Search found 15 matches
- Thu Sep 09, 2021 3:24 pm
- Forum: General Discussion
- Topic: himem page change delays isr
- Replies: 4
- Views: 2984
Re: himem page change delays isr
To give a rough estimate. the delay due to cache reload is about 3 to 4 ms. Is that expected?
- Thu Sep 09, 2021 10:24 am
- Forum: General Discussion
- Topic: himem page change delays isr
- Replies: 4
- Views: 2984
Re: himem page change delays isr
@ESP_Sprite Thank you for your answer with the explanation about the cache being flushed. I indeed think that this is actually impacting my isr. Any chance, that I can change my isr in such a way that there is no impacted by the cache having been flushed? Did I understand correctly, that when placin...
- Thu Sep 09, 2021 7:05 am
- Forum: General Discussion
- Topic: himem page change delays isr
- Replies: 4
- Views: 2984
himem page change delays isr
I just observed, that when changing the page in the himem api with esp_himem_unmap and esp_himem_map these two calls influence the timing of an isr which is triggered by a pin level change. What is going on here? Actually I'd like to understand what is going on and probably someone can shed some mor...
- Fri Feb 12, 2021 9:25 am
- Forum: General Discussion
- Topic: How do you setup a UART Rx interrupt on a ESP32-S2?
- Replies: 5
- Views: 14154
Re: How do you setup a UART Rx interrupt on a ESP32-S2?
Having spent a night fithing with this. Here is the key:
You can not directly access the UART0.fifo.rw_byte on esp32s2 but have to use READ_PERI_REG(UART_FIFO_AHB_REG(0))
Hope this helps
You can not directly access the UART0.fifo.rw_byte on esp32s2 but have to use READ_PERI_REG(UART_FIFO_AHB_REG(0))
Hope this helps
- Tue Jan 12, 2021 12:06 am
- Forum: General Discussion
- Topic: RFC: ESP32_WIFI_CACHE_TX_BUFFER_NUM
- Replies: 0
- Views: 2034
RFC: ESP32_WIFI_CACHE_TX_BUFFER_NUM
This got introduced here and I do not understand the behaviour: https://github.com/espressif/esp-idf/commit/368d623e1af2a43a08a5ec1b5983a75b70ca4071 If SPIRAM is available but not for use by malloc this change will make internal ram very tight. So, I tried to manually setting the number of caches to...
- Mon Nov 02, 2020 3:51 pm
- Forum: General Discussion
- Topic: gettimeofday from isr crashes
- Replies: 3
- Views: 4958
Re: gettimeofday from isr crashes
hey mikemoy well, I don't care if the answers I am getting are rude or not as long as it helps me to get forward... So, let me rephrase the question as I don't see how the example you linked would help me: The original question I have: How can I get the exact timeofday of a pin (gpio interrupt) chan...
- Tue Oct 27, 2020 6:30 pm
- Forum: General Discussion
- Topic: gettimeofday from isr crashes
- Replies: 3
- Views: 4958
Re: gettimeofday from isr crashes
Well this is quite an old question. But I still could not figure out how to do this in a nontrivial way. I do use the timer to get a timestamp in the isr and assemble the time later by using the timer and gettimeofday function. By subtracting the difference in the timer value from the gettimeofday I...
- Wed Aug 26, 2020 6:07 am
- Forum: General Discussion
- Topic: Time sync over wifi
- Replies: 1
- Views: 3245
Re: Time sync over wifi
Just in case somebody is visiting this:
since a few days there is a new function in the wlan api (only esp-idf 4.2 ):
esp_wifi_get_tsf_time
which seems to be made for the task at hand.
since a few days there is a new function in the wlan api (only esp-idf 4.2 ):
esp_wifi_get_tsf_time
which seems to be made for the task at hand.
- Sat Jul 04, 2020 1:29 pm
- Forum: General Discussion
- Topic: Time sync over wifi
- Replies: 1
- Views: 3245
Time sync over wifi
I have multiple esp32 which are connected over wlan with an ap also running on a esp32. I'd like to sync their clock to an accuracy of about 1ms. There are multiple things which I could imagine that would work: * use wlan beacons The question here is if there is access to the beacon event or if this...
- Fri May 29, 2020 3:26 pm
- Forum: General Discussion
- Topic: gettimeofday from isr crashes
- Replies: 3
- Views: 4958
gettimeofday from isr crashes
How to get the timeofday from an isr? If I do use gettimeofday from isr it crashes if the application is also executing gettimeofday because the lock is acquired already by the application. Here is the relevant traceback: 0x40097ba0: invoke_abort at panic.c:? 0x40097f11: abort at ??:? 0x4008685b: lo...