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

This places the 5v reference samples in an array parallel to the basic
ADC values. It doesn't do anything with the values, just stores them.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/ao.h b/src/ao.h
index abac22a31e619322b644e49264022c52c3d63c40..cef20e61731e869a5a3a517d7a2186cf9fa5c694 100644 (file)
--- a/src/ao.h
+++ b/src/ao.h
@@ -163,6 +163,11 @@ struct ao_adc {
 #endif
 
 #if HAS_ADC
+
+#ifndef HAS_ACCEL_REF
+#error Please define HAS_ACCEL_REF
+#endif
+
 /*
  * ao_adc.c
  */
@@ -178,6 +183,9 @@ struct ao_adc {
  */
 extern volatile __xdata struct ao_adc  ao_adc_ring[AO_ADC_RING];
 extern volatile __data uint8_t         ao_adc_head;
+#if HAS_ACCEL_REF
+extern volatile __xdata uint16_t       ao_accel_ref[AO_ADC_RING];
+#endif
 
 /* Trigger a conversion sequence (called from the timer interrupt) */
 void

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();

diff --git a/src/ao_pins.h b/src/ao_pins.h
index 9446964e1f02b7f8427386414157e25ed421638c..2c5b9db5ca749a34f7f7d9f3884c53b848906dae 100644 (file)
--- a/src/ao_pins.h
+++ b/src/ao_pins.h
@@ -31,6 +31,7 @@
        #define AO_LED_RED              1
        #define LEDS_AVAILABLE          (AO_LED_RED)
        #define HAS_EXTERNAL_TEMP       0
+       #define HAS_ACCEL_REF           0
 #endif
 
 #if defined(TELEMETRUM_V_1_1)
@@ -46,6 +47,7 @@
        #define AO_LED_RED              1
        #define LEDS_AVAILABLE          (AO_LED_RED)
        #define HAS_EXTERNAL_TEMP       0
+       #define HAS_ACCEL_REF           1
        #define SPI_CS_ON_P1            1
        #define SPI_CS_ON_P0            0
        #define M25_CS_MASK             0x02    /* CS0 is P1_1 */
@@ -81,6 +83,7 @@
        #define AO_LED_GREEN            1
        #define LEDS_AVAILABLE          (AO_LED_RED|AO_LED_GREEN)
        #define HAS_EXTERNAL_TEMP       1
+       #define HAS_ACCEL_REF           0
        #define SPI_CS_ON_P1            1
        #define SPI_CS_ON_P0            0
 #endif