Faster Boot for M0 Feather

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rafikii
 
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Faster Boot for M0 Feather

Post by rafikii »

I've noticed the M0 feather takes ~2 seconds from when power is applied to when it starts running setup(). Not sure if "boot time" or "startup time" is the right term. During this time, the built in LED is also on and it takes about 1.5mA. I am working on a project where I need it to boot much faster (sleep isn't an option), so my questions are:

1) Is there a way to reduce this boot time for the M0 feather?
2) Would the 32u4 Feather start up faster? If so, what kind of boot time should I expect?

Thanks

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mikeysklar
 
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Re: Faster Boot for M0 Feather

Post by mikeysklar »

@rafikii,

I want to say the bootloader is slowing things down and you could forgo the bootloader by using a J-Link tot upload code. However, after reading other posts on this topic it looks like some of the USB startup is substantial and people are working around it by using CRYSTALLESS.

https://forum.arduino.cc/t/arduino-zero ... /438752/14

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rafikii
 
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Re: Faster Boot for M0 Feather

Post by rafikii »

1) what file for the MO feather do i modify to add the crystalless setting?

2) would the 32u4 boot faster?

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mikeysklar
 
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Re: Faster Boot for M0 Feather

Post by mikeysklar »

The 32u4 can take up to 7s to startup with bootloader.

The easiest path is to use an M4 for instant boot.

An issue has been opened by someone else on this topic of the slow boot to intialize the external crystal.

https://github.com/adafruit/ArduinoCore-samd/issues/231

If there was a file to modify it would be this, but I don't see how to initialize the M0 here crystalless like the Arduino Zero example sighted previously.

https://github.com/adafruit/ArduinoCore ... ard_init.c

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rafikii
 
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Re: Faster Boot for M0 Feather

Post by rafikii »

dang I was hoping to use the feather with the built in radio modules

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mikeysklar
 
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Re: Faster Boot for M0 Feather

Post by mikeysklar »

One of the LoRA based M0 / 32u4 Feather boards? We do not have an M4 option today for those.

You could use a LoRA breakout or LoRA Featherwing with an M4 Feather Express.

https://www.adafruit.com/?q=lora&sort=BestMatch

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rafikii
 
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Re: Faster Boot for M0 Feather

Post by rafikii »

For the M4 do I need to change the bootloader or would it be fine as is?

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mikeysklar
 
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Re: Faster Boot for M0 Feather

Post by mikeysklar »

M4 is good as is. No modification for fast boot.

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