basic working dac implementation

1 files changed, 67 insertions, 0 deletions

diff --git a/libmaple/dac.c b/libmaple/dac.c
new file mode 100644
index 0000000..b9c7d63
--- /dev/null
+++ b/libmaple/dac.c
@@ -0,0 +1,67 @@
+
+/* *****************************************************************************
+ * The MIT License
+ *
+ * Copyright (c) 2010 Bryan Newbold.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ * ****************************************************************************/
+
+#include "libmaple.h"
+#include "rcc.h"
+#include "gpio.h"
+#include "dac.h"
+
+// Only one, so global to this file
+DAC_Map *dac = (DAC_Map*)(DAC_BASE);
+
+// This numbering follows the registers (1-indexed)
+#define DAC_CHA     1
+#define DAC_CHB     2
+
+// Sets up the DAC peripheral
+void dac_init(void) {
+
+    // First turn on the clock
+    rcc_enable_clk_dac();
+
+    // Then setup ANALOG mode on PA4 and PA5 
+    gpio_set_mode(GPIOA_BASE,  4, CNF_INPUT_ANALOG);
+    gpio_set_mode(GPIOA_BASE,  5, CNF_INPUT_ANALOG);
+
+    // Then do register stuff.
+    // Default does no triggering, and buffered output, so all good.
+    dac->CR |= DAC_CR_EN1;
+    dac->CR |= DAC_CR_EN2;
+
+}
+
+void dac_write(uint8 chan, uint16 val) {
+
+    switch(chan) {
+        case DAC_CHA:
+            dac->DHR12R1 = 0x0FFF & val;
+            break;
+        case DAC_CHB:
+            dac->DHR12R2 = 0x0FFF & val;
+            break;
+        default:    
+            ASSERT(0);  // Shouldn't get here
+    }
+}