1 files changed, 67 insertions, 0 deletions
diff --git a/src/lib/adc.h b/src/lib/adc.h
new file mode 100644
index 0000000..41f975e
--- /dev/null
+++ b/src/lib/adc.h
@@ -0,0 +1,67 @@
+#ifndef _ADC_H_
+#define _ADC_H_
+#include <inttypes.h>
+#include "util.h"
+
+#ifdef __cplusplus
+extern "C"{
+#endif
+
+/* Notes:
+ * The maximum input impedance on each channel MUST be below .4kohms,
+ * or face the wrath of incorrect readings...
+ * This can be changed at the expense of sample time... see datasheet
+ *
+ * Need to up the sample time if otherwise... see datasheet */
+
+/* We'll only use ADC1 for now...  */
+#define ADC_BASE                 0x40012400
+#define ADC_SR                   *(volatile uint32_t*)(ADC_BASE + 0)
+#define ADC_CR1                  *(volatile uint32_t*)(ADC_BASE + 0x4)
+#define ADC_CR2                  *(volatile uint32_t*)(ADC_BASE + 0x8)
+#define ADC_SMPR1                *(volatile uint32_t*)(ADC_BASE + 0xC)
+#define ADC_SMPR2                *(volatile uint32_t*)(ADC_BASE + 0x10)
+#define ADC_SQR1                 *(volatile uint32_t*)(ADC_BASE + 0x2C)
+#define ADC_SQR3                 *(volatile uint32_t*)(ADC_BASE + 0x34)
+#define ADC_DR                   *(volatile uint32_t*)(ADC_BASE + 0x4C)
+
+#define CR2_EXTSEL_SWSTART       (0xE << 16)
+#define CR2_RSTCAL               (BIT(3))
+#define CR2_EXTTRIG              (BIT(20))
+
+/* Bit banded bits  */
+#define CR2_ADON_BIT             *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0x8, 0))
+#define CR2_CAL_BIT              *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0x8, 2))
+#define CR2_RSTCAL_BIT           *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0x8, 3))
+#define CR2_SWSTART_BIT          *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0x8 + 2, 6))
+#define SR_EOC_BIT               *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0, 1))
+
+#define NR_ANALOG_PINS           16
+
+/* Initialize ADC1 to do one-shot conversions  */
+void adc_init(void);
+
+/* Perform a single conversion on ADC[0-16],
+ * PRECONDITIONS:
+ *   adc initialized */
+static inline int adc_read(int channel) {
+    /* Set channel  */
+    ADC_SQR3 = channel;
+
+    /* Start the conversion  */
+    CR2_SWSTART_BIT = 1;
+
+    /* Wait for it to finish  */
+    while(SR_EOC_BIT == 0)
+        ;
+
+    return ADC_DR;
+}
+
+
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+#endif
+