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Topic: Attiny programming (Read 5086 times) previous topic - next topic

Attiny programming

Hi all,

Just to report a funny success story. I was trying to program an ATTiny13 with fairly heavy loaded pins (charliplex on all). The result:
- avrispmkII --> fail
- avr dragon --> fail
- buspirate --> success

This is done with the buspirate as prize from the 7400 logic competition :-)

Unfortunately, the buspirate does not do HV programming, so I can't actually use the reset pin (yet). This is a BP v3.6; is there a way to hack the BP so it can do HV programming? I read something that there were not enough pins on BP v3?

--
Greetings Bertho

Re: Attiny programming

Reply #1
Quote
There aren't really enough pins on the v3 Bus Pirate to do the AVR high voltage programming mode. The PIC modes work with some chips, but it is rough still.

BP v4 could do programming, but there is no production hardware (or software) to do that yet (nor is it planned, depends on the community doing it).
Ian's response from a similar thread...
best regards FIlip.

Re: Attiny programming

Reply #2
Could you not temporarily unload the pins for programming?

Re: Attiny programming

Reply #3
[quote author="Sleepwalker3"]Could you not temporarily unload the pins for programming?[/quote]

Ehm, no. It is an SOIC SMD part that is in a fixed all SMD setup. The pins are loaded by charliplex leds (and a small series resistor). The reset line is not part of the charliplex (intentionally) and there is a zener+resistor on the reset line to keep it from frying the attached LED while HV programming.

What I can do is wait with the reset-disable-fuse until I'm satisfied (hopefully). That way I can use the SPI programming with the BP.

I've adapted my program-board (with pogopins) to include a buffer on the lines. I'll try that with the dragon. HV programming is, for this first test-board, a bit awkward because I forgot to export one cpu-pin to the pogopins. A handheld wire will have to do until the board is redesigned.

Re: Attiny programming

Reply #4
Quote
There aren't really enough pins on the v3 Bus Pirate to do the AVR high voltage programming mode. The PIC modes work with some chips, but it is rough still.

This is true for AVR HVPP (High Voltage Parallel Programming) mode, but isn't really true of the much lower pin-count HVSP (Serial Programming) mode used by the 8- and 14-pin ATtiny devices, such as the ATtiny13 in question here. HVSP needs only 4 GPIO pins; 3 outputs from BP to chip (SDI, SII, SCI), 1 input from chip to BP (SDO). These map very closely to the 4 standard SPI pins. Additionally, another IO pin (likely AUX) could be used to control the +12V on to the ATtiny's RESET line.

I don't believe there exists current software to perform a burn in this manner, but building up a circuit to attach the BP and then running something custom over it in BBIO mode, perhaps using avrdude or similar, ought to be easily possible.

In fact given as I'm looking for a way to use all 12pins of a 14-pin ATtiny84, I may build myself up just such a device/program... I'll post a followup here if I do.