adc on/off

git-svn-id: https://svn.spreadspace.org/mur.sat@449 7de4ea59-55d0-425e-a1af-a3118ea81d4c

3 files changed, 17 insertions, 5 deletions

diff --git a/software/hhd70dongle/hhd70dongle.c b/software/hhd70dongle/hhd70dongle.c
index bc62dea..9bf3e8b 100644
--- a/software/hhd70dongle/hhd70dongle.c
+++ b/software/hhd70dongle/hhd70dongle.c
@@ -106,6 +106,8 @@ int main(void)
         write_buffer[3]='p';
         write_buffer[4]='s';
         write_buffer[5]=':';
+        adc_on();
+        _delay_ms(250);
         usb_rawhid_send((uint8_t*)"temp c1101:",255);
         debug_sprint_int16hex(write_buffer+6, c1101_measureTemp());
         usb_rawhid_send(write_buffer+6,255);
@@ -113,6 +115,7 @@ int main(void)
         usb_rawhid_send((uint8_t*)"temp atmega:",255);
         debug_sprint_int16hex(write_buffer+10, adc_read(ADCMUX_ADC12));
         usb_rawhid_send(write_buffer+10,255);
+        adc_off();
         _delay_ms(250);
         led_on();
         usb_rawhid_send((uint8_t*)"TX Data: String",255);
diff --git a/software/hhd70dongle/util.c b/software/hhd70dongle/util.c
index 2c358fa..56fe575 100644
--- a/software/hhd70dongle/util.c
+++ b/software/hhd70dongle/util.c
@@ -70,19 +70,26 @@ void reset(void)
   #endif 
 }
 
+//not switchin off adc produces slightly besser results
+void adc_on(void)
+{
+    ADCSRA = (1<<ADEN) | 0b00000111;                // enable ADC, Prescaler 1:128
+}
+
+void adc_off(void)
+{
+    ADCSRA &= ~(1<<ADEN);                           // disable ADC -> save power
+}
+
+
 uint8_t adc_read(uint8_t mux)
 {
     ADCSRB = (mux & 0x20);                          // select input 
     ADMUX = 0b11100000 | (mux & 0x1F);              // select input cont'd
                                                     // select internal 2.56V reference,
                                                     // result is left justified
-    ADCSRA = (1<<ADEN) | 0b00000111;                // enable ADC, Prescaler 1:128
-
     ADCSRA |= (1<<ADSC);                            // start the conversion
     while (ADCSRA & (1<<ADSC)) ;                    // wait for result
-
-    ADCSRA &= ~(1<<ADEN);                           // disable ADC -> save power
-
     return ADCH;
 }
 
diff --git a/software/hhd70dongle/util.h b/software/hhd70dongle/util.h
index 20068fd..4554af9 100644
--- a/software/hhd70dongle/util.h
+++ b/software/hhd70dongle/util.h
@@ -37,6 +37,8 @@
 #define ADCMUX_ADC12 0b00100100
 
 void reset(void);
+void adc_on(void);
+void adc_off(void);
 uint8_t adc_read(uint8_t mux);
 void debug_sprint_int16hex(uint8_t *buffer, int16_t num);