raymadigan
Member
I have run out of pins, and want to use pins 23 and 24. I read in one of the forum entries that code like
void setup(){
SerialUSB.end();
usbPowerOff();
}
will allow the pins to be made available with pinMode ...
does this make it so once the sketch is uploaded then no other programs can be uploaded because this is the running program? Or does this still allow the bootloader to operate?
raymadigan
Member
It's worse then that. Before I figured this out I started pulling pin 23 high to turn on an led. When it didn't work I read that it was also one of the usb pins. Now the serial port is not available and it seems that I cannot write another sketch to the maple mini.
Is there anyway around this?
raymadigan
Member
the problem is now I can't talk to the maple.
Nothing is wrong with my approach, I just didn't figure out in the beginning that the pins labeled USB are also the pins that are connected to the usb socket and if used make it so the ide can't talk to the device. Silly mistake, but now I either have to buy a new device or something. I used the pins because they seemed available.
I like the maple mini because I can solder it to my pc board and all of the hardware is in one board.
raymadigan
Member
Thank you for the help.
I read the Tips and Tricks, Perpetual Bootloader Mode to make sure I was doing it correctly. I think I did it, the board stays in the slow blink mode and doesn't seem to run the program. However my PC can't see the com port to upload a program to it.
raymadigan
Member
I just figured out the problem, I left the led's connected to the usb pins. Once I removed them I was able to put it in perpetual bootloader mode and write the bare minimum sketch to the device and it works again.
I do want to use these pins, so would an idea like this work:
put a 2 position dip switch between the maple and the wires that connect to the led's. When open I can load a program from the perpetual bootloader.
If I know to stop writing to the pins. My loop checks several other dip switches and one of those could be used to signal to stop writing to the pins and enable the usb function.
mikep
Member
As feurig mentioned, you could use some shift registers (http://www.arduino.cc/en/Tutorial/ShiftOut) to give you more output pins. The 74HC595 is pretty inexpensive and gives you an additional 8 output pins by using 3 of the Arduino/Maple pins.
You must log in to post.
