File content as of revision 19:e94bc88c1eb0:

#include "DW1000.h"

DW1000::DW1000(PinName MOSI, PinName MISO, PinName SCLK, PinName CS, PinName IRQ) : spi(MOSI, MISO, SCLK), cs(CS), irq(IRQ) {
    receiving = 0;                      // state in the beginning is not listening for frames
    
    deselect();                         // Chip must be deselected first
    spi.format(8,0);                    // Setup the spi for standard 8 bit data and SPI-Mode 0 (GPIO5, GPIO6 open circuit or ground on DW1000)
    spi.frequency(1000000);             // with a 1MHz clock rate (worked up to 49MHz in our Test)
    
    resetAll();                         // we can do a soft reset if we want to (only needed for debugging)
    loadLDE();                          // important everytime DW1000 initialises/awakes otherwise the LDE algorithm must be turned of or there's receiving malfunction see User Manual LDELOAD on p22 & p158
    
    // Configuration TODO: make method for that
    writeRegister8(DW1000_SYS_CFG, 3, 0x20); // enable auto reenabling receiver after error
    writeRegister8(DW1000_SYS_CFG, 2, 0x03); // enable 1024 byte frames TODO: doesn't work!!
    
    irq.rise(this, &DW1000::ISR);       // attach Interrupt handler to rising edge
}

uint32_t DW1000::getDeviceID() {
    uint32_t result;
    readRegister(DW1000_DEV_ID, 0, (uint8_t*)&result, 4);
    return result;
}

uint64_t DW1000::getEUI() {
    uint64_t result;
    readRegister(DW1000_EUI, 0, (uint8_t*)&result, 8);
    return result;
}

void DW1000::setEUI(uint64_t EUI) {
    writeRegister(DW1000_EUI, 0, (uint8_t*)&EUI, 8);
}

float DW1000::getVoltage() {
    uint8_t buffer[7] = {0x80, 0x0A, 0x0F, 0x01, 0x00};             // algorithm form User Manual p57
    writeRegister(DW1000_RF_CONF, 0x11, buffer, 2);
    writeRegister(DW1000_RF_CONF, 0x12, &buffer[2], 1);
    writeRegister(DW1000_TX_CAL, 0x00, &buffer[3], 1);
    writeRegister(DW1000_TX_CAL, 0x00, &buffer[4], 1);
    readRegister(DW1000_TX_CAL, 0x03, &buffer[5], 2);               // get the 8-Bit readings for Voltage and Temperature
    float Voltage = buffer[5] * 0.0057 + 2.3;
    float Temperature = buffer[6] * 1.13 - 113.0;                   // TODO: getTemperature was always ~35 degree with better formula/calibration see instance_common.c row 391
    return Voltage;
}

uint64_t DW1000::getStatus() {
    return readRegister40(DW1000_SYS_STATUS, 0);
}

void DW1000::sendString(char* message) {
    sendFrame((uint8_t*)message, strlen(message)+1);
}

char* DW1000::receiveString() {
    uint16_t framelength = 0;                                       // get framelength
    readRegister(DW1000_RX_FINFO, 0, (uint8_t*)&framelength, 2);
    framelength = (framelength & 0x03FF) - 2;                       // take only the right bits and subtract the 2 CRC Bytes
    char* receive = new char[framelength];                          // get data from buffer
    readRegister(DW1000_RX_BUFFER, 0, (uint8_t*)receive, framelength);
    return receive;
}

void DW1000::sendFrame(uint8_t* message, uint16_t length) {
    if (length >= 1021) length = 1021;
    writeRegister(DW1000_TX_BUFFER, 0, message, length);            // fill buffer
    
    uint8_t backup = readRegister8(DW1000_TX_FCTRL, 1);             // put length of frame including 2 CRC Bytes
    length += 2;
    length = ((backup & 0xFC) << 8) | (length & 0x03FF);
    writeRegister(DW1000_TX_FCTRL, 0, (uint8_t*)&length, 2);
    
    if (receiving) stopTRX();                                       // stop receiving if we are in this state
    writeRegister8(DW1000_SYS_CTRL, 0, 0x02);                       // trigger sending process by setting the TXSTRT bit
    //if (receiving) startRX();                                       // enable receiver again if we need to preserve state          TODO: safe to do this directly ??? only after sending ended
}

void DW1000::startRX() {
    receiving = true;
    writeRegister8(DW1000_SYS_CTRL, 0x01, 0x01);                       // start listening for preamble by setting the RXENAB bit
}

void DW1000::stopRX() {
    receiving = false;
    stopTRX();
}

void DW1000::ISR() {
    uint64_t status = getStatus();
    if (status & 0x4000) {
        callbackRX(getFramelength());
    }
    if (status & 0x80) {
        if (receiving) startRX();                                // enable receiver again if we need to preserve state          TODO: have to do it here??
        callbackTX();
    }
}

uint16_t DW1000::getFramelength() {
    uint16_t framelength = readRegister16(DW1000_RX_FINFO, 0);                                       // get framelength TODO: get this from isr
    framelength &= 0x03FF;
    framelength -= 2;
    return framelength;
}

void DW1000::loadLDE() {                                            // initialise LDE algorithm LDELOAD User Manual p22
    writeRegister16(DW1000_PMSC, 0, 0x0301);                        // set clock to XTAL so OTP is reliable
    writeRegister16(DW1000_OTP_IF, 0x06, 0x8000);                        // set LDELOAD bit in OTP
    wait_us(150);
    writeRegister16(DW1000_PMSC, 0, 0x0200);                        // recover to PLL clock
}

void DW1000::stopTRX() {
    writeRegister8(DW1000_SYS_CTRL, 0, 0x40);                       // disable tranceiver go back to idle mode
}

void DW1000::resetRX() {    
    writeRegister8(DW1000_PMSC, 3, 0xE0);   // set RX reset
    writeRegister8(DW1000_PMSC, 3, 0xF0);   // clear RX reset
}

void DW1000::resetAll() {
    writeRegister8(DW1000_PMSC, 0, 0x01);   // set clock to XTAL
    writeRegister8(DW1000_PMSC, 3, 0x00);   // set All reset
    wait_us(10);                            // wait for PLL to lock
    writeRegister8(DW1000_PMSC, 3, 0xF0);   // clear All reset
}

// SPI Interface ------------------------------------------------------------------------------------
uint8_t DW1000::readRegister8(uint8_t reg, uint16_t subaddress) {
    uint8_t result;
    readRegister(reg, subaddress, &result, 1);
    return result;
}

uint16_t DW1000::readRegister16(uint8_t reg, uint16_t subaddress) {
    uint16_t result;
    readRegister(reg, subaddress, (uint8_t*)&result, 2);
    return result;
}

uint64_t DW1000::readRegister40(uint8_t reg, uint16_t subaddress) {
    uint64_t result;
    readRegister(reg, subaddress, (uint8_t*)&result, 5);
    result &= 0xFFFFFFFFFF;                                 // only 40-Bit
    return result;
}

void DW1000::writeRegister8(uint8_t reg, uint16_t subaddress, uint8_t buffer) {
    writeRegister(reg, subaddress, &buffer, 1);
}

void DW1000::writeRegister16(uint8_t reg, uint16_t subaddress, uint16_t buffer) {
    writeRegister(reg, subaddress, (uint8_t*)&buffer, 2);
}

void DW1000::readRegister(uint8_t reg, uint16_t subaddress, uint8_t *buffer, int length) {
    setupTransaction(reg, subaddress, false);
    for(int i=0; i<length; i++)                             // get data
        buffer[i] = spi.write(0x00);
    deselect();
}

void DW1000::writeRegister(uint8_t reg, uint16_t subaddress, uint8_t *buffer, int length) {
    setupTransaction(reg, subaddress, true);
    for(int i=0; i<length; i++)                             // put data
        spi.write(buffer[i]);
    deselect();
}

void DW1000::setupTransaction(uint8_t reg, uint16_t subaddress, bool write) {
    reg |=  (write * DW1000_WRITE_FLAG);                                        // set read/write flag
    select();
    if (subaddress > 0) {                                                       // there's a subadress, we need to set flag and send second header byte
        spi.write(reg | DW1000_SUBADDRESS_FLAG);
        if (subaddress > 0x7F) {                                                // sub address too long, we need to set flag and send third header byte
            spi.write((uint8_t)(subaddress & 0x7F) | DW1000_2_SUBADDRESS_FLAG); // and 
            spi.write((uint8_t)(subaddress >> 7));
        } else {
            spi.write((uint8_t)subaddress);
        }
    } else {
        spi.write(reg);                                                         // say which register address we want to access
    }
}

void DW1000::select() { cs = 0; }   // set CS low to start transmission
void DW1000::deselect() { cs = 1; } // set CS high to stop transmission