/* * File: main.c * Author: boos * * Created on 17. September 2021, 03:49 */ // CONFIG1 #pragma config FOSC = INTOSC // Oscillator Selection Bits (INTOSC oscillator: I/O function on CLKIN pin) #pragma config WDTE = OFF // Watchdog Timer Enable (WDT disabled) #pragma config PWRTE = OFF // Power-up Timer Enable (PWRT disabled) #pragma config MCLRE = OFF // MCLR Pin Function Select (MCLR/VPP pin function is digital input) #pragma config CP = OFF // Flash Program Memory Code Protection (Program memory code protection is disabled) #pragma config BOREN = OFF // Brown-out Reset Enable (Brown-out Reset disabled) #pragma config CLKOUTEN = OFF // Clock Out Enable (CLKOUT function is disabled. I/O or oscillator function on the CLKOUT pin) #pragma config IESO = OFF // Internal/External Switchover Mode (Internal/External Switchover Mode is disabled) #pragma config FCMEN = OFF // Fail-Safe Clock Monitor Enable (Fail-Safe Clock Monitor is disabled) // CONFIG2 #pragma config WRT = OFF // Flash Memory Self-Write Protection (Write protection off) #pragma config CPUDIV = CLKDIV6 // CPU System Clock Selection Bit (CPU system clock divided by 6) #pragma config USBLSCLK = 48MHz // USB Low SPeed Clock Selection bit (System clock expects 48 MHz, FS/LS USB CLKENs divide-by is set to 8.) #pragma config PLLMULT = 3x // PLL Multipler Selection Bit (3x Output Frequency Selected) #pragma config PLLEN = ENABLED // PLL Enable Bit (3x or 4x PLL Enabled) #pragma config STVREN = ON // Stack Overflow/Underflow Reset Enable (Stack Overflow or Underflow will cause a Reset) #pragma config BORV = LO // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (Vbor), low trip point selected.) #pragma config LPBOR = OFF // Low-Power Brown Out Reset (Low-Power BOR is disabled) #pragma config LVP = OFF // Low-Voltage Programming Enable (High-voltage on MCLR/VPP must be used for programming) #include // define MAX7219 register addresses (for convenience) #define MAX7219_MODE_NOP 0b00000000 #define MAX7219_MODE_DECODE 0b00001001 #define MAX7219_MODE_INTENSITY 0b00001010 #define MAX7219_MODE_SCANLIMIT 0b00001011 #define MAX7219_MODE_SHUTDOWN 0b00001100 #define MAX7219_MODE_TEST 0b00001111 // define MAX7219 commands (for convenience) #define MAX7219_NO_DECODE 0b00000000 #define MAX7219_7SEG_DECODE 0b11111111 // define functions void MAX7219_send (unsigned char a, unsigned char d); void MAX7219_update (void); //default brightness unsigned char brt = 15; // abbreviations for convenience #define SW1 RA5 #define LED RC2 #define DATA RC5 #define LOAD RC4 #define CLK RC3 // main function void main (void) { // set up port RA5 for the pushbutton // it is an input TRISA5 = 1; // enable weak pull-up resistors WPUA5 = 1; nWPUEN = 0; // set up ports RC2, RC3, RC4, and RC5 to control the MAX7219 // they are all outputs TRISC5 = 0; TRISC4 = 0; TRISC3 = 0; TRISC2 = 0; // disable analog features on ports RC2 and RC3 ANSC2 = 0; ANSC3 = 0; // set up the four MAX7219's of the 8x32 dot matrix module // scan all eight rows MAX7219_send(MAX7219_MODE_SCANLIMIT, 7); MAX7219_send(MAX7219_MODE_SCANLIMIT, 7); MAX7219_send(MAX7219_MODE_SCANLIMIT, 7); MAX7219_send(MAX7219_MODE_SCANLIMIT, 7); MAX7219_update(); // set MAX7219 to no-decoding mode // (we are specifying the pattern manually) MAX7219_send(MAX7219_MODE_DECODE, MAX7219_NO_DECODE); MAX7219_send(MAX7219_MODE_DECODE, MAX7219_NO_DECODE); MAX7219_send(MAX7219_MODE_DECODE, MAX7219_NO_DECODE); MAX7219_send(MAX7219_MODE_DECODE, MAX7219_NO_DECODE); MAX7219_update(); // set MAX7219 brightness to maximum // (any number from 0-15 works) MAX7219_send(MAX7219_MODE_INTENSITY, 15); MAX7219_send(MAX7219_MODE_INTENSITY, 15); MAX7219_send(MAX7219_MODE_INTENSITY, 15); MAX7219_send(MAX7219_MODE_INTENSITY, 15); MAX7219_update(); // turn ON MAX7219_send(MAX7219_MODE_SHUTDOWN, 1); MAX7219_send(MAX7219_MODE_SHUTDOWN, 1); MAX7219_send(MAX7219_MODE_SHUTDOWN, 1); MAX7219_send(MAX7219_MODE_SHUTDOWN, 1); MAX7219_update(); // clear all dot matrix displays MAX7219_send(1, 0); MAX7219_send(1, 0); MAX7219_send(1, 0); MAX7219_send(1, 0); MAX7219_update(); MAX7219_send(2, 0); MAX7219_send(2, 0); MAX7219_send(2, 0); MAX7219_send(2, 0); MAX7219_update(); MAX7219_send(3, 0); MAX7219_send(3, 0); MAX7219_send(3, 0); MAX7219_send(3, 0); MAX7219_update(); MAX7219_send(4, 0); MAX7219_send(4, 0); MAX7219_send(4, 0); MAX7219_send(4, 0); MAX7219_update(); MAX7219_send(5, 0); MAX7219_send(5, 0); MAX7219_send(5, 0); MAX7219_send(5, 0); MAX7219_update(); MAX7219_send(6, 0); MAX7219_send(6, 0); MAX7219_send(6, 0); MAX7219_send(6, 0); MAX7219_update(); MAX7219_send(7, 0); MAX7219_send(7, 0); MAX7219_send(7, 0); MAX7219_send(7, 0); MAX7219_update(); MAX7219_send(8, 0); MAX7219_send(8, 0); MAX7219_send(8, 0); MAX7219_send(8, 0); MAX7219_update(); // main loop while (1) { // increase brightness if the button is pressed if (!SW1) { LED = 1; brt += 1; if (brt > 15) { brt = 0; } } else { LED = 0; } // update the brightness MAX7219_send(MAX7219_MODE_INTENSITY, brt); MAX7219_send(MAX7219_MODE_INTENSITY, brt); MAX7219_send(MAX7219_MODE_INTENSITY, brt); MAX7219_send(MAX7219_MODE_INTENSITY, brt); MAX7219_update(); // send out sample data MAX7219_send(8, 0b00001111); MAX7219_send(8, 0b00000111); MAX7219_send(8, 0b00000011); MAX7219_send(8, 0b11111111); MAX7219_update(); MAX7219_send(7, 0b00001111); MAX7219_send(7, 0b00000111); MAX7219_send(7, 0b00000011); MAX7219_send(7, 0b01111111); MAX7219_update(); MAX7219_send(6, 0b00001111); MAX7219_send(6, 0b00000111); MAX7219_send(6, 0b00000011); MAX7219_send(6, 0b00111111); MAX7219_update(); MAX7219_send(5, 0b00001111); MAX7219_send(5, 0b00000111); MAX7219_send(5, 0b00000011); MAX7219_send(5, 0b00011111); MAX7219_update(); MAX7219_send(4, 0b00001111); MAX7219_send(4, 0b00000111); MAX7219_send(4, 0b00000011); MAX7219_send(4, 0b00001111); MAX7219_update(); MAX7219_send(3, 0b00001111); MAX7219_send(3, 0b00000111); MAX7219_send(3, 0b00000011); MAX7219_send(3, 0b00000111); MAX7219_update(); MAX7219_send(2, 0b00001111); MAX7219_send(2, 0b00000111); MAX7219_send(2, 0b00000011); MAX7219_send(2, 0b00000011); MAX7219_update(); MAX7219_send(1, 0b00001111); MAX7219_send(1, 0b00000111); MAX7219_send(1, 0b00000011); MAX7219_send(1, 0b00000001); MAX7219_update(); } return; } // This function sends out the address byte "a" and the data byte "d" in the MAX7219 format // (Sequence of bits is a7-a6-a5-a4-a3-a2-a1-a0-d7-d6-d5-d4-d3-d2-d1-d0.) void MAX7219_send (unsigned char a, unsigned char d) { // send out address byte, start with most significant bit and work backwards for (int i=7; i>=0; i--) { DATA = (a >> i) & 1; CLK = 1; CLK = 0; } // send out data byte, start with most significant bit and work backwards for (int i=7; i>=0; i--) { DATA = (d >> i) & 1; CLK = 1; CLK = 0; } // reset the data pin back to zero // (so that it is not left ON if the last sent bit was a 1) DATA = 0; } // This function pulls the LOAD pin high and then back to zero, so that the transmitted data // appears in the MAX7219's output stage. void MAX7219_update (void) { LOAD = 1; LOAD = 0; }