From a807f4849155262efb243c574dd5d77f35755ebc Mon Sep 17 00:00:00 2001 From: Sadeep Madurange Date: Sat, 8 Mar 2025 15:26:31 +0800 Subject: wip: spi interface. --- main.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'main.c') diff --git a/main.c b/main.c index f63f5ee..082d9d5 100644 --- a/main.c +++ b/main.c @@ -1,10 +1,52 @@ +#include +#include #include #include "uart.h" +#define SPI_SS PB2 +#define SPI_SCK PB5 +#define SPI_MISO PB4 +#define SPI_MOSI PB3 +#define SPI_DDR DDRB +#define SPI_PORT PORTB + +static inline uint8_t read_reg(uint8_t reg) +{ + SPI_PORT &= ~(1 << SPI_SS); + + SPDR = reg & 0x1F; + while (!(SPSR & (1 << SPIF))) + ; + + SPDR = 0xFF; + while (!(SPSR & (1 << SPIF))) + ; + + SPI_PORT |= (1 << SPI_SS); + return SPDR; +} + +void radio_init(void) +{ + SPI_DDR |= (1 << SPI_SS) | (1 << SPI_SCK) | (1 << SPI_MOSI); + SPI_PORT |= (1 << SPI_SS); + SPCR |= (1 << SPE) | (1 << MSTR); +} + int main(void) { uart_init(); + radio_init(); + + for (int i = 0; i < 10; i++) { + uint8_t val = read_reg(0x00); + + uart_write("CONFIG: "); + uart_write_char(val); + uart_write_char('\r'); + uart_write_char('\n'); + } return 0; } -- cgit v1.2.3