Well this is not spi programming it is high voltage serial programming that you still can use if for instance spi icsp is disabled.
High voltage serial programming unbrick.
Here are some ways to generate that 12v signal depending on what components you have at hand.
One of the pins is sci serial clock input one is sdi data in to the chip one is sii instruction in to the chip and one is sdo.
Uc to be unbricked.
As their name implies the high voltage serial and high voltage parallel programming techniques require a 12v signal.
If you really want to use high voltage serial programming to download a sketch then the instructions to implement a full blown programmer are documented in section 20 6 in the attiny85 datasheet.
With this mechanism it is possible to bring the mcu back to life.
Its correctly changing between 12v and 0v as per the program.
The code in this project uses arduino nano to re program attiny85 microcontroller fuses to default values using the hvsp method.
It should be noted that the current drawn from this signal is quite small.
If you need to make changes later on then high voltage programming is used to reset the fuses so the regular programmer can download the sketch again.
Attiny44a pa0 pa1 and pa2 are grounded.
So bc548 is working as expected.
High voltage programming of atmega328p and other atmel chips on a breadboard.
This procedure shows how to set up an arduino as a high voltage programmer using a very small number of components.
12v bench power supply.
On the chips with a small number of pins high voltage serial programming can be used for this purpose and on ones with more pins high voltage parallel programming does a similar thing.
Arduino nano board loaded with avr high voltage serial fuse reprogrammer given above.
Hvsp requires 7 signals including power and ground as shown in this illustration.
Connecting your standard arduino.
For high voltage programming the timing of the power pin matters so it is software controlled through the svcc pin rather than.
Atmel attiny datasheet chapter high voltage serial programming describes alternative way of programming attiny microcontroller.
I am trying to re fuse my bricked 328p by constructing a high voltage programmer from this and similar posts.
I verified voltage on reset pin pb3 pin4 using dmm.
Transistor small inexpensive 12v battery a paper clip three resistors led and assorted wire and breadboard.
I think we are cross purposes a bit because an earlier post on page 1 of this thread talked about using high voltage programming to unbrick the chip.
