missing sdkconfig.defaults, tuned timing coefs

[tom-van]

Hi Brian,
thanks again for an interesting project!

I thought about reasons of missing CONFIG_LWIP_SO_RCVBUF=y in any new config. I'm certainly not an ESP IDF guru but it looks that creating sdkconfig.defaults file containing at least:

CONFIG_LWIP_SO_RCVBUF=y

could help to get proper config immediately after idf.py set-target
I would also recommend compiler optimisation setting to avoid inexperienced users to run the slow non-optimised version

CONFIG_COMPILER_OPTIMIZATION_PERF=y
CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_DISABLE=y

and also pinning WiFi task to Core 1 - it makes no harm on single core ESP32 variants, simply it's not used

CONFIG_ESP_WIFI_TASK_PINNED_TO_CORE_1=y

in sdkconfig.defaults

I used a logic analyser to fine tune the timing coefs on ESP32 with the config settings above.

CONFIG_ESP_DAP_IO_PORT_WRITE_CYCLES=12
CONFIG_ESP_DAP_DELAY_SLOW_CYCLES=11

gives good frequency precision at low speed and acceptable precision at high speeds. This could go to sdkconfig.defaults.esp32 file.

I have C6 and C3 boards so I can tune timing on them as my free time permits. Unfortunately I don`t have any S3 board - although I would guess the timing could be similar to the vanilla ESP32.

[tom-van]

For ESP32C6, CONFIG_COMPILER_OPTIMIZATION_PERF=y, CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_DISABLE=y
the coef

CONFIG_ESP_DAP_DELAY_SLOW_CYCLES=5

is correct, the second one should be

CONFIG_ESP_DAP_IO_PORT_WRITE_CYCLES=39

[bkuschak]

Hi Tom, thanks for your suggestions! I'm sorry, I missed seeing these comments earlier. I'll try to get these changes integrated soon.