JavaScript BigBanging SPI MAX7219

js/spi_bitbang/max7219.js

@@ -0,0 +1,69 @@
+let gpio = require("gpio");
+let gpio_spi_mosi = "PA7";
+let gpio_spi_sck = "PB3";
+let gpio_spi_cs = "PA4";
+gpio.init(gpio_spi_mosi, "outputPushPull", "none");
+gpio.init(gpio_spi_sck, "outputPushPull", "none");
+gpio.init(gpio_spi_cs, "outputPushPull", "none");
+
+function leds(addr, data) {
+    gpio.write(gpio_spi_mosi, false);
+    gpio.write(gpio_spi_sck, false);
+    gpio.write(gpio_spi_cs, false);
+
+    let mask = 0x80;
+    for (let i = 0; i < 8; i++) {
+        gpio.write(gpio_spi_mosi, (addr & mask) !== 0);
+        gpio.write(gpio_spi_sck, true);
+        gpio.write(gpio_spi_sck, false);
+        mask >>= 1;
+    }
+
+    for (let i = 0; i < 8; i++) {
+        gpio.write(gpio_spi_mosi, data[i] !== ' ' && data[i] !== '0');
+        gpio.write(gpio_spi_sck, true);
+        gpio.write(gpio_spi_sck, false);
+    }
+
+    gpio.write(gpio_spi_cs, true);
+    gpio.write(gpio_spi_mosi, true);
+    gpio.write(gpio_spi_sck, true);
+}
+
+
+// Initialize MAX7219 device
+leds(0xFF, "00000000");
+leds(0x0C, "00000001");
+leds(0x09, "00000000");
+leds(0x0A, "00000111");
+leds(0x0B, "00000111");
+
+for (let loop_counter = 0; loop_counter < 10; loop_counter++) {
+    // Draw the pattern (0 = off, 1 = on)
+    leds(0x1, "  ****  ");
+    leds(0x2, " *    * ");
+    leds(0x3, "*      *");
+    leds(0x4, "*      *");
+    leds(0x5, "*      *");
+    leds(0x6, "*      *");
+    leds(0x7, " *    * ");
+    leds(0x8, "  ****  ");
+
+    delay(250); // Wait 1/4 second
+
+    // Draw the pattern (0 = off, 1 = on)
+    leds(0x1, "  ****  ");
+    leds(0x2, " *    * ");
+    leds(0x3, "*      *");
+    leds(0x4, "* *  * *");
+    leds(0x5, "*      *");
+    leds(0x6, "* **** *");
+    leds(0x7, " *    * ");
+    leds(0x8, "  ****  ");
+
+    delay(250); // Wait 1/4 second
+}
+
+gpio.init(gpio_spi_mosi, "analog", "none");
+gpio.init(gpio_spi_sck, "analog", "none");
+gpio.init(gpio_spi_cs, "analog", "none");