Search found 8 matches

by edigi32
Tue Jun 18, 2019 1:46 pm
Forum: ESP-IDF
Topic: Reduce external interrupt latency
Replies: 15
Views: 26728

Re: Reduce external interrupt latency

Unfortunatelly what you've described here as a solution is not a real solution except maybe for the simplest cases. Don't misunderstand me, I have stumbled to this issue as well, and asked for solution. https://esp32.com/viewtopic.php?t=9418 What you describe here (if I understand it correctly) is b...
by edigi32
Tue Feb 26, 2019 9:57 am
Forum: ESP32 Arduino
Topic: How to improve interrupt latency with Arduino/C
Replies: 1
Views: 4142

How to improve interrupt latency with Arduino/C

After having issues with interrupt latency I've checked an older thread where it's described that interrupt latency with C is around 2us. Is there a way (if possible code please) to improve it with some kind of in-line assembly (without RTOS change)? My ISR routines are very simple e.g. capturing PC...
by edigi32
Tue Feb 26, 2019 9:43 am
Forum: General Discussion
Topic: What would you like to see in The Next Chip?
Replies: 426
Views: 785841

Re: What would you like to see in The Next Chip?

- 32 bit PCNT counter (with capture possibility)
- better interrupt latency (even when using C/Arduino)
- better ADC (less noisy conversion, better linearity)
by edigi32
Fri Oct 26, 2018 7:22 am
Forum: ESP-IDF
Topic: My long path to configuring the RMT and PCNT to share GPIO
Replies: 14
Views: 19283

Re: My long path to configuring the RMT and PCNT to share GPIO

It is possible to use the PCNT without any control pin if -1 is assigned to control GPIO at initialization time. Thus: pcnt_config.ctrl_gpio_num = -1; Via this and my earlier sample it is possible that counting is started/stopped entirely from SW (in my case from interrupt code, connecting the contr...
by edigi32
Tue Oct 16, 2018 12:56 pm
Forum: ESP-IDF
Topic: My long path to configuring the RMT and PCNT to share GPIO
Replies: 14
Views: 19283

Re: My long path to configuring the RMT and PCNT to share GPIO

Sorry for hijacking this thread with a question that somewhat still relates to it. So I'd like to control from ISR when PCNT counting is started/stopped (without any control pin assigned to this). That is i'd like to connect the input signal of 41 (pcnt_ctrl_ch0_in0; PCNT unit 0, channel 0) to GPIO_...
by edigi32
Wed Oct 10, 2018 1:12 pm
Forum: General Discussion
Topic: Using ESP32 for precise frequency measurement
Replies: 3
Views: 8407

Re: Using ESP32 for precise frequency measurement

One more question related to MCPWM. Would it be possible to force a one shot capture mode? So what I mean that after the mcpwm_capture_enable is called and a single capture happens, ESP32 by its own would stop capturing of the given capture signal (counter still counting in the background, only the ...
by edigi32
Fri Oct 05, 2018 8:51 am
Forum: General Discussion
Topic: Using ESP32 for precise frequency measurement
Replies: 3
Views: 8407

Re: Using ESP32 for precise frequency measurement

External divider (prescaler) is no issue and in fact I use it for higher frequency signals. However I've tried to build reciprocal counter also where instead of RMT gating MCPWM capture is used (and capture interrupt with very tight timing to make gating synchronous with the signal to be measured) a...
by edigi32
Fri Oct 05, 2018 7:16 am
Forum: General Discussion
Topic: Using ESP32 for precise frequency measurement
Replies: 3
Views: 8407

Using ESP32 for precise frequency measurement

I'm building with ESP32 a high precision frequency meter. Under high precision I mean 7-8 digits. Later on I plan to use Neo-7N GPS receiver to calibrate and improve precision (via 1pps output; it works, tested already). I've used RMT to generate gating signal and PCNT to count the signal to be meas...