Connection ISP Pins 8 and 10

General discussions about V-USB, our firmware-only implementation of a low speed USB device on Atmel's AVR microcontrollers
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Faralla

Connection ISP Pins 8 and 10

Post by Faralla » Sat Feb 03, 2007 6:25 pm

Hi,

when looking at the ISP parts for example in the circuit for PowerSwitch I see that Pin 8 and 10 of the ISP connector are connected to PD0 and PD1 and thus to ground.
What is the meaning of doing this?

christian
Objective Development
Objective Development
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Joined: Thu Nov 09, 2006 11:46 am

Post by christian » Sat Feb 03, 2007 9:19 pm

Since it's not necessary to have four ground pins, I usually connect two of them to RxD and TxD for debugging purposes. AVR-Doper can even read the debug info from these pins.

If you use AVR-Doper for In System Programming, you can print debug info through the ISP cable and AVR-Doper.

The additional resistor limits the current if a programmer with four ground pins is connected.

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