Search found 294 matches

by jcsbanks
Sun Jun 17, 2018 9:36 pm
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105919

Re: About the CAN controller.

I have a dramatic performance improvement to share that reduces latency between receiving a frame and transmitting a response from around several milliseconds down to <80us (most of the time <10us which is the resolution with which my Kvaser CAN device can measure). It doesn't do too much in the CAN...
by jcsbanks
Wed Jun 06, 2018 2:02 pm
Forum: ESP32 IDF
Topic: esp_wifi_connect() does not yield to other tasks?
Replies: 5
Views: 1771

Re: esp_wifi_connect() does not yield to other tasks?

Thanks ESP_Sprite. Very helpful, will investigate along these lines.

Yes I do use floats in the RMT task that normally runs every 5ms.

The RMT task can be starved for at least 400ms depending on frequency.

If one core is writing to flash, can the other core still run normally?
by jcsbanks
Tue Jun 05, 2018 5:15 pm
Forum: ESP32 IDF
Topic: Separate user code from system code to decrease ota binary size
Replies: 9
Views: 2760

Re: Separate user code from system code to decrease ota binary size

Interesting. Do you also pass parameters to the functions?
by jcsbanks
Tue Jun 05, 2018 4:53 pm
Forum: ESP32 IDF
Topic: Separate user code from system code to decrease ota binary size
Replies: 9
Views: 2760

Re: Separate user code from system code to decrease ota binary size

ISWYM. Some of my build steps use symbol information from other parts of the build that are in a .map file. Works well as long as you keep the binary and the map file together. Have you found a better or alternative way to automatically populate your function pointer table?
by jcsbanks
Tue Jun 05, 2018 4:08 pm
Forum: ESP32 IDF
Topic: Separate user code from system code to decrease ota binary size
Replies: 9
Views: 2760

Re: Separate user code from system code to decrease ota binary size

I haven't started with partitions/OTA on ESP32 yet, but do a lot of related tricks on automotive engine control units running Tricore microcontrollers using GNU C and linker scripts with bits of assembly where necessary to bypass, replace or augment existing compiled functions, including calling exi...
by jcsbanks
Tue Jun 05, 2018 11:26 am
Forum: ESP32 IDF
Topic: esp_wifi_connect() does not yield to other tasks?
Replies: 5
Views: 1771

Re: esp_wifi_connect() does not yield to other tasks?

Bit more context, in this case with the 5 second delay between esp_wifi_connect and starting task_RMT_Rx: void app_main() { nvs_flash_init(); tcpip_adapter_init(); ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) ); wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT(); ESP_ERROR_CHECK( esp_w...
by jcsbanks
Tue Jun 05, 2018 11:05 am
Forum: ESP32 IDF
Topic: esp_wifi_connect() does not yield to other tasks?
Replies: 5
Views: 1771

esp_wifi_connect() does not yield to other tasks?

I have a task called task_RMT_Rx that regularly flushes an RMT receive buffer that records pulse width hi/lo pairs. Because my hi/lo pairs are continuous, I have to do this as no interrupt can be called. If task_RMT_Rx is not run often enough, the RMT buffer overflows and I have to do a rather clums...
by jcsbanks
Sun Jun 03, 2018 8:42 am
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105919

Re: About the CAN controller.

ESP32 is little endian but most vehicles I have dealt with put 16 bit values big endian in CAN frames even if their CPU is little endian. 12 bit is also common for torque values.
by jcsbanks
Mon Apr 30, 2018 12:19 pm
Forum: Hardware
Topic: Need 16 MB Flash supported ESP32-WROVER module
Replies: 10
Views: 3263

Re: Need 16 MB Flash supported ESP32-WROVER module

Analog Lamb said they could not do 1000 qty and also didn't have FCC/CE testing/markings for 16MB WROOM, I did not ask about WROVER.
by jcsbanks
Sat Apr 28, 2018 5:09 pm
Forum: Hardware
Topic: About the CAN controller.
Replies: 173
Views: 105919

Re: About the CAN controller.

Glad you fixed. Looks like it needs some C preprocessor conditionals.

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