amiga-par-to-spi-adapter/hardware/assembly-instructions.md
Niklas Ekström f7493de0b0 Revert pin assignment of BUSY and POUT signals
The assignment of the BUSY and POUT pins to the microcontroller had
changed from the previous version to the new version. User amigos500 on
the a1k forum noted that if the assignment of those two pins had not
changed, then it would be easier to patch an old PCB to work with
the updated design.

After testing, it seems that the old pin assignment of BUSY and POUT
works equally well with the updated design, and I therefore reverted
the assignment back.
2021-07-22 21:48:59 +02:00

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# Assembly instructions
The assembly of the adapter is quite simple.
You need a parallel port connector and an Arduino Nano.
Connect the parallel port to the Nano as follows:
| Par. pin # | Par. pin | Nano pin | Atmega328P |
|---:|-----:|----:|----:|
| 2 | D0 | A0 | PC0 |
| 3 | D1 | A1 | PC1 |
| 4 | D2 | A2 | PC2 |
| 5 | D3 | A3 | PC3 |
| 6 | D4 | A4 | PC4 |
| 7 | D5 | A5 | PC5 |
| 8 | D6 | D6 | PD6 |
| 9 | D7 | D7 | PD7 |
| 10 | ACK | D9 | PB1 |
| 11 | BUSY | D4 | PD4 |
| 12 | POUT | D5 | PD5 |
| 13 | SEL | D2 | PD2 |
| 18..25 | GND | GND | GND |
## Connecting SD card module to Nano
To use the adapter with the example SD card driver (spisd.device),
connect the SD card module to the Nano as follows:
| SD card | Nano pin | Atmega328P |
|-----:|----:|----:|
| SS | D10 | PB2 |
| MOSI | D11 | PB3 |
| MISO | D12 | PB4 |
| SCK | D13 | PB5 |
| CD | D3 | PD3 |
| VCC | VCC | |
| GND | GND | GND |
CD = Card Detect. Not all modules has this pin available, but since the Micro SD card connectors typically has this pin it should be possible to solder a wire to the connector.
Note that the SD card module must have voltage level translation between the +5V used by the Amiga and the Nano, and the +3.3V used by the SD card.