Simon Ford
main.cpp@0:3e987e5f426b, 2010-01-04 (annotated)
- Committer:
- simon
- Date:
- Mon Jan 04 14:18:40 2010 +0000
- Revision:
- 0:3e987e5f426b
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| simon | 0:3e987e5f426b | 1 | // analog input p20 (ADC0[5], pin 3) test |
| simon | 0:3e987e5f426b | 2 | |
| simon | 0:3e987e5f426b | 3 | #include "mbed.h" |
| simon | 0:3e987e5f426b | 4 | |
| simon | 0:3e987e5f426b | 5 | int main() { |
| simon | 0:3e987e5f426b | 6 | |
| simon | 0:3e987e5f426b | 7 | // power on, clk divider /4 |
| simon | 0:3e987e5f426b | 8 | LPC_SC->PCONP |= (1 << 12); |
| simon | 0:3e987e5f426b | 9 | LPC_SC->PCLKSEL0 &= ~(0x3 << 24); |
| simon | 0:3e987e5f426b | 10 | |
| simon | 0:3e987e5f426b | 11 | // software-controlled ADC settings |
| simon | 0:3e987e5f426b | 12 | LPC_ADC->ADCR = (0 << 0) // SEL: 0 = no channels selected |
| simon | 0:3e987e5f426b | 13 | | (25 << 8) // CLKDIV: PCLK max ~= 25MHz, /25 to give safe 1MHz |
| simon | 0:3e987e5f426b | 14 | | (0 << 16) // BURST: 0 = software control |
| simon | 0:3e987e5f426b | 15 | | (0 << 17) // CLKS: not applicable |
| simon | 0:3e987e5f426b | 16 | | (1 << 21) // PDN: 1 = operational |
| simon | 0:3e987e5f426b | 17 | | (0 << 24) // START: 0 = no start |
| simon | 0:3e987e5f426b | 18 | | (0 << 27); // EDGE: not applicable |
| simon | 0:3e987e5f426b | 19 | |
| simon | 0:3e987e5f426b | 20 | // setup P1_31 as sel 3 (ADC), mode 2 (no pull) |
| simon | 0:3e987e5f426b | 21 | LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 30); |
| simon | 0:3e987e5f426b | 22 | LPC_PINCON->PINSEL3 |= (unsigned int)0x3 << 30; |
| simon | 0:3e987e5f426b | 23 | |
| simon | 0:3e987e5f426b | 24 | LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 30); |
| simon | 0:3e987e5f426b | 25 | LPC_PINCON->PINMODE3 |= (unsigned int)0x2 << 30; |
| simon | 0:3e987e5f426b | 26 | |
| simon | 0:3e987e5f426b | 27 | while(1) { |
| simon | 0:3e987e5f426b | 28 | // Select channel and start conversion |
| simon | 0:3e987e5f426b | 29 | LPC_ADC->ADCR &= ~0xFF; |
| simon | 0:3e987e5f426b | 30 | LPC_ADC->ADCR |= 1 << 5; // ADC0[5] |
| simon | 0:3e987e5f426b | 31 | LPC_ADC->ADCR |= 1 << 24; |
| simon | 0:3e987e5f426b | 32 | |
| simon | 0:3e987e5f426b | 33 | // Repeatedly get the sample data until DONE bit |
| simon | 0:3e987e5f426b | 34 | unsigned int data; |
| simon | 0:3e987e5f426b | 35 | do { |
| simon | 0:3e987e5f426b | 36 | data = LPC_ADC->ADGDR; |
| simon | 0:3e987e5f426b | 37 | } while ((data & ((unsigned int)1 << 31)) == 0); |
| simon | 0:3e987e5f426b | 38 | |
| simon | 0:3e987e5f426b | 39 | // Stop conversion |
| simon | 0:3e987e5f426b | 40 | LPC_ADC->ADCR &= ~(1 << 24); |
| simon | 0:3e987e5f426b | 41 | |
| simon | 0:3e987e5f426b | 42 | printf("0x%3X\n", data); |
| simon | 0:3e987e5f426b | 43 | } |
| simon | 0:3e987e5f426b | 44 | } |