BasicMicro - Forums

Thanks to Basic Micro's fast shipping, I now have some Nano 40s, a USB programmer board, and a dev board.
I'm want to program the Nano 40 on my system board (not the dev board). I have a three pin header on the board to connect to the USB interface board.
There must be a sequence of power up to get the bootloader's attention.
Here is the way I envision changing code on my system board:

1. Power down my system
2. Connect USB interface to my 3 pin header
3. Run Studio
4. Power up my board

At this point I believe that Studio has told the bootloader that I want to reprogram the Nano 40 and it is standing by to accept code from Studio.

Now, I finish downloading code and I want the program to run. Do I just unplug the USB interface and the bootloader lets my program run? Or, do I have to power down my system, remove the programmer and then power up again to get the new code to run?

Ideally, like the old days of the ISP Pro, I would like leave the programmer connected and have the program automatically run at the end of download. This lets me quickly change code and see results without having to disconnect anything or cycle power.

Pete

Not quite right. The nano programmers 3 pins are signal, reset and ground. So what happens is the nano programmer resets the Nano processor about 25ms before it tries to enter boot mode. If the programmer cannot reset the Nano chip it will never get into boot mode because the Nano chip only checks for attempts to enter boot mode for about 100ms after a reset.

As for running your code after programming, it should start running right away(ie about 100ms after reseting at the end of programming which is done automatically). You can leave the programmer attached or remove it at your convenience.

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Nathan Scherdin
Basic Micro - Robotic Technology Evolved