Search found 8 matches

by xiaolaba
Thu Jul 04, 2024 12:41 am
Forum: 硬件问题讨论
Topic: 請問 ledc 可以產生 4組 2MHZ ~ 8MHZ 的訊號嗎
Replies: 0
Views: 134

請問 ledc 可以產生 4組 2MHZ ~ 8MHZ 的訊號嗎

首先感謝各路大俠指點.
目標,
每個IO輸出 25% 的 duty cycle, 固定的
4個IO輪流輸出,
頻率範圍大約 2MHz ~ 8MHz,
時序的示意圖大概如下,

_|~|_____|~|______
___|~|_____|~|______
_____|~|_____|~|______
_______|~|_____|~|______
by xiaolaba
Wed Mar 22, 2023 12:44 pm
Forum: 硬件问题讨论
Topic: boot_comm: can't run on lower chip revision, expected 1, found 3
Replies: 2
Views: 2239

boot_comm: can't run on lower chip revision, expected 1, found 3

請問有何原因呢 Message (Enter to send message to 'ESP32 Dev Module' on 'COM7') New Line 115200 baud oad:0x3fff0034,len:7488 ho 0 tail 12 room 4 load:0x40078000,len:13904 load:0x40080400,len:5296 entry 0x40080710 [0;32mI (31) boot: ESP-IDF v4.2.1 2nd stage bootloader[0m [0;32mI (31) boot: compile time 09:40...
by xiaolaba
Sat Feb 18, 2023 2:57 am
Forum: ESP32 Arduino
Topic: Best Frequency Meter ever made with ESP32 - awesome!
Replies: 80
Views: 103783

Re: Best Frequency Meter ever made with ESP32 - awesome!

Hi Xiaolab, If you don't have another frequency counter or oscilloscope frequency meter, you won't be able to calibrate because you won't have a reference measurement. The ESP32 oscillator has some limitations in the resolution of the generated signal adjustment. So you can't rely on that signal al...
by xiaolaba
Tue Feb 14, 2023 1:58 pm
Forum: ESP32 Arduino
Topic: Best Frequency Meter ever made with ESP32 - awesome!
Replies: 80
Views: 103783

Re: Best Frequency Meter ever made with ESP32 - awesome!

Hi xialaba, As I mentioned in the tutorial, the frequency measurement can be calibrated with another frequency meter for calibration! You can calibrate, changing the variable: uint32_t sample_time = 1000000; Regards Gustavo Murta Thanks Gustavo, I read your blog and trying to understand more about ...
by xiaolaba
Fri Feb 10, 2023 4:36 am
Forum: ESP32 Arduino
Topic: Best Frequency Meter ever made with ESP32 - awesome!
Replies: 80
Views: 103783

Re: Best Frequency Meter ever made with ESP32 - awesome!

hi, our prototype built show a littel difference, the default 12543Hz showing 12539Hz. 20MHZ is showing 20,000,156 HZ, it saying offset 156Hz then half each step and offest does the same, till 10KHz only an old 20MHZ CRT scope was used to counter check some spots, it is ok, but would like to underst...
by xiaolaba
Wed Sep 30, 2020 1:23 am
Forum: ESP-IDF
Topic: ESP-IDF v4.1, cpu_start.c:551: undefined reference to `app_main'
Replies: 5
Views: 7113

Re: ESP-IDF v4.1, cpu_start.c:551: undefined reference to `app_main'

thanks for your help. there were three options experimented to the builds, moved CMakeLists.txt back and forth, one folder at a time existed only, or put them all. ESP32_MP3_Decoder\main\CMakeLists.txt ESP32_MP3_Decoder\CMakeLists.txt It does not matter where we put the CMakeLists.txt, still the sam...
by xiaolaba
Tue Sep 29, 2020 4:20 am
Forum: ESP-IDF
Topic: ESP-IDF v4.1, cpu_start.c:551: undefined reference to `app_main'
Replies: 5
Views: 7113

Re: ESP-IDF v4.1, cpu_start.c:551: undefined reference to `app_main'

yes, your are absolute right. that was one of trial and error to see whether be able port the project and hopefully to remove the compilation error, but it turned out the same error produced by linker.
by xiaolaba
Sat Sep 26, 2020 7:28 am
Forum: ESP-IDF
Topic: ESP-IDF v4.1, cpu_start.c:551: undefined reference to `app_main'
Replies: 5
Views: 7113

ESP-IDF v4.1, cpu_start.c:551: undefined reference to `app_main'

hi, need help there to understand cause and looking for solution. The hello_world build under ESP-IDF v4.1 has been done and fine, so we know the build tool chain and setup has been done perfectly. we has try to build the project ESP32_MP3_Decoder, failed and log shows following [Codebox] c:/users/u...