Search found 14 matches

by devanl
Tue Apr 04, 2023 7:00 pm
Forum: ESP-IDF
Topic: 100% duty cycle with ledc on ESP32-S3
Replies: 0
Views: 759

100% duty cycle with ledc on ESP32-S3

I've been working with the ESP32-S3 and I noticed that when using the LEDC peripheral to generate a 100% duty cycle PWM signal (always on), if I use the maximum duty cycle value of (2^resolution - 1) as specified in the documentation (e.g 1023 for 10-bit resolution or 3 for 2-bit resolution), the re...
by devanl
Mon Feb 22, 2021 8:39 pm
Forum: ESP-IDF
Topic: rtc time doesn't seem to get updated from system time / ntp?
Replies: 3
Views: 3977

Re: rtc time doesn't seem to get updated from system time / ntp?

I forgot to add that the other drawback of using the RTC is that now your system time could drift substantially between NTP resyncs (IIRC, the RTC is rated for +/-5% frequency accuracy - the equivalent of 50000 ppm!).
by devanl
Sat Feb 20, 2021 5:04 am
Forum: ESP-IDF
Topic: rtc time doesn't seem to get updated from system time / ntp?
Replies: 3
Views: 3977

Re: rtc time doesn't seem to get updated from system time / ntp?

Hi, I've run into this problem before. As you guessed, the fundamental issue is that by default, the system uses a different timer than the RTC to keep track of system time and those two clocks have very different accuracy specs (ironically, the system timer is more accurate than the RTC, but to be ...
by devanl
Fri Aug 21, 2020 4:29 am
Forum: ESP-IDF
Topic: esp-idf git tree becomes dirty after git pull latest code
Replies: 5
Views: 5081

Re: esp-idf git tree becomes dirty after git pull latest code

So, depending on how far you jumped when migrating to master, in some cases, the submodule dependencies of another submodule may have changed and left behind a submodule directory whose contents git suddenly no longer is tracking as a submodule. That can lead to the behavior you see where you have p...
by devanl
Tue Aug 04, 2020 5:34 am
Forum: ESP-IDF
Topic: UART bootloader security
Replies: 2
Views: 3651

Re: UART bootloader security

Hi Angus,

Thanks for the explanation. Knowing more about how the security features work makes me a bit more comfortable making some of the tradeoffs between security and other requirements.
by devanl
Mon Aug 03, 2020 9:11 pm
Forum: ESP-IDF
Topic: UART bootloader security
Replies: 2
Views: 3651

UART bootloader security

Is the ROM serial bootloader for the ESP32 rev 3 reasonably secure if left enabled? That is, if I set the efuses as follows: Efuse Name Description Value R/W FLASH_CRYPT_CNT Flash encryption mode counter 127 R/- UART_DOWNLOAD_DIS Disable UART download mode False R/- FLASH_CRYPT_CONFIG Flash encrypti...
by devanl
Mon Jun 15, 2020 8:29 pm
Forum: General Discussion
Topic: esp32 s2 DFU update
Replies: 9
Views: 10807

Re: esp32 s2 DFU update

Hi, author of the webdfu proof-of-concept code here. I just want to second rainman's suggestion to add a WCID descriptor to the ROM DFU bootloader so that Windows will automatically install a generic WinUSB driver. This would be a huge step forward in usability for browser based IDEs and demos that ...
by devanl
Wed Apr 15, 2020 11:07 pm
Forum: ESP-IDF
Topic: AWS S3 - root certificate changing
Replies: 4
Views: 10102

Re: AWS S3 - root certificate changing

I don't have any experience with an actual certificate changeover, but my experience with concatenated PEM files and the existing AWS / ESP-IDF library code is that they seem to work fine, so I would expect that you could put both certificates in a single concatenated PEM file and you would be able ...
by devanl
Thu Mar 12, 2020 9:39 pm
Forum: ESP-IDF
Topic: anyone using Ubuntu under Windows 10?
Replies: 7
Views: 8243

Re: anyone using Ubuntu under Windows 10?

I've tried setting different speeds in the menuconfig Serial Flasher Config-> 'idf.py monitor' baud rate (921600 bps) ---> No matter what I set it to, when the program goes to flash the board, it still reports as 460800. Hmm, I'm not sure what would cause that issue. Fow now, maybe just manually pa...
by devanl
Thu Mar 12, 2020 3:57 pm
Forum: ESP-IDF
Topic: anyone using Ubuntu under Windows 10?
Replies: 7
Views: 8243

Re: anyone using Ubuntu under Windows 10?

I do a lot of development with Ubuntu under WSL on Windows 10. I've since switched to using openocd (running under Windows) to flash my boards, but when I was still using the bootloader, I ran into a similar issue. I found the discussion on a GitHub issue helpful - oddly enough, certain baudrates wo...