Initial Release

2021-01-20 10:49:34 -06:00
commit 46078742c7
245 changed files with 21157 additions and 0 deletions
--- a/gpio/hello_7segment/hello_7segment.c
+++ b/gpio/hello_7segment/hello_7segment.c
@@ -0,0 +1,95 @@
+/**
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+
+/*
+  Our 7 Segment display has pins as follows:
+
+  --A--
+  F   B
+  --G--
+  E   C
+  --D--
+
+  By default we are allocating GPIO 2 to A, 3 to B etc.
+  So, connect GOIP 2 to pin A on the 7 segment LED display etc. Don't forget
+  the appropriate resistors, best to use one for each segment!
+
+  Connect button so that pressing the switch connects the GPIO 9 (default) to
+  ground (pull down)
+*/
+
+#define FIRST_GPIO 2
+#define BUTTON_GPIO (FIRST_GPIO+7)
+
+// This array converts a number 0-9 to a bit pattern to send to the GPIO's
+int bits[10] = {
+        0x3f,  // 0
+        0x06,  // 1
+        0x5b,  // 2
+        0x4f,  // 3
+        0x66,  // 4
+        0x6d,  // 5
+        0x7d,  // 6
+        0x07,  // 7
+        0x7f,  // 8
+        0x67   // 9
+};
+
+// tag::hello_gpio[]
+int main() {
+    stdio_init_all();
+    printf("Hello, 7segment - press button to count down!\n");
+
+    // We could use gpio_set_dir_out_masked() here
+    for (int gpio = FIRST_GPIO; gpio < FIRST_GPIO + 7; gpio++) {
+        gpio_init(gpio);
+        gpio_set_dir(gpio, GPIO_OUT);
+        // Our bitmap above has a bit set where we need an LED on, BUT, we are pulling low to light
+        // so invert our output
+        gpio_set_outover(gpio, GPIO_OVERRIDE_INVERT);
+    }
+
+    gpio_init(BUTTON_GPIO);
+    gpio_set_dir(BUTTON_GPIO, GPIO_IN);
+    // We are using the button to pull down to 0v when pressed, so ensure that when
+    // unpressed, it uses internal pull ups. Otherwise when unpressed, the input will
+    // be floating.
+    gpio_pull_up(BUTTON_GPIO);
+
+    int val = 0;
+    while (true) {
+        // Count upwards or downwards depending on button input
+        // We are pulling down on switch active, so invert the get to make
+        // a press count downwards
+        if (!gpio_get(BUTTON_GPIO)) {
+            if (val == 9) {
+                val = 0;
+            } else {
+                val++;
+            }
+        } else if (val == 0) {
+            val = 9;
+        } else {
+            val--;
+        }
+
+        // We are starting with GPIO 2, our bitmap starts at bit 0 so shift to start at 2.
+        int32_t mask = bits[val] << FIRST_GPIO;
+
+        // Set all our GPIO's in one go!
+        // If something else is using GPIO, we might want to use gpio_put_masked()
+        gpio_set_mask(mask);
+        sleep_ms(250);
+        gpio_clr_mask(mask);
+    }
+
+    return 0;
+}
+// end::hello_gpio[]