ESP32 Forum

Can anyone support the issues as explained below?

Breakout board PCB with ESP32 WROOM 32D to just test the serial connections and flashing the esp32 wroom module.
The Schematic has been attached.
USB to TTL - CP2102 -Image as attached.

Issues--
I'm not able to flash the module as it was showing flash not detecting error initially but after then nothing just a question mark.
It shows connecting ....../....../ like logs but when I pressed reset/en then again nothing happens.

Does my schematics correct?

Tried--
1. Just keep the IO0 low during the flashing mode and press the reset button but nothing happens.
But strange happens like when I connect IO0 to ground then USB TTL shows TX led high and when I press Reset button on ESP32 RX led also becomes high but nothing happens. It seems to be like initially that keeping IO0 low serial monitor on Arduino ide shows flash error but when I connect it to ground then nothing on the serial monitor.

2. Checked all pins for continuity.
3. Pin 6 to 11 - No connections
4. perfect voltage - 3.2v

Do I need to change the schematics or the flash is broken or am I doing something wrong in flashing?

Please suggest & thanks for your help in advanace.

Which supply pin do you really connect? I see in the image is 5V? And do you know if power supply current is enough of this serial board? Could you see logs with UART0?

Thanks for reply.
I forgot to mention one part of schematic where iam using ams1117 to convwet from 5v to 3.3v.
So thats why connected to 5v pin of USB.
Current and voltage is perfectly matched as per esp32 requirement, but i didnot chk the uart0 logs.
How to chk those logs ?
But i chkd the board with usb ttl to a serial software where it shows the rx[00] [ff]is receiving something when IO0 is connected and disconnected to ground pin initially.
But now nothing.

Here is the PCB prorotype board with ESP32 WROOM 32D module and will be use with Raspberey PI after this.
But somehow , i think we have received either corrupted flash or module. We have tried every possible way to correct it but noway to found the failure. Is there any other way to find the root cause of it?
Hereby attached is the PCB prototype board images for reference.
Thanks in advance for your support.

...U4 is not in your schematic? Can you send the *actual* schematic you're having issues with?

I do have issues in ESP32 schematics as U4 is just serial ic not linked with ESP32 module.

ESP_Sprite wrote: ↑

Sat Oct 09, 2021 6:09 am

...U4 is not in your schematic? Can you send the *actual* schematic you're having issues with?

U4 is just serial chip and iam directly connecting 3.3v except 5 v. Weird behaviour like now sometime it start flashing and then stop at 44% and then fatal error no packet header. Then after that again continuousely showing fatal error.
When i keep the module for for few hrs. Without power then again it shows 44% flash and then fatal error. Reset and enable logic is working.
Sometimes shows flash read error 1000.
Tried almost everything available on internet.

Is this a schematic or design error or module error. Module is esp32 dowd revision -1.
Sometimes it shows watchdog timer reset and spi fast flash mode.

Can anyone suggest on it?

I can't tell anything more from half schematics and pictures that seem to be made in different setups. I'd suggest you triple-check the power supply, though; that's the thing that most consistently seems to give people issues.

ESP_Sprite wrote: ↑

Thu Oct 14, 2021 6:56 am

I can't tell anything more from half schematics and pictures that seem to be made in different setups. I'd suggest you triple-check the power supply, though; that's the thing that most consistently seems to give people issues.

Thanks for your reply.
Tried many things, but just nothing happened. The module worked for few minutes again after I kept it for a few hrs.
It detected flash 16MB & then download successful too, but after running the code for 10 minutes it showed 'flash error 1000' and after that again not detecting the flash and time out error.
Below is the schematics attached. Power is 3.10v on all the required pins.

One more strange thing happened that when I applied 3.3v through USB TTL, then the AMS1117 3.3V regulator shows 2.5v on 5v input of the regulator.

Plz suggest -
Doe's schematics have an issue?,,, Chip has a flash issue,,,, or one more thing on the PCB board I used (3.3v,uart0, GPIO0, GND) on 1.27 mm dia holes. which should be at least 2.54mm.

Below is the schematics attached. Power is 3.10v on all the required pins.

Check your power supply. An AMS1117 is not supposed to output as low as 3.1V. You should see a healthy 3.3V (or very close to it) on all relevant pins.

One more strange thing happened that when I applied 3.3v through USB TTL, then the AMS1117 3.3V regulator shows 2.5v on 5v input of the regulator

An LDO generally isn't specified wrt behaviour when you feed its input only, so this is kind-of expected. Also, don't use the 3.3V from your USB serial converter; it is not powerful enough. Did I mention to use a good supply already?

Generally, get a power supply that you are absolutely 100% sure can provide 5V or 3.3V at at least 500mA. Feed that into either the AMS1117 in case of 5V, or directly into the ESP32 in case of 3.3V. Use wires that are thick enough. If there's an USB cable involved, make 100% sure it's good quality: you have no idea how many USB cables have shitty copper-plated aluminium wires inside.