Quick start guide for TSL2591 Light sensor Driver

This is the quick start guide for the Driver for TSL2591 Light sensor, with step-by-step instructions on how to configure and use the driver in a selection of use cases.

The use cases contain several code fragments. The code fragments in the steps for setup can be copied into a custom initialization function, while the steps for usage can be copied into, e.g., the main application function.

TSL2591 Driver use cases

• Initialise the driver
• How to perform a new measuring with the sensor

Initialise the driver

The following must be added to the project:

#include <tsl2591.h>

Call back function

The driver needs a call back function to that it will call to tell the result of a function call.

An simple example of a call back function can be seen here:

void tsl2591Callback(tsl2591_returnCode_t rc)
{
       uint16_t _tmp;
       float _lux;
       switch (rc)
       {
       case TSL2591_DATA_READY:
              if ( TSL2591_OK == (rc = tsl2591_getFullSpectrumRaw(&_tmp)) )
              {
                     printf("\nFull Raw:%04X\n", _tmp);
              }
              else if( TSL2591_OVERFLOW == rc )
              {
                     printf("\nFull spectrum overflow - change gain and integration time\n");
              }
 
              if ( TSL2591_OK == (rc = tsl259_getVisibleRaw(&_tmp)) )
              {
                     printf("Visible Raw:%04X\n", _tmp);
              }
              else if( TSL2591_OVERFLOW == rc )
              {
                     printf("Visible overflow - change gain and integration time\n");
              }
 
              if ( TSL2591_OK == (rc = tsl2591_getInfraredRaw(&_tmp)) )
              {
                     printf("Infrared Raw:%04X\n", _tmp);
              }
              else if( TSL2591_OVERFLOW == rc )
              {
                     printf("Infrared overflow - change gain and integration time\n");
              }
 
              if ( TSL2591_OK == (rc = tsl2591_getLux(&_lux)) )
              {
                     printf("Lux: %5.4f\n", _lux);
              }
              else if( TSL2591_OVERFLOW == rc )
              {
                     printf("Lux overflow - change gain and integration time\n");
              }
       break;
 
       case TSL2591_OK:
       // Last command performed successful
       break;
 
       case TSL2591_DEV_ID_READY:
       // Dev ID now fetched
       break;
 
       default:
       break;
       }
}

Add to application initialization:

Initialise the driver by given it a function pointer to your call back function (in this example: tsl2591Callback):

if ( TSL2591_OK == tsl2591_initialise(tsl2591Callback) )
{
       // Driver initilised OK
       // Always check what tsl2591_initialise() returns
}

How to perform a new measuring with the sensor

In this use case, the steps to perform a measuring is shown.

Note

The driver must be initialised (see Initialise the driver) before a measuring is possible.

The sensor must be powered up before it can be used. This is done with the following command:

if ( TSL2591_OK == tsl2591_enable() )
{
       // The power up command is now send to the sensor - it can be powered down with a call to tsl2591_disable()
}

Note

The sensor is not powered up before the driver calls the call back function with TSL2591_OK. It is only necessary to power up the sensor once - or if it has been powered down with a call to tsl2591_disable()

Start the measuring

The following must be added to the application code:

if ( TSL2591_OK != tsl2591_fetchData() )
{
       // Something went wrong
       // Investigate the return code further
}
else
{
       The light data will be ready after the driver calls the call back function with TSL2591_DATA_READY.
}