altos: Sample the accelerometer reference voltage on v1.1 boards

[fw/altos] / src / ao_adc.c

diff --git a/src/ao_adc.c b/src/ao_adc.c
index f577b4582afe02ca838500b2d3d9e5e344612835..3adf9b2e70277526e252770c7071dec7a400d0b1 100644 (file)
--- a/src/ao_adc.c
+++ b/src/ao_adc.c
@@ -19,12 +19,19 @@
 #include "ao_pins.h"
 
 volatile __xdata struct ao_adc ao_adc_ring[AO_ADC_RING];
+#if HAS_ACCEL_REF
+volatile __xdata uint16_t      ao_accel_ref[AO_ADC_RING];
+#endif
 volatile __data uint8_t                ao_adc_head;
 
 void
 ao_adc_poll(void)
 {
+#if HAS_ACCEL_REF
+       ADCCON3 = ADCCON3_EREF_VDD | ADCCON3_EDIV_512 | 2;
+#else
        ADCCON3 = ADCCON3_EREF_VDD | ADCCON3_EDIV_512 | 0;
+#endif
 }
 
 void
@@ -41,20 +48,29 @@ ao_adc_isr(void) __interrupt 1
        uint8_t __xdata *a;
 
        sequence = (ADCCON2 & ADCCON2_SCH_MASK) >> ADCCON2_SCH_SHIFT;
-       if (sequence == ADCCON3_ECH_TEMP)
-               sequence = 2;
-       a = (uint8_t __xdata *) (&ao_adc_ring[ao_adc_head].accel + sequence);
+#if HAS_ACCEL_REF
+       if (sequence == 2) {
+               a = (uint8_t __xdata *) (&ao_accel_ref[ao_adc_head]);
+               sequence = 0;
+       } else
+#endif
+       {
+               if (sequence == ADCCON3_ECH_TEMP)
+                       sequence = 2;
+               a = (uint8_t __xdata *) (&ao_adc_ring[ao_adc_head].accel + sequence);
+               sequence++;
+       }
        a[0] = ADCL;
        a[1] = ADCH;
-       if (sequence < 5) {
+       if (sequence < 6) {
 #if HAS_EXTERNAL_TEMP == 0
                /* start next channel conversion */
                /* v0.2 replaces external temp sensor with internal one */
-               if (sequence == 1)
+               if (sequence == 2)
                        ADCCON3 = ADCCON3_EREF_1_25 | ADCCON3_EDIV_512 | ADCCON3_ECH_TEMP;
                else
 #endif
-                       ADCCON3 = ADCCON3_EREF_VDD | ADCCON3_EDIV_512 | (sequence + 1);
+                       ADCCON3 = ADCCON3_EREF_VDD | ADCCON3_EDIV_512 | sequence;
        } else {
                /* record this conversion series */
                ao_adc_ring[ao_adc_head].tick = ao_time();