OSX C++ version of the Python script I normally use under Linux to gather temperature from Go!Temp temperature sensors. Thanks for making everything about USB HID difficult, Apple.

gotemp-read-osx.cpp

/*
 * Ugh. This code is pretty bad. But, it's the only basis I've been able
 * to use successfully on OSX, since Apple stupidly auto-claims every single
 * HID device on the system, making it unwritable via libusb, etc. unless you
 * write an actual driver for it.
 *
 * So this will have to do.
 */
/*********************************************************************************

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      names of its contributors may be used to endorse or promote products
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 **********************************************************************************/


#include <stdio.h>
#include <string.h>
#include <memory.h>
#include <sys/time.h>
#include <Carbon/Carbon.h>
#include "GoIO_DLL_interface.h"

#define MAX_NUM_MEASUREMENTS 100


bool GetAvailableDeviceName(char *deviceName, gtype_int32 nameLength,
                            gtype_int32 *pVendorId, gtype_int32 *pProductId);
static void OSSleep(unsigned long msToSleep);


int main(int argc, char* argv[])
{
    char deviceName[GOIO_MAX_SIZE_DEVICE_NAME];
    gtype_int32 usbVendorId;
    gtype_int32 usbProductId;

    gtype_int32 rawMeasurements[MAX_NUM_MEASUREMENTS];
    gtype_real64 volts[MAX_NUM_MEASUREMENTS];
    gtype_real64 calbMeasurements[MAX_NUM_MEASUREMENTS];
    gtype_int32 numMeasurements, i;
    gtype_real64 avgReadingC;
    gtype_real64 avgReadingF;
    gtype_real64 ts;

    GoIO_Init();

    bool bFoundDevice = GetAvailableDeviceName(deviceName, GOIO_MAX_SIZE_DEVICE_NAME,
                                               &usbVendorId, &usbProductId);
    if (!bFoundDevice) {
        printf("No Go devices found.\n");
        GoIO_Uninit();
        return 1;
    }


    GOIO_SENSOR_HANDLE hDevice = GoIO_Sensor_Open(deviceName, usbVendorId, usbProductId, 0);
    if (hDevice == NULL) {
        return 1;
    }
    
    GoIO_Sensor_SetMeasurementPeriod(hDevice, 0.040, SKIP_TIMEOUT_MS_DEFAULT); //40ms measurement period
    GoIO_Sensor_SendCmdAndGetResponse(hDevice, SKIP_CMD_ID_START_MEASUREMENTS,
                                      NULL, 0, NULL, NULL, SKIP_TIMEOUT_MS_DEFAULT);

    do {
        OSSleep(250);
        numMeasurements = GoIO_Sensor_ReadRawMeasurements(hDevice, rawMeasurements,
                                                          MAX_NUM_MEASUREMENTS);
    } while (numMeasurements < 1);

    struct timeval tv;
    gettimeofday(&tv, NULL);
    ts = tv.tv_sec + ((gtype_real64)tv.tv_usec / 1000000.0);


    avgReadingC = 0.0;
    for (i = 0; i < numMeasurements; i++) {
        volts[i] = GoIO_Sensor_ConvertToVoltage(hDevice, rawMeasurements[i]);
        calbMeasurements[i] = GoIO_Sensor_CalibrateData(hDevice, volts[i]);
        avgReadingC += calbMeasurements[i];
    }

    if (numMeasurements > 1) {
        avgReadingC = avgReadingC / numMeasurements;
    }

    avgReadingF = (9.0 / 5.0) * avgReadingC + 32.0;
    printf("%f|%f|%f\n", ts, avgReadingC, avgReadingF);

    GoIO_Sensor_Close(hDevice);
    GoIO_Uninit();
    return 0;
}


bool GetAvailableDeviceName(char *deviceName, gtype_int32 nameLength,
                            gtype_int32 *pVendorId, gtype_int32 *pProductId)
{
    bool bFoundDevice = false;
    int numDevices = GoIO_UpdateListOfAvailableDevices(VERNIER_DEFAULT_VENDOR_ID,
                                                      USB_DIRECT_TEMP_DEFAULT_PRODUCT_ID);
    deviceName[0] = 0;

    if (numDevices > 0)
    {
        GoIO_GetNthAvailableDeviceName(deviceName, nameLength,
                                       VERNIER_DEFAULT_VENDOR_ID,
                                       USB_DIRECT_TEMP_DEFAULT_PRODUCT_ID,
                                       0);
        *pVendorId = VERNIER_DEFAULT_VENDOR_ID;
        *pProductId = USB_DIRECT_TEMP_DEFAULT_PRODUCT_ID;
        bFoundDevice = true;
    }

    return bFoundDevice;
}


void OSSleep(
    unsigned long msToSleep)//milliseconds
{
    /*
     * Vernier apparently hasn't built this SDK sample in a while; the calls
     * below have been deprecated since 10.8 came out. XCode will very nicely
     * inform you during build...
     */
    AbsoluteTime absTime = ::AddDurationToAbsolute(msToSleep * durationMillisecond, ::UpTime());
    ::MPDelayUntil(&absTime);
}