I can not get any device to successfully communicate with the micro for programing. Ive tried a jtagice mkII and a avrisp mkII with no sucess. Ive checked and rechecked connections and everything seems to be fine. The only thing im not sure about is SCK goes to USCK right? Im out of ideas :-/
its ither something really stupid im overlooking or something rather large i dontk now about with these devices. Ive only worked with megas up to this point. any one have any ideas?
You didn’t mention which chip you have, but looking at the ATtiny24 which I’m currently working with, SCK is connected to the USCK pin and it works fine that way.
I don’t know if it matters, but I’m using a 6pin programming connection on my project instead of the 10pin header configuration. Otherwise programming the ATtiny is the same as programming the ATmega. If you can program ATmega parts, the problem has to be in the wiring somewhere.
Do you have anything connected in the circuit to the programming pins? You could try disconnecting the other components and trying again - just in case they are interfering with the programming process.
its an ATtiny44. Im using the 6 pin configuration that I always use for my projects as well. I did have something else connected to the circuit but ive sence disconnected it as I started to trouble shoot the thing.
i did find [this post on avr freaks where someone talks about dW not working, but dosent say anything about ISP.
Im going to check and recheck everything today. Hopefully just a good nights sleep was what i needed to figure this out.](http://www.avrfreaks.net/index.php?name=PNphpBB2&file=printview&t=63014&start=0)
I ended up sawping the chip and it worked fine
I wasted 2 hours on that lol.
I found figured out something that i thought was strange thow; Im using the tiny44 to control a Allegro [A6281 LED driver IC. Which operates on the SPI buss meaning its on the same pins used for ISP. Thinking it would interfear like you said i put a jumper on the board which i could pull to disconnect the power going to the A6281 while programing the µC, and avoid any problems. The strange thing is when i pull the jumper I am unable to program the µC. But when i put the jumper on, and the A6281 powered up during ISP it works fine. I just thought that was strange, i guess maybe the LED driver IC is putting extra capacitance on the line when its not powered or something like that.
Also using SPI on a tiny is like going back to the stone age when compared to a mega.](http://www.allegromicro.com/en/Products/Part_Numbers/6281/)
Glad you got it working. I was reading the manual for one of my programmers this morning (which I admit, I don’t tend to read the instructions that come with these things). In the manual they list some electrical requirements for other components attached to the programming pins. For instance, the /reset line shouldn’t be pulled up with a resistor value less than 10k ohms. So, I guess it’s certainly possible for other components to interfere, depending on the situation.
I know the SparkFun serial LCD module doesn’t like being on the same lines as the ISP header. Programming the MCU tends to do wierd things like change the baud rate or turn off the backlight.