Anyway to speed up the boot up time

[wanqiu]

Currently, it takes about 300ms for the system to start executing the user_init() code. I guess there are many modules to be initialised.
Is there any possibility that we can configure which modules to be initialised during boot up so that we can speed up the boot up time.
For example, we might not need to initialise the RF module during boot up?

[Helios]

The RF initialization takes most of the 300mS.
When ESP8266 wake up from deep-sleep, the SDK provide the options to disable RF initilization.

Could you kindly try the deep-sleep options? Check whether the booting time is good enough for your applications.
system_deep_sleep_set_option(4); // don't enable RF module
or
system_deep_sleep_set_option(2); // don't enable RF calibration

[Helios]

If this API is helpful, Espressif Engineers shall add it into normal booting besides deep-sleep wakeup. Thank.

[tve]

How often is the RF module recalibrated if the module stays powered-on permanently?

[Helios]

the RF calibrations are background tasks and transparent for user's software.

[tve]

I understand that the calibration happens in the background. I'm wondering about the need to calibrate at boot. How do you recommend I decide whether calibration is needed at boot? If you tell me that normally recalibration happens every 60 seconds and my module goes into deep sleep for 1 second then I don't need to recalibrate at boot. But if my module goes into deep sleep for 10 minutes then I should really do the recalibration at boot. Can you please provide some information about how often the recalibration happens when the module is not sleeping?

[wanqiu]

Thanks for replies.
For our case, it is crucial that we can turn off the RF calibration part during startup.
Basically, we have a sensor attached to this system. When power on, we check the sensor status, and only when the status changed, it reports to server, otherwise, it will be turned off by external power gate. By doing so, we achieved the best power usage scenario.
Please do help us with a new API for this.

[Helios]

Hi tve,
The RF calibration after booting need not stop software and will not affect the sleep processes.
No problem to do deep-sleep per 1S.

[Helios]

Hi Wanqiu
Thanks for your information.
As you know, we have provided such API for deep-sleep.
However, you apply the external circuit to do power gating, rather than deep-sleep.

We will provide the API for your case as soon as we finish the testing.

[rith87]

@Helios: So what is the API to disable RF during bootup?