Hello guys, I need help programming attiny85 using the arduino mega 2560, I'm trying to do it for almost 2 days. But I'm not sure if it's possible to program attiny85 using mega 2560. :-\ Can anyone enlighten me?
Thanks
Hi
What problems are you finding? You've not given us much info to work on here.
Are you using a version of ArduinoISP that has the pins modified to the IO pin locations required on the mega? ArduinoISP as standard is setup for the Uno style board. Comments in this version spell out the required changes.
Let everyone know what error or issue you're specifically seeing, and how far you get before you see it.
Cheers!
Geoff
I was trying to get my mega as ISP for ATTiny85, by studying this link: High-Low Tech – Programming an ATtiny w/ Arduino 1.6 (or 1.0) and this one: http://blog.the-jedi.co.uk/2013/06/03/attiny85-programming-using-mega2560-as-isp/
But somehow, I got this kind of error: avrdude: stk500_getsync(): not in sync: resp=0x00
I researched and saw this topic in the arduino forum: Mega 2560 as ISP for ATTiny - Microcontrollers - Arduino Forum
But still, I can't make it work.
I was trying to create an rfid reader by programming 2 attiny85 using arduino mega and RC522 as the reader, also I needed 2 attiny because I was thinking using the other one for VUSB and the other for reading the rfid.
Do you think this project is possible?
Thanks in advance.
Hi,
It might be worth posting a photo of your setup to see if there's anything you're staring at but not seeing.
As for the practicality - I often find myself working out how to squeeze a project into one or more ATtiny85s but I'm mindful that to the man with a hammer, every problem is a nail and the cost difference of two ATtiny compared to a single ATmega328 is minimal...though it's about the challenge as much the outcome too 
Cheers!
Geoff
This is my current setup, the capacitor is 10uF as said in the first link I posted, I tried using a 2200uF since that's what I got right now, planning to buy a 47uF later.
If Nick suggests 47uF I'd respect his advice and switch. 10uF is fine for Uno but I've never had the need to break out a mega to program so can't confirm if that's your deal-breaker, though I suspect it is.
Your photo is indistinct so it makes it appear that the reset (blue) is going to the left side of the double header, which isn't where 53 is, but there are 2 blue wires and it does get cluttered and confused there.
I'd start with the cap. If you don't have a 47uF you could likely substitute 5x 10uF in parallel (=50uF) if you've got those.
All the best,
Geoff