AVR ISP Galvanic Isolation

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I had done a project where the AVR is powered via the main 110Vac line,  So I had to find a solution to be able to test my code in real life, I had look to many thing and found very cool opto-isolator, "you must check the datasheet IL717"


  • 2500v isolation
  • 3 state the ISP port on your AVR when not in programming session
  • Very low cost
  • Easy to build
  • Work with 3.3v or 5v AVR

    The circuit is simple, all your signal line (MISO,MOSI,SCK,RESET) must pass trough the isolator, and you need a simple TTL tranceiver to 3 state AVR port when you are not in programming mode.  You need a very small modification in your AVRUSB programmer,  You need to send 5V to OptoBoard check the picture





3 Comments to “AVR ISP Galvanic Isolation”

  • hadi fathi June 10, 2011 at 11:02 am

    tank you.

  • John J. Smith February 26, 2012 at 10:02 am

    >> found very cool opto-isolator

    IL717’s not an opto – there are no optos for such speeds. It’s GMR (http://en.wikipedia.org/wiki/Giant_magnetoresistance).

    There are Silabs’ SI8xxx, Analog Devices’ ADUM24xx and Texas Instruments’ ISO72xx chips also available for such purposes.

  • MaryLi August 22, 2012 at 6:03 am

    We design and produce RS232/RS485/TTL UART to Ethernet/WIFI/GPRS convert product. We can supply OEM and ODM service.
    glad to see my website :http://www.tcp232.net

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Please note

All my source codes were taken from my personal projects.

Everything is for your information only. The C/C++ codes have been written
with ICCAVR. You can find the header and source CRT files by downloading their compiler.

All is for your information and everything is AS IS without any warranty of any kind. No other files are available and I don't make any modification for any body.



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