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Topic: What about digital pin 7, handshake ? (Read 3780 times) previous topic - next topic

giodim

I'm trying to port some software running on Arduino Ethernet to my new Yun. This software uses digital pins 5,6,7 connected to two 74hc595 under an ISR routine. To access pins I use their absolute address taken from datasheet and pin mapping that varies from ATmega328 to ATmega32U4. So I remapped pin addresses in sketch for Yun but it not work !
After many tests, I feared that the problem was Yun itself, I changed all pins and magically my sketch runs !
The last trick is to use pins 4,5,6 and NOT 7. Seeing Yun schematic I note that pin7 is labelled "handshake" : what it means ?
What about the use of this pin in sketches ?

Giodim

giodim

From http://arduino.cc/en/Main/ArduinoBoardYun - External Interrupts :

"Pin 7 is connected to the AR9331 processor and it may be used as handshake signal in future. Is recommended to be careful of possible conflicts if you intend to use it as interrupt."

In other words : don't use it !
The future is now.

Giodim

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