Search found 17 matches

by scotthauck
Wed Jan 22, 2020 10:56 pm
Forum: ESP32 Arduino
Topic: Question re: sub-microsecond timing, performance tuning
Replies: 6
Views: 1037

Re: Question re: sub-microsecond timing, performance tuning

Seven in one case, three in another.
by scotthauck
Sat Jan 18, 2020 9:11 pm
Forum: ESP32 Arduino
Topic: Question re: sub-microsecond timing, performance tuning
Replies: 6
Views: 1037

Re: Question re: sub-microsecond timing, performance tuning

Using lots of steppers, so nothing pre-built I could find. Through disassembly and hunting around found a few of the issues: xthal_get_ccount() is a subroutine call for a single assembly instruction - better to do the assembly equivalent to avoid call overhead. XT_CLOCK_FREQ is also a subroutine cal...
by scotthauck
Fri Jan 17, 2020 10:25 pm
Forum: ESP32 Arduino
Topic: Disassembly process?
Replies: 2
Views: 955

Re: Disassembly process?

Got disassembly going, via objdump, on my Windows 10 box for Arduino compiles. Hope this helps other folks. Install the ESP-IDF tools (if you haven't already). See the homepage for how. Find the place where the Arduino tools do the build: https://www.kanda.com/blog/microcontrollers/avr-microcontroll...
by scotthauck
Fri Jan 17, 2020 6:28 am
Forum: ESP32 Arduino
Topic: Disassembly process?
Replies: 2
Views: 955

Re: Disassembly process?

Well, I at least found the object files.

C:\Documents and Settings\<user name>\Local Settings\Temp\arduino_build_<a number for that build>\sketch

Looks like it is time to install the ESP tools and figure out how to use objdump...
by scotthauck
Wed Jan 15, 2020 11:29 pm
Forum: ESP32 Arduino
Topic: Disassembly process?
Replies: 2
Views: 955

Disassembly process?

Any suggestions on how to get a disassembly of code for ESP32 under Arduino? Specifically:
(1) Any pointers to a disassembler that people like? I'm developing on a Windows 10 box.
(2) Any pointers to where the executables are stored when you are using the Arduino IDE?

Thanks in advance.
by scotthauck
Tue Jan 14, 2020 1:04 am
Forum: ESP32 Arduino
Topic: Question re: sub-microsecond timing, performance tuning
Replies: 6
Views: 1037

Question re: sub-microsecond timing, performance tuning

I'm working on code to interface to a motor controller with 1us and 200ns setup and hold time requirements. If I do timings via micros(), I'll be wasting a noticeable amount of time (probably 2-3 microseconds due to resolution issues), so decided to roll an alternative using ccount. But, the routine...
by scotthauck
Fri Aug 09, 2019 2:40 am
Forum: ESP32 Arduino
Topic: Working with pre-release versions?
Replies: 0
Views: 703

Working with pre-release versions?

Okay, just had my second experience where digging through the pre-release versions of the ESP32 arduino core code turned up bug fixes that got me past blocking issues. So, my questions: (1) What's the right way to grab pre-release versions of the code? Right now I've been manually applying specific ...
by scotthauck
Fri Aug 09, 2019 2:33 am
Forum: ESP32 Arduino
Topic: Debugging stalled threads - volatile variables, others?
Replies: 3
Views: 818

Re: Debugging stalled threads - volatile variables, others?

FYI, applying that patch seems to have fixed my problem - thanks!
by scotthauck
Fri Aug 09, 2019 1:31 am
Forum: ESP32 Arduino
Topic: Debugging stalled threads - volatile variables, others?
Replies: 3
Views: 818

Re: Debugging stalled threads - volatile variables, others?

Thanks for the pointer. I am using AsyncUDP, but I'll try updating to the newest version - did grab the ESP32 support package just in the last few weeks, but perhaps the separate library may be newer. Serial.print as a timing issue - when the system locks up for me, it locks up forever afterwards - ...
by scotthauck
Wed Aug 07, 2019 8:55 pm
Forum: ESP32 Arduino
Topic: Debugging stalled threads - volatile variables, others?
Replies: 3
Views: 818

Debugging stalled threads - volatile variables, others?

Quick questions: any good way to find out WHERE a thread is stalling out, particularly a packet event handler for Wifi? My current plan is to put in lots of writes to a volatile variable in the code that is stalling, and have the main loop (which is still running) print out that variable's value per...

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