David Buck
ADC_setup.cpp@0:d322a5241da8, 2009-12-16 (annotated)
- Committer:
- Kaikestu
- Date:
- Wed Dec 16 12:04:23 2009 +0000
- Revision:
- 0:d322a5241da8
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| Kaikestu | 0:d322a5241da8 | 1 | // ADC_setup.cpp |
| Kaikestu | 0:d322a5241da8 | 2 | |
| Kaikestu | 0:d322a5241da8 | 3 | #include "header.h" |
| Kaikestu | 0:d322a5241da8 | 4 | /***************************************************** |
| Kaikestu | 0:d322a5241da8 | 5 | variables and defines |
| Kaikestu | 0:d322a5241da8 | 6 | ****************************************************/ |
| Kaikestu | 0:d322a5241da8 | 7 | |
| Kaikestu | 0:d322a5241da8 | 8 | int ADC_channel=1; // ADC channel 1 |
| Kaikestu | 0:d322a5241da8 | 9 | |
| Kaikestu | 0:d322a5241da8 | 10 | /***************************************************** |
| Kaikestu | 0:d322a5241da8 | 11 | subroutines |
| Kaikestu | 0:d322a5241da8 | 12 | *****************************************************/ |
| Kaikestu | 0:d322a5241da8 | 13 | void ADC_init(){ |
| Kaikestu | 0:d322a5241da8 | 14 | |
| Kaikestu | 0:d322a5241da8 | 15 | PINSEL1=0x00010000; //set AD0.1 pin to 0000 0000 0000 0001 0000 0000 0000 0000 = ADC |
| Kaikestu | 0:d322a5241da8 | 16 | PCONP |= (1 << 12); // enable ADC clock |
| Kaikestu | 0:d322a5241da8 | 17 | AD0CR = (1 << ADC_channel) // channel 1 |
| Kaikestu | 0:d322a5241da8 | 18 | | (4 << 8) // This gives us 3MHz |
| Kaikestu | 0:d322a5241da8 | 19 | | (0 << 16) // BURST = 0, software control |
| Kaikestu | 0:d322a5241da8 | 20 | | (0 << 17) // CLKS = 0 (11-bits) |
| Kaikestu | 0:d322a5241da8 | 21 | | (1 << 21) // PDN = 1 |
| Kaikestu | 0:d322a5241da8 | 22 | | (0 << 22) // TEST1:0 = 00 |
| Kaikestu | 0:d322a5241da8 | 23 | | (1 << 24) // START = 1 start A/D conversion |
| Kaikestu | 0:d322a5241da8 | 24 | | (0 << 27); // EDGE = 0 (CAP/MAT singal falling,trigger A/D conversion) |
| Kaikestu | 0:d322a5241da8 | 25 | } |
| Kaikestu | 0:d322a5241da8 | 26 | float ADC_read() { |
| Kaikestu | 0:d322a5241da8 | 27 | |
| Kaikestu | 0:d322a5241da8 | 28 | int data; |
| Kaikestu | 0:d322a5241da8 | 29 | |
| Kaikestu | 0:d322a5241da8 | 30 | // start A/D conversion on channel |
| Kaikestu | 0:d322a5241da8 | 31 | AD0CR &= (AD0CR & 0xFFFFFF00); |
| Kaikestu | 0:d322a5241da8 | 32 | AD0CR |= (1 << ADC_channel) | (1 << 24); |
| Kaikestu | 0:d322a5241da8 | 33 | |
| Kaikestu | 0:d322a5241da8 | 34 | delay_l(); |
| Kaikestu | 0:d322a5241da8 | 35 | |
| Kaikestu | 0:d322a5241da8 | 36 | // wait for it to finish by polling the ADC DONE bit |
| Kaikestu | 0:d322a5241da8 | 37 | while((AD0GDR & 0x80000000) == 0) |
| Kaikestu | 0:d322a5241da8 | 38 | { |
| Kaikestu | 0:d322a5241da8 | 39 | } |
| Kaikestu | 0:d322a5241da8 | 40 | |
| Kaikestu | 0:d322a5241da8 | 41 | // get the data and stop the adc |
| Kaikestu | 0:d322a5241da8 | 42 | data = AD0GDR; |
| Kaikestu | 0:d322a5241da8 | 43 | AD0CR &= 0xF8FFFFFF; |
| Kaikestu | 0:d322a5241da8 | 44 | |
| Kaikestu | 0:d322a5241da8 | 45 | // shift data and mask to give 8-bit ADC value |
| Kaikestu | 0:d322a5241da8 | 46 | data=(data>>8)&0x00000FF; |
| Kaikestu | 0:d322a5241da8 | 47 | return data; |
| Kaikestu | 0:d322a5241da8 | 48 | } |