I am deploying a consumer device based on the Heltec Wireless Stick Lite V3. Telling users NOT to use a USB-C charger but to use a USB-A unit with a conversion cable is goofy, to put it mildly. I consider this a “bug”, not a “feature” and STRONGLY urge Heltec to get it fixed with a rev’d board.