ATmega328P

[devilinops]

Hi im new at programing my friend lent me his usbtinyisp to program a ATmega328P but im having trouble finding what pins go where since i cant find a pin lay out for the tiny if anyone can help or show where the pins go it be appreciated.

[abqlewis]

I think your right, there isn't a specific diagram for the connectors on the USBtinyISP page (http://www.ladyada.net/make/usbtinyisp/index.html). Which is ironic since I hear a lot of people having problems hooking it up wrong (my first time for example). I think there's assumption that people are connecting to standard development board connectors.
But the USBtinyISP pages eventually link to http://www.evilmadscientist.com/article ... rgetboards which has a diagram of the ISP programming connectors. I think the diagram is for the pins on the circuit board, so the rows will be swapped as you are looking down the barrel of the cable. Of course the red stripe on the ribbon cable denotes the pin 1 end of the connector. The EMSL Page also has a link to Atmel App Note 42, which is a good, quick read if you are hooking up an AVR not on a development board.

[devilinops]

ok iv read ur links and did some more searching i fond the pin layouts bt im getting initialization failed rc=1 im trying to use the tiny to add the power but if its not enough im not sure how many volts the chip can Handel from an external power source

[abqlewis]

Unfortunately that error is pretty common, so there are lot of things it could be. If you are using an external supply to power the 328p circuit during programming, make sure to remove the EXT PWR jumper (I think it's JP3). At that point the external power is only getting to the HC125 on the TinyISP. I don't have a data sheet handy, but I'm thinking it can take anything the 328p can take. If you don't have external supply, make sure the jumper is connected. Just measure VCC at the 328p while the tinyISP is connected and on, if it's 5V your OK, if not, work your way back until you find it. Depending your development board, you might try to make sure that it can at least hold 5V on VCC, without the ISP hooked up.

[JeremyAdair]

Remember, the header is on the board the connector is at the end of the tiny. People find these header pictures and get confused because the image is mirrored.