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Topic: Building avr programmer using FTDI Friend (Read 6158 times) previous topic - next topic

CrossRoads

Do you have the FTDI drivers installed?
http://www.ftdichip.com/FTDrivers.htm

The lack of resistor may burn out your IO pin instead of the LED.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

jbuchacher

Ugh, sorry guys. It was my IC  :(

I probably burned it when I was trying to troubleshoot what was causing my problems. The good thing is, I learned a lot and I really appreciate the help. Do you think people would find it helpful to post a tutorial on how to build a really simple programmer using an FTDI friend?

Jack Christensen


Ugh, sorry guys. It was my IC  :(

I probably burned it when I was trying to troubleshoot what was causing my problems. The good thing is, I learned a lot and I really appreciate the help. Do you think people would find it helpful to post a tutorial on how to build a really simple programmer using an FTDI friend?


We mourn the loss of your AVR. =(  But as you say, if it was an educational experience, then it may be worth it! Hope you have another.

Tutorial, maybe. Although to me, the attached should be sufficient.


CrossRoads

The schematic is not complete.  I suggest this:
Show Rx & Tx coming out of the left side of the atmega.
Add a note saying "shown with resonator/internal capaticitors; 22pF typically used with a crytal", something along those lines to explain the ground wire off the crystal.

The tutorial would address the need to change the RTS/DTR jumpers, so that would be good.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

jbuchacher

Well you guys are super helpful. I am so much more comfortable with the software side of things, and the tricky part with hardware that I discovered today was that you can't just comment lines out and attach this to that with no consequences, like you can with software. Really appreciate you guys taking the time to help a n00b

CrossRoads

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

jetjaguarxp



FTDI       ATMega    Signal direction
Vcc goes to +5/Vcc  -->
Gnd goes to Gnd        -->
CTS goes to Gnd        <--
Tx goes to Rx             -->
Rx goes to Tx            <--
On the back, cut the little jumper between the RTS pads
Add a little jumper across the DTR pads

To Use DTR, you need a 100nF (0.1uF) capacitor between the RTS pin (DTR the change above) and the ATMega's Reset pin.
DTR then goes to DTRm -->
I know this post is old but CrossRoads is absolutely correct in his recommendation.  I was able to program a breadboard arduino using his instructions.  Couldn't find anything quite this clear even after almost 4 years.

Thanks!

chipaudette

Yes, this thread is very helpful.  The need to add the cap in-series with the RTS line is key.

Chip

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