An SD SPI driver for the PIC18F46K22 microcontroller. This driver can be used to read and write to individual blocks on the card without an underlying filesystem.
A PIC18F microcontroller, SD card socket and and SD card are required. Pullups may also be required for the SPI data lines depending on your setup.
The table below shows the default pin assignments.
| SD Card pin | SPI pin | PIC gpio pin | DDR config |
|---|---|---|---|
| D0 | MISO | Pin 20 (RD1) | Digital Input |
| D3 | CS | Pin 22 (RD3) | Digital Output |
| CLK | SCK | Pin 20 (RD0) | Digital Output |
| CMD | MOSI | Pin 27 (RD4) | Digital Output |
| USART cable | line Color | PIC gpio pin |
|---|---|---|
| TX | Green | Pin 30 (RD7 optional) |
| RX | White | Pin 29 (RD6) |
| GND | Black | GND |
| POWER | Red | NC (Not needed) |
The SSP module 1 is configured to print log output over uart at 115k baud. SPI communication is handled throgh the 2nd module (SSPM2).