currentsensor.h

#ifndef CURRENTSENSOR_H
#define CURRENTSENSOR_H

//HIPEAC+EWSN demo stuff -- begin
void initAdc()
{
    {
        miosix::FastInterruptDisableLock dLock;
        CMU->HFPERCLKEN0|=CMU_HFPERCLKEN0_ADC0
                        | CMU_HFPERCLKEN0_TIMER0
                        | CMU_HFPERCLKEN0_PRS
                        | CMU_HFPERCLKEN0_USART0;
    }
    
    //HACK: to make usart work here it is necessary to disable it from the bsp
    //and replace the content of Rtc::absoluteSleep() with a call
    //to absoluteWait()
    
    //Set-up USART
    unsigned int baudrate=115200;
    typedef miosix::Gpio<GPIOE_BASE,10> u0tx;
    typedef miosix::Gpio<GPIOE_BASE,11> u0rx;
    u0tx::mode(miosix::Mode::OUTPUT_HIGH);
    u0rx::mode(miosix::Mode::INPUT_PULL_UP_FILTER);
    USART0->IRCTRL=0; //USART0 also has IrDA mode
    USART0->CTRL=USART_CTRL_TXBIL_HALFFULL; //Use the buffer more efficiently
    USART0->FRAME=USART_FRAME_STOPBITS_ONE
            | USART_FRAME_PARITY_NONE
            | USART_FRAME_DATABITS_EIGHT;
    USART0->TRIGCTRL=0;
    USART0->INPUT=0;
    USART0->I2SCTRL=0;
    USART0->ROUTE=USART_ROUTE_LOCATION_LOC0 //Default location
              | USART_ROUTE_TXPEN         //Enable TX pin
              | USART_ROUTE_RXPEN;        //Enable RX pin
    unsigned int periphClock=SystemHFClockGet()/(1<<(CMU->HFPERCLKDIV & 0xf));
    //The number we need is periphClock/baudrate/16-1, but with two bits of
    //fractional part. We divide by 2 instead of 16 to have 3 bit of fractional
    //part. We use the additional fractional bit to add one to round towards
    //the nearest. This gets us a little more precision. Then we subtract 8
    //which is one with three fractional bits. Then we shift to fit the integer
    //part in bits 20:8 and the fractional part in bits 7:6, masking away the
    //third fractional bit. Easy, isn't it? Not quite.
    USART0->CLKDIV=((((periphClock/baudrate/2)+1)-8)<<5) & 0x1fffc0;
    USART0->CMD=USART_CMD_CLEARRX
            | USART_CMD_CLEARTX
            | USART_CMD_TXTRIDIS
            | USART_CMD_RXBLOCKDIS
            | USART_CMD_MASTEREN
            | USART_CMD_TXEN;
//             | USART_CMD_RXEN;
    
    //Set up PRS
    PRS->CH[0].CTRL=PRS_CH_CTRL_ASYNC_DEFAULT
                  | PRS_CH_CTRL_EDSEL_OFF
                  | PRS_CH_CTRL_SOURCESEL_TIMER0
                  | PRS_CH_CTRL_SIGSEL_TIMER0OF;
    
    //Set up timer
    TIMER0->CTRL=TIMER_CTRL_PRESC_DIV1
               | TIMER_CTRL_CLKSEL_PRESCHFPERCLK
               | TIMER_CTRL_MODE_UP;
    TIMER0->TOP=9600-1; //5KHz
               
    
    //Set up ADC
    ADC0->CTRL=ADC_CTRL_OVSRSEL_X4096              //Not used
             | ((48-1)<<16)                        //TIMEBASE 48MHz / 48 =  1MHz
             | ((4-1)<<8)                          //PRESC    48MHz / 4  = 12MHz
             | ADC_CTRL_LPFMODE_RCFILT             //Add some filtering
             | ADC_CTRL_TAILGATE_DEFAULT           //No tailgate
             | ADC_CTRL_WARMUPMODE_KEEPSCANREFWARM;//1us warmup before conversion
    ADC0->SINGLECTRL=ADC_SINGLECTRL_PRSSEL_PRSCH0
                   | ADC_SINGLECTRL_PRSEN          //Trigger conversion on PRS0
                   | ADC_SINGLECTRL_AT_1CYCLE
                   | ADC_SINGLECTRL_REF_1V25
                   | ADC_SINGLECTRL_INPUTSEL_CH3
                   | ADC_SINGLECTRL_RES_12BIT
                   | ADC_SINGLECTRL_ADJ_RIGHT
                   | ADC_SINGLECTRL_DIFF_DEFAULT
                   | ADC_SINGLECTRL_REP_DEFAULT;
    ADC0->IEN=ADC_IEN_SINGLE;
    NVIC_SetPriority(ADC0_IRQn,15);
    NVIC_EnableIRQ(ADC0_IRQn);
    
    //Start timer
    TIMER0->CMD=TIMER_CMD_START;
}

void ADC0_IRQHandler()
{
    ADC0->IFC=ADC_IFC_SINGLE;
    //Unchecked writes, notchecking flags
    unsigned int read=ADC0->SINGLEDATA;
    USART0->TXDATA=read >> 8;
    USART0->TXDATA=read & 0xff;
}
//HIPEAC+EWSN demo stuff -- end

#endif //CURRENTSENSOR_H