This is the DW1000 driver and our self developed distance measurement application based on it. We do this as a semester thesis at ETH Zürich under the Automatic Control Laboratory in the Department of electrical engineering.

Dependencies:   mbed

DW1000/DW1000.cpp

Committer:
manumaet
Date:
2014-11-18
Revision:
4:6240b9c7a033
Parent:
0:f50e671ffff7
Child:
7:e634eeafc4d2

File content as of revision 4:6240b9c7a033:

#include "DW1000.h"

DW1000::DW1000(PinName MOSI, PinName MISO, PinName SCLK, PinName CS) : spi(MOSI, MISO, SCLK), cs(CS)
{
    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)
}

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);
}

void DW1000::sendFrame(char* message, int length) {
    writeRegister(DW1000_TX_BUFFER, 0, (uint8_t*)message, length);  // fill buffer
    
    uint16_t framelength = length+2;                                // put length of frame including 2 CRC Bytes
    writeRegister(DW1000_TX_FCTRL, 0, (uint8_t*)&framelength, 1);
    
    uint8_t txstart = 0x02;                                         // trigger sending process
    writeRegister(DW1000_SYS_CTRL, 0, &txstart, 1);
}

void DW1000::resetRX() {
    uint8_t resetrx = 0xE0;     //set rx reset
    writeRegister(DW1000_PMSC, 3, &resetrx, 1);
    resetrx = 0xf0;             //clear RX reset
    writeRegister(DW1000_PMSC, 3, &resetrx, 1);
}

float DW1000::getVoltage() {
    uint8_t buffer[7] = {0x80, 0x0A, 0x0F, 0x01, 0x00}; // algorithm form DW1000 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;
}


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

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

void DW1000::setupTransaction(uint8_t reg, uint16_t subaddress, bool write)
{
    reg |=  (write * DW1000_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 > 127) {                                                 // sub address too long, we need to set flag and send third header byte
            spi.write((uint8_t)(subaddress & 0x7F) | DW1000_2_SUBADDRESS_FLAG);
            spi.write((uint8_t)(subaddress >> 7));
        } else {
            spi.write((uint8_t)subaddress);
        }
    } else {
        spi.write(reg);
    }
}

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