extern const is31_led g_is31_leds[DRIVER_LED_TOTAL];
-void IS31FL3731_init( uint8_t addr );
-void IS31FL3731_write_register( uint8_t addr, uint8_t reg, uint8_t data );
-void IS31FL3731_write_pwm_buffer( uint8_t addr, uint8_t *pwm_buffer );
+uint8_t IS31FL3731_init( uint8_t addr );
+uint8_t IS31FL3731_write_register( uint8_t addr, uint8_t reg, uint8_t data );
+uint8_t IS31FL3731_write_pwm_buffer( uint8_t addr, uint8_t *pwm_buffer );
void IS31FL3731_set_color( int index, uint8_t red, uint8_t green, uint8_t blue );
void IS31FL3731_set_color_all( uint8_t red, uint8_t green, uint8_t blue );
// (eg. from a timer interrupt).
// Call this while idle (in between matrix scans).
// If the buffer is dirty, it will update the driver with the buffer.
-void IS31FL3731_update_pwm_buffers( uint8_t addr1, uint8_t addr2 );
-void IS31FL3731_update_led_control_registers( uint8_t addr1, uint8_t addr2 );
+uint8_t IS31FL3731_update_pwm_buffers( uint8_t addr1, uint8_t addr2 );
+uint8_t IS31FL3731_update_led_control_registers( uint8_t addr1, uint8_t addr2 );
#define C1_1 0x24
#define C1_2 0x25