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Programme de démo pour la gestion de 4 afficheurs 64 leds
Diff: main.cpp
- Revision:
- 0:bd34a367f642
- Child:
- 1:61f61158c345
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Tue Nov 24 06:41:43 2015 +0000 @@ -0,0 +1,70 @@ +/* 06_spi_max7219_led8x8 + * + * Simple demo to drive a 8x8-as LED matrix by a MAX7219 LED driver IC + * After initialisation two characters (H and W) are displayed alternatively. + * The MAX7219 IC is driven by hardware SPI: SPI0 module at PTD1, PTD2, PTD3. + */ + +#include "mbed.h" + +SPI spi(PTD2, PTD3, PTD1); // Arduino compatible MOSI, MISO, SCLK +DigitalOut cs(PTD0); // Chip select + +const unsigned char led1[]= { + 0xFF,0x18,0x18,0x18,0x18,0x18,0x18,0xFF +}; //H +const unsigned char led2[]= { + 0x1F,0x60,0x80,0x40,0x40,0x80,0x60,0x1F +}; //W + +/// Send two bytes to SPI bus +void SPI_Write2(unsigned char MSB, unsigned char LSB) +{ + cs = 0; // Set CS Low + spi.write(MSB); // Send two bytes + spi.write(LSB); + cs = 1; // Set CS High +} + +/// MAX7219 initialisation +void Init_MAX7219(void) +{ + SPI_Write2(0x09, 0x00); // Decoding off + SPI_Write2(0x0A, 0x08); // Brightness to intermediate + SPI_Write2(0x0B, 0x07); // Scan limit = 7 + SPI_Write2(0x0C, 0x01); // Normal operation mode + SPI_Write2(0x0F, 0x0F); // Enable display test + wait_ms(500); // 500 ms delay + SPI_Write2(0x01, 0x00); // Clear row 0. + SPI_Write2(0x02, 0x00); // Clear row 1. + SPI_Write2(0x03, 0x00); // Clear row 2. + SPI_Write2(0x04, 0x00); // Clear row 3. + SPI_Write2(0x05, 0x00); // Clear row 4. + SPI_Write2(0x06, 0x00); // Clear row 5. + SPI_Write2(0x07, 0x00); // Clear row 6. + SPI_Write2(0x08, 0x00); // Clear row 7. + SPI_Write2(0x0F, 0x00); // Disable display test + wait_ms(500); // 500 ms delay +} + +int main() +{ + cs = 1; // CS initially High + spi.format(8,0); // 8-bit format, mode 0,0 + spi.frequency(1000000); // SCLK = 1 MHz + Init_MAX7219(); // Initialize the LED controller + while (1) { + for(int i=1; i<9; i++) // Write first character (8 rows) + SPI_Write2(i,led1[i-1]); + wait(1); // 1 sec delay + for(int i=1; i<9; i++) // Write second character + SPI_Write2(i,led2[i-1]); + wait(1); // 1 sec delay + } +} + + + + + +