Arduino Pro Micro 8 second startup delay

Hello friends,

A while ago I became interested in smaller projects and I decided to buy a few Sparkfun Pro Micro's. The first batch I received had a USB mini connector and worked great.

https://www.sparkfun.com/products/12640

The second batch I received we're a new revision and had a USB micro connector, no biggie. The thing that struck me though was that my sketch wouldn't boot immediately (only after 8 seconds). I found some reference to it and I didn't like it ..

Now the third batch has come in and these seem to have a new bootloader yet again. The Sparkfun website also has a document called "firmware note" that talks a little out it. Basically my sketches on these boards are loaded immediately again.

My question: I have a few of these boards laying around the house that have the 8 second delay feature. Is there any way for me to prep these boards with the newest bootloader? Now that the new batch doesn't have this feature I am really bothered by it.

I have a USB Serial Light adapter, a Tiny Programmer and a Arduino Duemilanove and the Pro Micro's have USB to them as well.

Hope you can help thanks

Is there any way for me to prep these boards with the newest bootloader?

Yes

http://www.arduino.cc/en/Tutorial/ArduinoToBreadboard

Thanks for that link.

I'd like to try and burn a new bootloader onto the 32u4. Do I really need to program it through my Duemilanove board? Can't I just burn a bootloader via the USB on the 32u4? Why not?

Where can I find these bootloaders and more information about them? A side from the firmware note I have mentioned I am only guessing that the bootloader itself contains this delay.

Can anyone confirm that I am on the right track here?

Can't I just burn a bootloader via the USB on the 32u4?

No.

Why not?

Because the botloader talks to the USB and if you are reprogramming it then you are trying to replace code that you are running. The rug is pulled from under you.

Where can I find these bootloaders

They are in the files that make up the Arduino IDE.

more information about them?

Normally on something like the Git hub account they are hosted on, see the code of the boot loader for information.

A side from the firmware note I have mentioned I am only guessing that the bootloader itself contains this delay.

Any delay is not deliberate, that would be just silly. Part of the delay comes from trying to enumerate the processor as a USB device and could be down to your PC.

This page seems to summarize it nicely:

http://joshfire-tech.tumblr.com/post/82896375379/upgrading-the-bootloader-on-arduino-micro-with

Normally on something like the Git hub account they are hosted on, see the code of the boot loader for information.

I've been looking here but those files haven't been updated in years.

https://github.com/arduino/Arduino/tree/master/hardware/arduino/avr/bootloaders/caterina

I'm not conviced that I'll find the new version of this bootloader here. I am also very interested to study the source code regarding the problem that was solved.

What should I do? Should I assume that the latest Arduino IDE build has the correct files and try to perform a burn with it?

ps; the forementioned blog post has some details on how to use any arduino board with the Arduino ISP sketch to burn the bootloader if I am not mistaking.

Should I assume that the latest Arduino IDE build has the correct files and try to perform a burn with it?

Yes, it has all the source code already in it.

Right! It works like a charm.

I followed this guide to the letter: https://coytar.wordpress.com/2013/04/27/use-arduino-uno-as-an-avr-isp-to-burn-the-bootloader-to-a-sparkfun-pro-micro-5v/

Very happy! Whooray