350ms Booting Time nRF53840

RE: 350ms Booting Time nRF53840

Flaschenpost — Tue, 21 May 2024 13:21:57 GMT

Hi Vidar,

I hope to have only one button on the "clock". The whole process of booting, sending a message and shutdown shall happen in the time of the button press. The only uptime is the button press time.

I think 100 ms is ok.

But Plan B is to have light sleep or deep sleep and then use reset, but the "clock" is only used every 2 weeks for 2 hours, I have no place for an extra real power switch, and to be powered off all the other time would be the perfect scenario.

I still have to wait for the smaller modules (E73) to arrive and I still have to check your suggestion.

Thanks for all your help!

Best regards,

Marco

RE: 350ms Booting Time nRF53840

Vidar Berg — Tue, 21 May 2024 12:26:04 GMT

Hi Marco,

Bootloader implementations often focus more on features such as integrity checks of the application and DFU rather than on booting as quickly as possible. Is that something you need for your application?

Best regards,

Vidar

RE: 350ms Booting Time nRF53840

Flaschenpost — Tue, 21 May 2024 10:36:36 GMT

Thanks! I will try this CONFIG_SYSTEM_CLOCK_NO_WAIT=y.

I would like to use a faster bootloader, but I am a bit afraid to brick my module. I don't have a JLink, but I could use an STlink2 or I have read that there is a blackmagic firmware for the small and cheap "bluepill" stm32 module (which lays around and waits for a usage since years).

Which Bootloader would you suggest? I really only need to send one successful ESB message and then poweroff, no bunch of OTA Update and USB update, just any one method to update my program (double-reset + uf2 right now).

I could not find a good documentation about different bootloaders.

Best regards,

Marco

RE: 350ms Booting Time nRF53840

Vidar Berg — Tue, 21 May 2024 07:57:39 GMT

Hello,

Do you have an external J-Link debug probe you can use to program the module without using the bootloader? I don't know the exact startup time for this bootloader, but the boot time would be significantly reduced if you could remove it.

You can also try adding CONFIG_SYSTEM_CLOCK_NO_WAIT=y to your prj.conf. This will make a big difference if your are using the crystal oscillator for your 32KHz clock.

Best regards,

Vidar