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Step 3The Programming Cradle
In Ghetto Programmer v.1.0 I used a programming cradle with a non-standard pin input and with female pin-headers to stick stuff into.
Non-standard pins are a bad idea because you'll not be able to use your cradle with someone else's programmer, and vice-versa.
Female pin-headers were fun because you could directly plug LEDs into them, but when I'd start doing something more complex, I'd end up wiring it into a breadboard anyway. With the new cradle, I cut out the middleman. Less hand-wiring = better.
But the biggest advantage of this cradle design is that you can plug in the cradle almost anywhere you could plug in the AVR chip. This turns out to be huge. Instead of designing ISP circuits into your robot or whatever, you just stick this cradle thing into the IC socket. Then you can program/re-program your robot's brain in circuit. When you're done developing, plug the AVR in directly and you're on to the next one.
Making the cradles is easy enough -- all you need to do is connect the pins from the 6-pin header to the right places on the chips. This time 'round, I used etched PCBs. You can just as well hand-wire the whole thing on perfboard.
The ATTiny13/15 cradle is made with an 8-pin wire-wrap socket. I love these. It's easy to insert the chip into its nice round holes and the long legs provide extra clearance on the breadboard. I made the PCB traces by freehand with a Sharpie.
The ATTiny2313 cradle was made with Eagle and the laser paper toner transfer method. I couldn't find any 20-pin wire-wrap sockets, so I had to resort to a 20-pin regular socket soldered onto 2 10-pin pin headers. This ends up with a cradle with shorter legs, but it works. The schematic and the PDF I used for the circuit are below.
On both, I had to hand-wire an extra line. Such is life.
Non-standard pins are a bad idea because you'll not be able to use your cradle with someone else's programmer, and vice-versa.
Female pin-headers were fun because you could directly plug LEDs into them, but when I'd start doing something more complex, I'd end up wiring it into a breadboard anyway. With the new cradle, I cut out the middleman. Less hand-wiring = better.
But the biggest advantage of this cradle design is that you can plug in the cradle almost anywhere you could plug in the AVR chip. This turns out to be huge. Instead of designing ISP circuits into your robot or whatever, you just stick this cradle thing into the IC socket. Then you can program/re-program your robot's brain in circuit. When you're done developing, plug the AVR in directly and you're on to the next one.
Making the cradles is easy enough -- all you need to do is connect the pins from the 6-pin header to the right places on the chips. This time 'round, I used etched PCBs. You can just as well hand-wire the whole thing on perfboard.
The ATTiny13/15 cradle is made with an 8-pin wire-wrap socket. I love these. It's easy to insert the chip into its nice round holes and the long legs provide extra clearance on the breadboard. I made the PCB traces by freehand with a Sharpie.
The ATTiny2313 cradle was made with Eagle and the laser paper toner transfer method. I couldn't find any 20-pin wire-wrap sockets, so I had to resort to a 20-pin regular socket soldered onto 2 10-pin pin headers. This ends up with a cradle with shorter legs, but it works. The schematic and the PDF I used for the circuit are below.
On both, I had to hand-wire an extra line. Such is life.
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Apr 11, 2009. 4:14 AMBlackHatCracker
says:
Ok a simple solution to fixing both of those is to make the board a little wider... No problem there.
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