Add elphel_num_sensors function

src/ext/elphel/elphel_php.c

@@ -237,6 +237,7 @@ static zend_function_entry elphel_functions[] = {
         PHP_FE(elphel_histogram_get_raw, NULL)
         PHP_FE(elphel_histogram_get, NULL)
         PHP_FE(elphel_get_state, NULL)
+        PHP_FE(elphel_num_sensors, NULL)
 
         PHP_FE(elphel_compressor_reset, NULL)
         PHP_FE(elphel_compressor_run, NULL)
@@ -562,6 +563,13 @@ PHP_FUNCTION(elphel_test)
     RETURN_LONG(result);
 } 
 
+/** Return the number of sensor ports */
+PHP_FUNCTION(elphel_num_sensors)
+{
+	long result = SENSOR_PORTS;
+    RETURN_LONG(result);
+}
+
 
 ///NOTE: Just for compatibility with older code
 //!Get sensor state, usually 7- sensor is running,  compressor is stopped, 8 - compressor is runing

src/ext/elphel/elphel_php.h

@@ -93,6 +93,7 @@ PHP_FUNCTION(elphel_histogram_get_raw);
 PHP_FUNCTION(elphel_histogram_get);
 
 PHP_FUNCTION(elphel_get_state); /// compatibility with old code
+PHP_FUNCTION(elphel_num_sensors);
 
 PHP_FUNCTION(elphel_compressor_reset); /// these elphel_compressor_*() functions are for compatibility. Reset will now just stop, not actually reset
 PHP_FUNCTION(elphel_compressor_run);