Does the 24M or 26M crystal are suit ESP32？

[Smartisan]

Hi：
we are now use 40M crystal for our ESP32,it download flash and can run well,also it can connect the soft AP. According to the
document，it can also use 24M and 26M crystal ,we want to save the power and battery,so we use the 24M and 26M crystal, but the download is well,to be sad the 24M and 26M crystal can not run well,it can not connect the soft AP.please tell me why?THX

[ESP_igrr]

I think only the 26MHz crystal is supported now, 24MHz could be supported in the future if there is demand for that.

Please try selecting 26MHz in menuconfig explicitly, under "Component config", "ESP32-specific", "Main XTAL frequency".
By default the system is configured to autodetect XTAL frequency, maybe there is some problem with that.

[Smartisan]

Hi,why the tech document said it suit 24M 26M and 40M crystal,but now you think only suit 26M and 40M.
Now i post the picture,i want to ask where "Main XTAL frequency",could you please find it to me.We use the
IDF rc 2.0.
Thank you a lot .
The picture is in the attachments.

IMG_20170520_133632R.jpg (4.18 MiB) Viewed 14033 times

[ESP_igrr]

The chip does support 24MHz, and the software can be made to support 24MHz as well. However this isn't yet implemented because there wasn't sufficient demand for this. Your interest is noted and I will check about prioritizing this feature for the next release.

Choice between 26 and 40 MHz in menuconfig was implemented after 2.0 release. So in v2.0-rc1, v2.0-rc2, and v2.0 this feature is not available. You can get it if you use recent git version of ESP-IDF. Alternatively, if you wait a couple of weeks, it will be released in v2.1.

Is there a specific reason why you need to use a pre-release version?

[Smartisan]

But why your tech document said that the esp32 support the24M 26M 40M.I think the tech document is correct and had be implemented.Now you said the 24M and 26M has yet implemented ,are you kidding? If the 24m and 26M has not implemented why your
tech document said the chip and software support them.
We had done a lot for the ESP32 according to your tech documents,but now we can't use the 24m and 26m.
I want to ask which verson IDF support the under "Component config", "ESP32-specific", "Main XTAL frequency".
By default the system is configured to autodetect XTAL frequency, maybe there is some problem with that.
We may not have time waiting for your next IDF verson.

[ESP_igrr]

The explicit choice of XTAL frequency has been added to menuconfig recently, and if you use latest git version of ESP-IDF, the option should be there.
26 MHz should work with older versions with autodetect. Can you print out the contents of RTC_CNTL_STORE4_REG and RTC_CNTL_STORE5_REG and post them here? That may give a clue why 26MHz xtal doesn't work.

[Smartisan]

What means the 26M work with older versions with autodetect but the The explicit choice of XTAL frequency has been added to menuconfig recently.We should use the older or the latest?Now we use the 26M can download flash well and the UART is well down.We can see the print when we reset the chip,but to the important it can not connect the soft AP,andcannot transive.
We want to use the 26M but it cannot work well,where the XTAL options,how can we set the xtal?
Can you post it here,which Verson IDF can find the options.ThX a lot,it is very anxious fou us

[ESP_igrr]

XTAL selection was added in 6b237de:
https://github.com/espressif/esp-idf/co ... c0ed8ec511
So if you check out the latest version of master branch, you should have this change.

But as you have correctly noted above, 26MHz should also work on earlier versions by autodetection.

We can see the print when we reset the chip,but to the important it can not connect the soft AP,andcannot transive.

Can you print out the contents of RTC_CNTL_STORE4_REG and RTC_CNTL_STORE5_REG and post them here?

[Smartisan]

Yes，we can see the print when we reset the chip,even the ssid we can see.But the chip cannot connect the soft AP, it cannot transieve
the message so it is the problenm.The early verson IDF can autodetection? Does it mean that we need not set the XTAL in the IDF？Becaus it was auto done by the software？But it was not run well ，becaus it cannot connect the soft AP! I cannot find the reason.
I will print out the contents of RTC_CNTL_STORE4_REG and RTC_CNTL_STORE5_REG and post them here tomorrow,because today we are resiting

[Smartisan]

hi，the latest version we use which we get from the github,but when we compile it was error.We do it according to your suggestion.
I attach it below.
/**********************************************************************************************************************************************************************/
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o):(.text+0x8): undefined reference to `rtc_uart_div_modify'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o):(.text+0x10): undefined reference to `rtc_uart_tx_wait_idle'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o):(.text+0x1a): undefined reference to `rtc_uart_div_modify'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `debug_print':
(.text+0x3f): undefined reference to `rtc_uart_tx_wait_idle'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_init':
(.text+0x1968): undefined reference to `rtc_init_clk'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_init_full':
(.text+0x1d02): undefined reference to `rtc_init_clk'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_init_full':
(.text+0x1d18): undefined reference to `rtc_init_clk_lite'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_init_full':
(.text+0x1d44): undefined reference to `rtc_init_clk_lite'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_usec2rtc':
(.text+0x22e0): undefined reference to `rtc_apb_freq_up'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_pad_ext_wakeup':
(.text+0x2474): undefined reference to `rtc_apb_freq_up'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_cmd_ext_wakeup':
(.text+0x2488): undefined reference to `rtc_apb_freq_up'
/mnt/hgfs/Jason/esp32/esp-idf/components/esp32/lib/librtc.a(rtc.o): In function `rtc_cmd_ext_wakeup':
(.text+0x2490): undefined reference to `rtc_uart_div_modify'
/mnt/hgfs/Jason/esp32/myapp/test3/build/esp32/libesp32.a(phy_init.o):(.literal.esp_phy_rf_deinit+0x8): undefined reference to `phy_close_rf'
/mnt/hgfs/Jason/esp32/myapp/test3/build/esp32/libesp32.a(phy_init.o): In function `esp_phy_rf_deinit':
/mnt/hgfs/Jason/esp32/esp-
/************************************************************************************************************************************************************************/
So,how can we do now? We are in time , so please help me alot.