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main.cpp@1:20b452641613, 2014-06-12 (annotated)
- Committer:
- rutles
- Date:
- Thu Jun 12 09:03:02 2014 +0000
- Revision:
- 1:20b452641613
- Parent:
- 0:1913ea9baf30
Frequency counter with i2c slave.
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| rutles | 1:20b452641613 | 1 | // fc1114 - Frequency counter with i2c slave. |
| rutles | 0:1913ea9baf30 | 2 | // target: LPC1114FN28 |
| rutles | 0:1913ea9baf30 | 3 | |
| rutles | 0:1913ea9baf30 | 4 | #include "mbed.h" |
| rutles | 0:1913ea9baf30 | 5 | |
| rutles | 0:1913ea9baf30 | 6 | #define I2C_ADRS 0x70 |
| rutles | 0:1913ea9baf30 | 7 | |
| rutles | 0:1913ea9baf30 | 8 | DigitalOut led(dp28); |
| rutles | 0:1913ea9baf30 | 9 | I2CSlave slave(dp5, dp27); |
| rutles | 0:1913ea9baf30 | 10 | Ticker tick; |
| rutles | 0:1913ea9baf30 | 11 | |
| rutles | 1:20b452641613 | 12 | volatile uint32_t frq; |
| rutles | 0:1913ea9baf30 | 13 | |
| rutles | 0:1913ea9baf30 | 14 | void isr_tick(){ |
| rutles | 0:1913ea9baf30 | 15 | frq = LPC_TMR32B0->TC; |
| rutles | 0:1913ea9baf30 | 16 | LPC_TMR32B0->TC = 0; |
| rutles | 0:1913ea9baf30 | 17 | |
| rutles | 0:1913ea9baf30 | 18 | led = !led; |
| rutles | 0:1913ea9baf30 | 19 | } |
| rutles | 0:1913ea9baf30 | 20 | |
| rutles | 0:1913ea9baf30 | 21 | int main() { |
| rutles | 0:1913ea9baf30 | 22 | union { |
| rutles | 0:1913ea9baf30 | 23 | char b[4]; |
| rutles | 0:1913ea9baf30 | 24 | uint32_t w; |
| rutles | 0:1913ea9baf30 | 25 | } buf; |
| rutles | 0:1913ea9baf30 | 26 | char dummy[4]; |
| rutles | 0:1913ea9baf30 | 27 | |
| rutles | 1:20b452641613 | 28 | led = 1; |
| rutles | 0:1913ea9baf30 | 29 | tick.attach(&isr_tick, 1); |
| rutles | 0:1913ea9baf30 | 30 | |
| rutles | 0:1913ea9baf30 | 31 | LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 9);//TMR32B0 wakeup |
| rutles | 0:1913ea9baf30 | 32 | LPC_IOCON->PIO1_5 |= (1 << 1);// Set PIN14 as CT32B0_CAP0 |
| rutles | 0:1913ea9baf30 | 33 | LPC_IOCON->PIO1_5 |= (1 << 5);// Hysteresis enable |
| rutles | 0:1913ea9baf30 | 34 | LPC_TMR32B0->TCR = 2; // reset |
| rutles | 0:1913ea9baf30 | 35 | LPC_TMR32B0->CTCR = 1; // counter mode |
| rutles | 0:1913ea9baf30 | 36 | LPC_TMR32B0->CCR = 0; // Input Capture Disable) |
| rutles | 0:1913ea9baf30 | 37 | LPC_TMR32B0->PR = 0;// no prescale |
| rutles | 0:1913ea9baf30 | 38 | LPC_TMR32B0->TCR = 1; // start |
| rutles | 0:1913ea9baf30 | 39 | |
| rutles | 0:1913ea9baf30 | 40 | slave.address(I2C_ADRS << 1); |
| rutles | 0:1913ea9baf30 | 41 | |
| rutles | 0:1913ea9baf30 | 42 | while (1) { |
| rutles | 0:1913ea9baf30 | 43 | int i = slave.receive(); |
| rutles | 0:1913ea9baf30 | 44 | switch (i) { |
| rutles | 0:1913ea9baf30 | 45 | case I2CSlave::ReadAddressed: |
| rutles | 0:1913ea9baf30 | 46 | buf.w = frq; |
| rutles | 0:1913ea9baf30 | 47 | slave.write(buf.b, 4); |
| rutles | 0:1913ea9baf30 | 48 | break; |
| rutles | 0:1913ea9baf30 | 49 | case I2CSlave::WriteGeneral: |
| rutles | 0:1913ea9baf30 | 50 | slave.read(dummy, 4); |
| rutles | 0:1913ea9baf30 | 51 | break; |
| rutles | 0:1913ea9baf30 | 52 | case I2CSlave::WriteAddressed: |
| rutles | 0:1913ea9baf30 | 53 | slave.read(dummy, 4); |
| rutles | 0:1913ea9baf30 | 54 | break; |
| rutles | 0:1913ea9baf30 | 55 | } |
| rutles | 0:1913ea9baf30 | 56 | } |
| rutles | 0:1913ea9baf30 | 57 | } |