more ADC / DAC / MCU progress...

- fixed t1616 Vref values getting clobbered sometimes,
  wrapped setting those in a #define'd function for ease and consistency
- moved some DAC definitions from hw/ to arch/ to reduce repetition
- fixed thefreeman's other builds
- switched from PWM_TOPS to PWM2_LEVELS (I'm trying to phase out _TOPS)

3 files changed, 40 insertions, 6 deletions

diff --git a/arch/attiny1616.c b/arch/attiny1616.c
index 330c809..2770d06 100644
--- a/arch/attiny1616.c
+++ b/arch/attiny1616.c
@@ -29,8 +29,7 @@ inline void clock_prescale_set(uint8_t n) {
 inline void mcu_set_admux_therm() {
     // put the ADC in temperature mode
     // attiny1616 datasheet section 30.3.2.6
-    VREF.CTRLA = (VREF.CTRLA & (~VREF_ADC0REFSEL_gm))
-                 | VREF_ADC0REFSEL_1V1_gc;  // Set Vbg ref to 1.1V
+    mcu_set_adc0_vref(VREF_ADC0REFSEL_1V1_gc);  // Set Vbg ref to 1.1V
     ADC0.MUXPOS = ADC_MUXPOS_TEMPSENSE_gc;  // read temperature
     ADC0.CTRLB = ADC_SAMPNUM_ACC4_gc;  // 10-bit result + 4x oversampling
     ADC0.CTRLC = ADC_SAMPCAP_bm
@@ -46,8 +45,7 @@ inline void mcu_set_admux_voltage() {
     ADC0.CTRLD |= ADC_INITDLY_DLY16_gc;
     #ifdef USE_VOLTAGE_DIVIDER  // measure an arbitrary pin
         // result = resolution * Vdiv / 1.1V
-        VREF.CTRLA = (VREF.CTRLA & (~VREF_ADC0REFSEL_gm))
-                     | VREF_ADC0REFSEL_1V1_gc;  // Set Vbg ref to 1.1V
+        mcu_set_adc0_vref(VREF_ADC0REFSEL_1V1_gc);  // Set Vbg ref to 1.1V
         ADC0.MUXPOS = ADMUX_VOLTAGE_DIVIDER;  // read the requested ADC pin
         ADC0.CTRLB = ADC_SAMPNUM_ACC4_gc;  // 12-bit result, 4x oversampling
         ADC0.CTRLC = ADC_SAMPCAP_bm
@@ -55,8 +53,7 @@ inline void mcu_set_admux_voltage() {
                    | ADC_REFSEL_INTREF_gc; // Use internal ADC reference
     #else  // measure VDD pin
         // result = resolution * 1.5V / Vbat
-        VREF.CTRLA = (VREF.CTRLA & (~VREF_ADC0REFSEL_gm))
-                     | VREF_ADC0REFSEL_1V5_gc;  // Set Vbg ref to 1.5V
+        mcu_set_adc0_vref(VREF_ADC0REFSEL_1V5_gc);  // Set Vbg ref to 1.5V
         ADC0.MUXPOS = ADC_MUXPOS_INTREF_gc;  // read internal reference
         ADC0.CTRLB = ADC_SAMPNUM_ACC4_gc;  // 12-bit result, 4x oversampling
         ADC0.CTRLC = ADC_SAMPCAP_bm
diff --git a/arch/attiny1616.h b/arch/attiny1616.h
index 57b0023..940973e 100644
--- a/arch/attiny1616.h
+++ b/arch/attiny1616.h
@@ -18,6 +18,8 @@ inline void mcu_clock_speed();
 // this should work, but needs further validation
 inline void clock_prescale_set(uint8_t n);
 
+// TODO: allow hwdef to define a base clock speed,
+//       and adjust these values accordingly
 typedef enum
 {
     // Actual clock is 20 MHz, but assume that 10 MHz is the top speed and work from there
@@ -34,8 +36,30 @@ typedef enum
 } clock_div_t;
 
 
+////////// DAC controls //////////
+
+#define DAC_LVL   DAC0.DATA    // 0 to 255, for 0V to Vref
+#define DAC_VREF  VREF.CTRLA   // 0.55V, 1.1V, 1.5V, 2.5V, or 4.3V
+
+// set only the relevant bits of the Vref register
+#define mcu_set_dac_vref(x) \
+    VREF.CTRLA = x | (VREF.CTRLA & (~VREF_DAC0REFSEL_gm));
+
+// Vref values
+// (for the DAC bits, not the ADC bits)
+#define V05   V055
+#define V055  VREF_DAC0REFSEL_0V55_gc
+#define V11   VREF_DAC0REFSEL_1V1_gc
+#define V25   VREF_DAC0REFSEL_2V5_gc
+#define V43   VREF_DAC0REFSEL_4V34_gc
+#define V15   VREF_DAC0REFSEL_1V5_gc
+
 ////////// ADC voltage / temperature //////////
 
+// set only the relevant bits of the Vref register
+#define mcu_set_adc0_vref(x) \
+    VREF.CTRLA = x | (VREF.CTRLA & (~VREF_ADC0REFSEL_gm));
+
 #define hwdef_set_admux_therm  mcu_set_admux_therm
 inline void mcu_set_admux_therm();
 
diff --git a/arch/avr32dd20.h b/arch/avr32dd20.h
index 82951de..09b4096 100644
--- a/arch/avr32dd20.h
+++ b/arch/avr32dd20.h
@@ -30,6 +30,19 @@ typedef enum
 } clock_div_t;
 
 
+////////// DAC controls //////////
+
+// main LED outputs
+#define DAC_LVL   DAC0_DATA    // 0 to 1023, for 0V to Vref
+#define DAC_VREF  VREF_DAC0REF // 1.024V, 2.048V, 4.096V, or 2.5V
+
+// Vref values (suitable for DAC and ADC0)
+#define V10   VREF_REFSEL_1V024_gc
+#define V20   VREF_REFSEL_2V048_gc
+#define V25   VREF_REFSEL_2V500_gc
+#define V40   VREF_REFSEL_4V096_gc
+
+
 ////////// ADC voltage / temperature //////////
 
 #define hwdef_set_admux_therm  mcu_set_admux_therm