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Re: New ESP32 Board Bootloader
Posted: Mon Feb 08, 2021 2:04 pm
by lannocm
That sounds promising but my board doesn't have pins, as such. Here is the physical layout and the schematic for the ESP32. What should I be doing and how?
Thanks very much.
Re: New ESP32 Board Bootloader
Posted: Mon Feb 08, 2021 3:44 pm
by WiFive
You have to press the reset button while shorting JP1
Re: New ESP32 Board Bootloader
Posted: Mon Feb 08, 2021 8:11 pm
by lannocm
So, since posting the last post, I've done a bit of research and had a further look at the schematic from the designer. According to the esp32 documentation, it looks like there are a couple of options for getting the board in to boot mode. One of which is to send GPIO0 to ground. When I looked at the pcb diagram again, I could see that there is a jumper to set to allow that to happen.
However, I've tried it in a few different ways, for example with the reset button, but it is still timing out. Anyone have any ideas what to try next or which combination to try?
Many thanks
Re: New ESP32 Board Bootloader
Posted: Tue Feb 09, 2021 2:43 am
by Sprite
Try starting a serial terminal at 115200 baud on the port the ESP32 is connected to. If everything is OK, you should see some text on there when you reset the ESP32, and if you try to put it into download mode you should see a different text.
Re: New ESP32 Board Bootloader
Posted: Tue Feb 09, 2021 11:34 am
by lannocm
Nada, zip, nothing!
When the ESP32 is connected to the serial port (I've tried PuTTY and Arduino), there is no text whatsoever, either after pressing the reset button or closing the jumper and pressing the reset button.
At the moment the power supply is the USB from the pc, which, I think, is 5v. Does it need to be 3.3v? Or could it be an issue with the cable itself? I have tried several, some of which register as a COM port and some don't. Does registering as a COM port indicate that the Tx and Rx are connected to the board?

Re: New ESP32 Board Bootloader
Posted: Tue Feb 09, 2021 4:29 pm
by WiFive
Does registering as a COM port indicate that the Tx and Rx are connected to the board?
It indicates the PC is connected to the ft232 chip, beyond that nothing. We don't know anything about the power supply since you didn't post the full schematic. You are getting into hardware debugging zone which means probing the board for expected voltages and signals using a meter, scope or logic analyzer.
Re: New ESP32 Board Bootloader
Posted: Tue Feb 09, 2021 6:25 pm
by lannocm
Hmm... I have a meter, so I can check voltages. I don't have a scope and I don't really know what a logic analyser is.
In the meantime, here is the full schematic.
Thanks for your continuing help.
Re: New ESP32 Board Bootloader
Posted: Tue Feb 09, 2021 8:55 pm
by WiFive
Check for 3.3v, make sure the switch is on, and try with a battery connected. It looks like there might be a mistake connecting vbat+ to the vreg instead of vbat_out
Re: New ESP32 Board Bootloader
Posted: Tue Feb 09, 2021 9:05 pm
by lannocm
Hi, can you explain a bit more please? Are you referring to EN1 on the battery charging circuit? Where is VREG? What is VREG?
Thanks
Re: New ESP32 Board Bootloader
Posted: Tue Feb 09, 2021 10:24 pm
by WiFive
u1 the voltage regulator
Also there is no flash chip on the schematic so are you using esp32-u4wdh?