From 8391b13848fc9dea3548cc1d78965792ad600324 Mon Sep 17 00:00:00 2001
From: Peter Wu <lekensteyn@gmail.com>
Date: Fri, 9 Dec 2011 10:31:19 +0000
Subject: Add some tests

---
 tests/enable-leds.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 tests/enable-leds.c

(limited to 'tests/enable-leds.c')

diff --git a/tests/enable-leds.c b/tests/enable-leds.c
new file mode 100644
index 0000000..315f665
--- /dev/null
+++ b/tests/enable-leds.c
@@ -0,0 +1,57 @@
+/*
+ * File:   enable_digit.c
+ * Author: Peter Wu
+ */
+
+/**
+ * Determines the bitmask necessary for enabling LED segments on a LED
+ * @param number The number to be displayed
+ * @return The segment bits to be enabled
+ */
+static int segment_mask(int number) {
+    switch (number) {
+        case 0:
+            return 0x7e;// 01111110
+        case 1:
+            return 0x30;// 00110000
+        case 2:
+            return 0x6d;// 01101101
+        case 3:
+            return 0x79;// 01111001
+        case 4:
+            return 0x33;// 00110011
+        case 5:
+            return 0x5b;// 01011011
+        case 6:
+            return 0x5f;// 01011111
+        case 7:
+            return 0x70;// 01110000
+        case 8:
+            return 0x7f;// 01111111
+        case 9:
+            return 0x7b;// 01111011
+    }
+    // in case you do not pass the right arguments, turn everything on
+    return 0xff;
+}
+
+/**
+ * Displays a digit at a certain index
+ * @param digit The digit to be displayed (between 0 and 9 inclusive)
+ * @param index The number of the LED segment to be enabled, counting from the
+ * right side. index 0 means that all LEDS are disabled. The n-th LED can be
+ * selected with index n with 1 <= n <= 6
+ */
+void enable_digit(int digit, int index) {
+    int *digitp = (int*)-7;
+    int *segmentp = (int*)-8;
+
+    // first set the segments to be enabled
+    *segmentp = segment_mask(digit);
+    // enable bit "index" if index > 0
+    *digitp = index ? 1 << (index - 1) : 0;
+}
+int main() {
+    enable_digit(0, 0);
+    return 0;
+}
-- 
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