![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhl_qA79zNhqKO4WxjE-AnsFs6uZKwGu3l-I0_3BcGDcjoyBltLa3LKZaRtRuYW1NwB9SPBaSIwTM1c0z5m3ew4MA1Inj1v8FYT8vw9kTYI4LTclP_73afbcymHQAcSO-MBX5rWEjoWDYk/s400/usbasp_complete.jpg)
Just made an USBasp. It's a USB AVR in-system programmer project by Thomas Fischl. Used the PCB by J.A. de Groot found on the USBasp project page. Had to add 2 missing zeners, but other than that the build was straightforward and problem-free.
This programmer handles USB communication in firmware on an AtMega8 or 48.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjv1MVBtpxMKn7ze5qjTBRgQp8gSJFkGtSRJDuxvGJ7JULfc95ETqg5Mme2sXQV4aLRqacUAqFI8eO1k_ACrefqGbZLpZWvs-0Y_GWRbrUVpzsLiAN8OJmBsnTvBlL_v3rvagcyW6zAODE/s400/usbasp_zener.jpg)
Tested with ATTiny2313 and ATMega8 sofar. Works fine.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-myrV8mWcvlt792Q6vObnZwUk91G2XC45y0M8V7Gy1ZWVu2-yUXvJxEG3-6cG_-UVZ072vh77O1wxyO6ORHxoOnFMGr9uVUd-3I0boKd9Y17o25_dCz2XutE9dp8rhtKGcBPx5QR-9Pw/s400/usbasp_working.jpg)
No need to bother with the LPT port anymore.
Hi Viktor,
ReplyDeleteI am also making the same usbasp using J.A. de Groot, but it doesn't work.
I have just realized that the board misses the 2 zener diodes as you said.
Does your work without these 2 zeners, or you have to add them to make it to work?
Thanks.
Dave
It worked briefly on a certain USB hub but not when connected directly to a pc.
DeleteWorks fine everywhere with the diodes added.
I have the same hardware and my is working well without the zenners.
ReplyDeleteNo mater is the hardware direct connected to the PC usb or through a hub.
You got lucky with your motherboard being more tolerant to out-of-spec voltages. See: http://vusb.wikidot.com/hardware
DeleteFor others it won't work: http://www.avrfreaks.net/forum/cannot-detect-usb-asp-programmer-windows-81