I am working on software in which I need to access the temperature sensors in the CPU and get control over them.
I don't know much hardware interfacing; I just know how to interface with the mouse. I have googled a lot about it but failed to find any relevant information or piece of code.
I really need to add this in my software. Please guide me how to have the control over the sensors using C or C++ or ASM.
Without a specific kernel driver, it's difficult to query the temperature, other than through WMI. Here is a piece of C code that does it, based on WMI's MSAcpi_ThermalZoneTemperature class:
HRESULT GetCpuTemperature(LPLONG pTemperature)
{
if (pTemperature == NULL)
return E_INVALIDARG;
*pTemperature = -1;
HRESULT ci = CoInitialize(NULL); // needs comdef.h
HRESULT hr = CoInitializeSecurity(NULL, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL);
if (SUCCEEDED(hr))
{
IWbemLocator *pLocator; // needs Wbemidl.h & Wbemuuid.lib
hr = CoCreateInstance(CLSID_WbemAdministrativeLocator, NULL, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID*)&pLocator);
if (SUCCEEDED(hr))
{
IWbemServices *pServices;
BSTR ns = SysAllocString(L"root\\WMI");
hr = pLocator->ConnectServer(ns, NULL, NULL, NULL, 0, NULL, NULL, &pServices);
pLocator->Release();
SysFreeString(ns);
if (SUCCEEDED(hr))
{
BSTR query = SysAllocString(L"SELECT * FROM MSAcpi_ThermalZoneTemperature");
BSTR wql = SysAllocString(L"WQL");
IEnumWbemClassObject *pEnum;
hr = pServices->ExecQuery(wql, query, WBEM_FLAG_RETURN_IMMEDIATELY | WBEM_FLAG_FORWARD_ONLY, NULL, &pEnum);
SysFreeString(wql);
SysFreeString(query);
pServices->Release();
if (SUCCEEDED(hr))
{
IWbemClassObject *pObject;
ULONG returned;
hr = pEnum->Next(WBEM_INFINITE, 1, &pObject, &returned);
pEnum->Release();
if (SUCCEEDED(hr))
{
BSTR temp = SysAllocString(L"CurrentTemperature");
VARIANT v;
VariantInit(&v);
hr = pObject->Get(temp, 0, &v, NULL, NULL);
pObject->Release();
SysFreeString(temp);
if (SUCCEEDED(hr))
{
*pTemperature = V_I4(&v);
}
VariantClear(&v);
}
}
}
if (ci == S_OK)
{
CoUninitialize();
}
}
}
return hr;
}
and some test code:
HRESULT GetCpuTemperature(LPLONG pTemperature);
int _tmain(int argc, _TCHAR* argv[])
{
LONG temp;
HRESULT hr = GetCpuTemperature(&temp);
printf("hr=0x%08x temp=%i\n", hr, temp);
}