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Outputs remains high when uploading new firmware via uart
Posted: Tue Dec 17, 2024 10:09 pm
by Baldhead
Hi,
Outputs (MCPWM controlled outputs) remains high when uploading new firmware via uart.
When uploading a new firmware via ota I haven't tested it, but I think there is no problem, perhaps, after the upload to the flash memory is completed, and the chip reset itself, the problem may appear (only in the reset phase).
I have two outputs controlled by MCPWM module that cannot be high( active ) at the same time.
Won't the "chip reset" not reset (logic low) the MCPWM output when the firmware is being uploaded into the ESP32-S3 ?
Re: Outputs remains high when uploading new firmware via uart
Posted: Fri Dec 20, 2024 1:47 am
by Baldhead
No one ?
Re: Outputs remains high when uploading new firmware via uart
Posted: Fri Dec 20, 2024 2:01 am
by boarchuz
Which pins are you using, and what does the ESP32S3 datasheet say about their state at/after reset? Do you have external pulldowns on them?
Re: Outputs remains high when uploading new firmware via uart
Posted: Fri Dec 20, 2024 2:32 am
by Baldhead
Which pins are you using, and what does the ESP32S3 datasheet say about their state at/after reset? Do you have external pulldowns on them?
Hi,
I am using 3 i/o's that are using mcpwm module( 39, 40 and 41).
I dont have pull down, but i think that the led of opto triac should not conduct with the esp32-s3 pin at high impedance when it is being flashed by uart.
I am thinking that when the mcpwm module output stay high, the chip reset dont reset the pin and the i/o stay high( but is a strange behavior if I'm correct).
Re: Outputs remains high when uploading new firmware via uart
Posted: Fri Dec 20, 2024 3:13 am
by boarchuz
Are you uploading via USB or UART? I'm not sure what reset type is triggered by USB, and I would be surprised if it was only CPU, but it's worth ruling out.
If you manually put the ESP32S3 into download mode via IO0 and EN (to ensure a full RTC reset and to ensure it stays in the bootloader where MCPWM is not yet initialised), what is the state of these pins? What if you manually hold EN low?
FWIW I think you should have external pulldowns on these pins to eliminate the possibility that the floating pins could cause sporadic/dim LED output.
Re: Outputs remains high when uploading new firmware via uart
Posted: Fri Dec 20, 2024 3:35 am
by Baldhead
Are you uploading via USB or UART? I'm not sure what reset type is triggered by USB, and I would be surprised if it was only CPU, but it's worth ruling out.
If you manually put the ESP32S3 into download mode via IO0 and EN (to ensure a full RTC reset and to ensure it stays in the bootloader where MCPWM is not yet initialised), what is the state of these pins? What if you manually hold EN low?
FWIW I think you should have external pulldowns on these pins to eliminate the possibility that the floating pins could cause sporadic/dim LED output.
I am using the same circuit that ESP32-S3-DevKitC-1.
Using cp2102n usb to uart bridge.
The chip flash are all ok
I am using visual studio code with espressif extension to flash the chip.
I flash the chip with mcpwm already working, because I need to power the board and the firmware automatically boots after powering on.