SparkFun Forums

[Snussbaum]

I recently submitted a support request from customer support regarding the start up delay of my Pro Mini 5 modules.
I have not heard anything back and its been a month.
I had pruchased and used 2 pro mini 5s wihtout issue on my project. Then a few weeks later I purchased 3 more pro mini 5s and these units showed a problem. As it turns out these latest pro minis I received had a start up delay from reset to start of execution of over 400ms. This delay caused the Pro Mini to miss a scan fo I2C devices and subsequently would not be detected in the system. I initially used the USB port and bootoader to download the sketch. I found that by using the ISP programming method instead, there was no significant delay. It appears the bootloader had caused this delay.
But I had asked why the 1st order of 2 modules did not have this delay even when programming over the USB port. Something changed in this process. But I cant get any answers. I prefer to use the USB port for programming as it is very siimple and straightforward but I dont know what I'm getting when I receive new units.
It would be good to have an explaination as to why this is happening. By ignoring my question it seemns you're not complying with your own rules of conduct. Can someone please tell me what is going on?

[YellowDog]

I had pruchased and used 2 pro mini 5s

What sparkfun product number are you using? Is it an actual sparkfun product or is it a clone?

It appears the bootloader had caused this delay.

Bootloaders do cause a delay at startup because that's when they are running. They are looking to see if you're uploading new code during that delay.

This delay caused the Pro Mini to miss a scan fo I2C devices and subsequently would not be detected in the system.

As long as a bootloader is on your device, there will be a delay. If you want to continue using the device with a bootloader you will need to add a delay to your I2C device scan so that it happens after your code is running on your device. You could load your sketch with a programmer and overwrite the bootloader to eliminate any delay but then you can only program via a programmer.