Rev 19 | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed
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| 52 | // + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
52 | // + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 53 | // + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
53 | // + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 54 | // + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
54 | // + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 55 | // + POSSIBILITY OF SUCH DAMAGE. |
55 | // + POSSIBILITY OF SUCH DAMAGE. |
| 56 | // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
56 | // ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| 57 | //#include <stdlib.h> |
57 | #include <util/delay.h> |
| 58 | #include "analog.h" |
58 | #include "analog.h" |
| Line -... | Line 59... | ||
| - | 59 | ||
| - | 60 | uint8_t AccPresent = 0; |
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| 59 | 61 | ||
| 60 | void ADC_Init(void) |
62 | void ADC_Init(void) |
| - | 63 | { |
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| - | 64 | // The analog inputs have a VREF of 5V and a resolution of 10 bit (0...1024 counts) |
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| - | 65 | // i.e. 4.88mV/Count |
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| 61 | { |
66 | |
| 62 | // set PortC 0,1,2,3 as input |
67 | // set PortC 0,1,2,3 as input |
| 63 | DDRC &= ~((1<<DDC3)|(1<<DDC2)|(1<<DDC1)|(1<<DDC0)); |
68 | DDRC &= ~((1<<DDC3)|(1<<DDC2)|(1<<DDC1)|(1<<DDC0)); |
| 64 | // set PortC 0,1,2,3 and 6,7 as tri state |
69 | // set PortC 0,1,2,3 as tri state |
| Line 65... | Line 70... | ||
| 65 | PORTC &= ~((1<<PORTC3)|(1<<PORTC2)|(1<<PORTC1)|(1<<PORTC0)); |
70 | PORTC &= ~((1<<PORTC3)|(1<<PORTC2)|(1<<PORTC1)|(1<<PORTC0)); |
| 66 | 71 | ||
| 67 | // port PD5 and PD6 control the current direction of the test coils of the sensors |
72 | // port PD5 and PD6 control the current direction of the test coils of the sensors |
| Line 76... | Line 81... | ||
| 76 | ADCSRA &= ~((1<<ADSC)|(1<<ADATE)|(1<<ADIE)); |
81 | ADCSRA &= ~((1<<ADSC)|(1<<ADATE)|(1<<ADIE)); |
| 77 | // Enable ADC (ADEN = 1) with SYSCLK/128 (ADPS2 = 1, ADPS1 = 1, ADPS0 = 1) and clear ready flag (ADIF = 1) |
82 | // Enable ADC (ADEN = 1) with SYSCLK/128 (ADPS2 = 1, ADPS1 = 1, ADPS0 = 1) and clear ready flag (ADIF = 1) |
| 78 | ADCSRA |= ((1<<ADEN)|(1<<ADIF)|(1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0)); |
83 | ADCSRA |= ((1<<ADEN)|(1<<ADIF)|(1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0)); |
| 79 | ADMUX = 0x00; // select ADC0 |
84 | ADMUX = 0x00; // select ADC0 |
| 80 | ADCSRA |= (1<<ADSC); // start conversion |
85 | ADCSRA |= (1<<ADSC); // start conversion |
| - | 86 | ||
| - | 87 | ||
| - | 88 | // Check if acceleration sensor is present |
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| - | 89 | // The output of the LIS3L02AL (MK3MAG V1.0) and the LIS344ALH (MK3MAG V1.1) is Vdd/5 +/- 10% per 1g. |
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| - | 90 | // The Vdd is 3.0V at this board therefore the sensitivity is 0.6V/g +/-10% that corresponds to 123 counts. |
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| - | 91 | // The offsets at 0g is VDD/2 (1.5V) that is 307 counts. |
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| - | 92 | // that yields to an ADC range of 184 to 430 counts. |
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| - | 93 | ||
| - | 94 | // pullup PC2(AccX) and PC3 (AccY) |
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| - | 95 | PORTC |= ((1<<PORTC3)|(1<<PORTC2)); |
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| - | 96 | _delay_ms(10.0); |
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| - | 97 | // if ADC2 and ADC 3 is larger than 1000 counts (4.88V) no load is at the pins |
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| - | 98 | if((ADC_GetValue(ADC2) > 1000) && (ADC_GetValue(ADC3) > 1000)) AccPresent = 0; |
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| - | 99 | else AccPresent = 1; |
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| - | 100 | // set port back to tristate |
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| - | 101 | PORTC &= ~((1<<PORTC3)|(1<<PORTC2)); |
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| 81 | } |
102 | } |
| Line 82... | Line 103... | ||
| 82 | 103 | ||
| 83 | 104 | ||
| 84 | uint16_t ADC_GetValue(ADChannel_t channel) |
105 | uint16_t ADC_GetValue(ADChannel_t channel) |
| 85 | { |
106 | { |
| 86 | uint16_t value = 0; |
107 | uint16_t value = 0; |
| 87 | ADMUX = channel; // set muxer bits |
108 | ADMUX = channel; // set muxer bits |
| 88 | ADCSRA |= (1<<ADIF); // clear ready-flag |
109 | ADCSRA |= (1<<ADIF); // clear ready-flag |
| 89 | ADCSRA |= (1<<ADSC); // start conversion |
110 | ADCSRA |= (1<<ADSC); // start conversion |
| 90 | while (((ADCSRA & (1<<ADIF)) == 0)); // wait for end of conversion |
111 | while (((ADCSRA & (1<<ADIF)) == 0)); // wait for end of conversion |
| 91 | value = ADCW; // read adc result |
112 | value = ADCW; // read adc result |