MAX7219/MAX7221 dirver + example

2017-02-09 03:31:51 +05:00 · 2017-02-09 03:31:51 +05:00 · 87b4befd87
commit 87b4befd87
parent c21f70366f
6 changed files with 383 additions and 0 deletions
--- a/extras/max7219/max7219.c
+++ b/extras/max7219/max7219.c
@ -0,0 +1,189 @@
+/*
+ * Driver for MAX7219/MAX7221
+ * Serially Interfaced, 8-Digit LED Display Drivers
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2017 Ruslan V. Uss <unclerus@gmail.com>
+ * BSD Licensed as described in the file LICENSE
+ */
+#include "max7219.h"
+#include <esp/spi.h>
+#include <esp/gpio.h>
+#include <string.h>
+
+#include "max7219_priv.h"
+
+#define SPI_BUS 1
+
+//#define MAX7219_DEBUG
+
+#ifdef MAX7219_DEBUG
+#include <stdio.h>
+#define debug(fmt, ...) printf("%s: " fmt "\n", "MAX7219", ## __VA_ARGS__)
+#else
+#define debug(fmt, ...)
+#endif
+
+#define ALL_CHIPS 0xff
+#define ALL_DIGITS 8
+
+#define REG_DIGIT_0      (1 << 8)
+#define REG_DECODE_MODE  (9 << 8)
+#define REG_INTENSITY    (10 << 8)
+#define REG_SCAN_LIMIT   (11 << 8)
+#define REG_SHUTDOWN     (12 << 8)
+#define REG_DISPLAY_TEST (15 << 8)
+
+#define VAL_CLEAR_BCD    0x0f
+#define VAL_CLEAR_NORMAL 0x00
+
+static const spi_settings_t bus_settings = {
+    .mode         = SPI_MODE0,
+    .freq_divider = SPI_FREQ_DIV_10M,
+    .msb          = true,
+    .minimal_pins = true,
+    .endianness   = SPI_BIG_ENDIAN
+};
+
+static void send(const max7219_display_t *disp, uint8_t chip, uint16_t value)
+{
+    uint16_t buf[MAX7219_MAX_CASCADE_SIZE] = { 0 };
+    if (chip == ALL_CHIPS)
+    {
+        for (uint8_t i = 0; i < disp->cascade_size; i++)
+            buf[i] = value;
+    }
+    else buf[chip] = value;
+
+    spi_settings_t old_settings;
+    spi_get_settings(SPI_BUS, &old_settings);
+    spi_set_settings(SPI_BUS, &bus_settings);
+    gpio_write(disp->cs_pin, false);
+
+    spi_transfer(SPI_BUS, buf, NULL, disp->cascade_size, SPI_16BIT);
+
+    gpio_write(disp->cs_pin, true);
+    spi_set_settings(SPI_BUS, &old_settings);
+}
+
+bool max7219_init(max7219_display_t *disp)
+{
+    if (!disp->cascade_size || disp->cascade_size > MAX7219_MAX_CASCADE_SIZE)
+    {
+        debug("Invalid cascade size %d", disp->cascade_size);
+        return false;
+    }
+
+    uint8_t max_digits = disp->cascade_size * ALL_DIGITS;
+    if (!disp->digits || disp->digits > max_digits)
+    {
+        debug("Invalid digits count %d, max %d", disp->cascade_size, max_digits);
+        return false;
+    }
+
+    gpio_enable(disp->cs_pin, GPIO_OUTPUT);
+    gpio_write(disp->cs_pin, true);
+
+    // Shutdown all chips
+    max7219_set_shutdown_mode(disp, true);
+    // Disable test
+    send(disp, ALL_CHIPS, REG_DISPLAY_TEST);
+    // Set max scan limit
+    send(disp, ALL_CHIPS, REG_SCAN_LIMIT | (ALL_DIGITS - 1));
+    // Set normal decode mode & clear display
+    max7219_set_decode_mode(disp, false);
+    // Set minimal brightness
+    max7219_set_brightness(disp, 0);
+    // Wake up
+    max7219_set_shutdown_mode(disp, false);
+
+    return true;
+}
+
+void max7219_set_decode_mode(max7219_display_t *disp, bool bcd)
+{
+    disp->bcd = bcd;
+    send(disp, ALL_CHIPS, REG_DECODE_MODE | (bcd ? 0xff : 0));
+    max7219_clear(disp);
+}
+
+void max7219_set_brightness(const max7219_display_t *disp, uint8_t value)
+{
+    send(disp, ALL_CHIPS, REG_INTENSITY | (value > MAX7219_MAX_BRIGHTNESS ? MAX7219_MAX_BRIGHTNESS : value));
+}
+
+void max7219_set_shutdown_mode(const max7219_display_t *disp, bool shutdown)
+{
+    send(disp, ALL_CHIPS, REG_SHUTDOWN | !shutdown);
+}
+
+bool max7219_set_digit(const max7219_display_t *disp, uint8_t digit, uint8_t val)
+{
+    if (digit >= disp->digits)
+    {
+        debug("Invalid digit: %d", digit);
+        return false;
+    }
+
+    if (disp->mirrored)
+        digit = disp->digits - digit - 1;
+
+    uint8_t c = digit / ALL_DIGITS;
+    uint8_t d = digit % ALL_DIGITS;
+
+    send(disp, c, (REG_DIGIT_0 + ((uint16_t)d << 8)) | val);
+
+    return true;
+}
+
+void max7219_clear(const max7219_display_t *disp)
+{
+    uint8_t val = disp->bcd ? VAL_CLEAR_BCD : VAL_CLEAR_NORMAL;
+    for (uint8_t i = 0; i < ALL_DIGITS; i++)
+        send(disp, ALL_CHIPS, (REG_DIGIT_0 + ((uint16_t)i << 8)) | val);
+}
+
+inline static uint8_t get_char(const max7219_display_t *disp, char c)
+{
+    if (disp->bcd)
+    {
+        if (c >= '0' && c <= '9')
+            return c - '0';
+        switch (c)
+        {
+            case '-':
+                return 0x0a;
+            case 'E':
+            case 'e':
+                return 0x0b;
+            case 'H':
+            case 'h':
+                return 0x0c;
+            case 'L':
+            case 'l':
+                return 0x0d;
+            case 'P':
+            case 'p':
+                return 0x0e;
+        }
+        return VAL_CLEAR_BCD;
+    }
+
+    return font_7seg[(c - 0x20) & 0x7f];
+}
+
+void max7219_draw_text(const max7219_display_t *disp, uint8_t pos, const char *s)
+{
+    while (s && pos < disp->digits)
+    {
+        uint8_t c = get_char(disp, *s);
+        if (*(s + 1) == '.')
+        {
+            c |= 0x80;
+            s++;
+        }
+        max7219_set_digit(disp, pos, c);
+        pos++;
+        s++;
+    }
+}