Schematic review needed

[salbdch]

Hello,

Attached file is part of my schematic.
Could you check it's no problem to Initial firmware download using UART?

schematic.jpg (159.53 KiB) Viewed 9465 times

P.S. EN pin and GPIO0 pin handling is mandatory for Initial firmware download?
If does, could you let me know how to handle those pins to ESP32 enter firmware download mode after boot?
Thanks,

[becorey]

You are missing a pull up resistor from RST to 3.3v. You just have a cap and a button, nothing will charge the cap.

10k R is typical, reference the esp32 hardware design guide.

You should base your design off existing hardware that is known to work, like the many esp32 dev boards that publish their schematic.

https://www.google.com/url?sa=t&source= ... KScKrVIgRg

If you are going with a 4 pin jtag connector, you need to press the reset and boot buttons manually. The common auto flash circuit that eliminates needing to press the button is used in conjunction with a uart bridge chip that outputs DTR and RTS signals. It looks like you're not using that so you can just use the buttons.

[salbdch]

Thanks a lot for information.

I have a power on/off slide switch on board so if reset pin is not mandatory for
firmware download, I prefer remove reset circuit.

I guess this procedure will be work for firmware download, could you check this out?
1. Pull-up GPIO0 port by short J14(jumper header)
2. Supply power to board
3. Make UART connection with PC and board using USBtoSerial dongle(connection would be Rx, Tx and Gnd)
4. firmware download to board using ESP32 Flash Download Tools
5. Power off the board
6. Pull-down GPIO0 by open J14
7. Supply power to board

Thanks in advance!

[ESP_Sprite]

Thanks a lot for information.

I have a power on/off slide switch on board so if reset pin is not mandatory for
firmware download, I prefer remove reset circuit.

The reset circuit is always mandatory; the ESP32 won't start up without a proper reset.

[salbdch]

Thanks,

Okay, will add resistor(10k) refer below schematic from esp32-wrover-e_esp32-wrover-ie_datasheet_en.pdf

11111.jpg (219.84 KiB) Viewed 9310 times

So, could you final check my procedure below would be correct?
Thanks in advance!

1. Pull-up GPIO0 port by short J14(jumper header)
2. Supply power to board
3. Push reset switch
4. Make UART connection with PC and board using USBtoSerial dongle(connection would be Rx, Tx and Gnd)
5. firmware download to board using ESP32 Flash Download Tools
6. Power off the board
7. Pull-down GPIO0 by open J14
8. Supply power to board

[ESP_Sprite]

That should work, assuming the rest of the GPIOs aren't connected to anything. If they are, be mindful of the other bootstrap pins that are there.

[salbdch]

Thanks a lot!

[salbdch]

Hello,

I got error while firmware download.
Could somebody let me know where should I check first?

[Questions]
I'm using same firmware download environment(PC, download tools) but I had succeed with esp-eye board
and now I'm trying with custom board using ESP32-WROVER_E module.
1. ESP-EYE's chip shows ESP32D0WDQ5 (revision 1) and my custom board shows ESP32D0WDQ5 (revision 3)
it can cause firmware download failure?
2. May Flash size different cause firmware download failure? (I guess flash size in ESP32-WROVER_E is also 4MB
but have to check for sure)
3. This link could help?
https://randomnerdtutorials.com/solved- ... et-header/

Code: Select all

esptool.py -p COM13 -b 460800 --before default_reset --after hard_reset --chip esp32 write_flash --flash_mode dio --flash_freq 80m --flash_size 4MB 0x8000 partition_table/partition-table.bin 0x1000 bootloader/bootloader.bin 0x10000 camera_web_server.bin
esptool.py v2.9-dev
Serial port COM13
Connecting........__
Chip is ESP32D0WDQ5 (revision 3)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 40:f5:20:5b:06:0c
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...

A fatal error occurred: Timed out waiting for packet content
esptool.py failed with exit code2

[becorey]

The R and C connected to EN are critical. They set the rise time of the voltage power up.

Can you confirm if you have 10K from 3.3V to EN, and (at least) 0.1uF from EN to GND?

[salbdch]

Hello, problem solved.

- I guess problem somewhat caused by limitation of my USB-to-UART dongle,
which connect my custom board and PC.
After I change download tool as "flash_download_tool_v3.8.5" and lower
UART baudrate as 115,200, it started work.
- ESP32-WROVER_E in my custom board turns out that have 8MB Flash inside.

Thanks for help anyway!
Regards,