Simple, cheap, ATMega328 self programming extension board - Raspberry Pi Forums

edit schematic buggy, pin 8 , 9 of 74125 swapped, see post below

want share simple boiler-plate circuit inexpensively add arduino features rpi.
needed adc r-pi , used arduino, decided add atmega328p pi.
in addition avoid usage of external isp programmer , able directly program atmega remotely, adapted this:
http://blog.stevemarple.co.uk/2012/07/a ... using.html
respect above project i've removed transistor, because there no physical reset button here. used 74hc125 tri-state quad-buffer (because had 1 available, equivalents tri-state quad-buffers ok too) in order enable isp communication line while programming atmega (i.e. spi pins of atmega can still used during normal operations other tasks).

circuit simply:
- powering atm328 3.3v rpi
- connecting atmega serial rpi serial (no level adapters need power atm @ 3.3v)
- connecting in circuit spi via tri-state quad-buffer

schematics (possibly buggy because draw after having built actual board) edit: buggy, pin 8 , 9 of 74125 swapped, see post below

circuit.png (60.42 kib) viewed 5646 times

please note circuit design done after fact, i've implemented directly design buggy.

i've installed "ino" command line package in r-pi , modified version of avrdude includes gpio programming (see above link).

can remotely update "arduino sketches" compiling them on rpi , directly flashing them in atmega.

here couple of pictures

the simple board

20121110_075025_smaller.jpg (32.63 kib) viewed 5646 times

attched rpi

20121110_074906small.jpg (26.7 kib) viewed 5646 times

way got equivalent of arduino+ethernet shield fraction of price (and in fact quite not equivalent, way more powerful!!)

total cost:
- rpi ~35 eur
- 1 atmega 328p 4 eur
- 74hc125 < 1 eur

nice, sharing!

guess isn't possible solder headers according arduino standard due pi connector, right?

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