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Hello world code for PCA9955A class library. The PCA9955A is a 16-channel Fm+ I2C-bus 57mA/20V constant current LED driver. This program shows its basic operation of PWM and current settings.
Please refer to the component page for details
High-level API is available
A high-level API that can be used as the "PwmOut" of bed-SDK is available.
This API enables to make instances of each LED output pins and control PWM duty cycle by assignment.
Output current also controllable by API function.
For detail information, refer API document of LedPwmOutCC Class
class which is included in PCA995xA class library.
#include "mbed.h" #include "PCA9956A.h" PCA9956A led_cntlr( p28, p27, 0xC4 ); // SDA, SCL, Slave_address(option) LedPwmOutCC led( led_cntlr, L0 ); int main() { while( 1 ) { for( float p = 0.0f; p < 1.0f; p += 0.1f ) { led = p; wait( 0.1 ); } } }
Diff: main.cpp
- Revision:
- 6:9abd0b582c2c
- Parent:
- 5:e2ad761c8570
diff -r e2ad761c8570 -r 9abd0b582c2c main.cpp --- a/main.cpp Thu Jun 16 23:39:18 2022 +0000 +++ b/main.cpp Tue Jun 21 09:13:41 2022 +0000 @@ -1,19 +1,21 @@ #include "mbed.h" #include "PCA9955A.h" +// making an instance of PCA9955A (PCA9955A is cpmpatible to PCA9955B) PCA9955A led_cntlr( p28, p27, 0x02 ); // SDA, SCL, Slave_address(option) +// LED output instances in array LedPwmOutCC leds[] = { - LedPwmOutCC ( led_cntlr, L0 ), // Instance for LED0 pin - LedPwmOutCC ( led_cntlr, L1 ), // Instance for LED1 pin - LedPwmOutCC ( led_cntlr, L2 ), // Instance for LED2 pin - LedPwmOutCC ( led_cntlr, L3 ), // Instance for LED3 pin - LedPwmOutCC ( led_cntlr, L4 ), // Instance for LED4 pin - LedPwmOutCC ( led_cntlr, L5 ), // Instance for LED5 pin - LedPwmOutCC ( led_cntlr, L6 ), // Instance for LED6 pin - LedPwmOutCC ( led_cntlr, L7 ), // Instance for LED7 pin - LedPwmOutCC ( led_cntlr, L8 ), // Instance for LED8 pin - LedPwmOutCC ( led_cntlr, L9 ), // Instance for LED9 pin + LedPwmOutCC ( led_cntlr, L0 ), // Instance for LED0 pin + LedPwmOutCC ( led_cntlr, L1 ), // Instance for LED1 pin + LedPwmOutCC ( led_cntlr, L2 ), // Instance for LED2 pin + LedPwmOutCC ( led_cntlr, L3 ), // Instance for LED3 pin + LedPwmOutCC ( led_cntlr, L4 ), // Instance for LED4 pin + LedPwmOutCC ( led_cntlr, L5 ), // Instance for LED5 pin + LedPwmOutCC ( led_cntlr, L6 ), // Instance for LED6 pin + LedPwmOutCC ( led_cntlr, L7 ), // Instance for LED7 pin + LedPwmOutCC ( led_cntlr, L8 ), // Instance for LED8 pin + LedPwmOutCC ( led_cntlr, L9 ), // Instance for LED9 pin LedPwmOutCC ( led_cntlr, L10 ), // Instance for LED10 pin LedPwmOutCC ( led_cntlr, L11 ), // Instance for LED11 pin LedPwmOutCC ( led_cntlr, L12 ), // Instance for LED12 pin @@ -24,16 +26,15 @@ int main() { - for ( int i = 0; i < 16; i++ ) - leds[ i ].current( 0.5 ); // LED pin current output setting to 50% + for ( int i = 0; i < 16; i++ ) + leds[ i ].current( 0.5 ); // LED output current set to 50% while(1) { - for ( int i = 0; i < 16; i++ ) - { + for ( int i = 0; i < 16; i++ ) { for ( float p = 1.0; p >= 0.0; p -= 0.01 ) { - leds[ i ] = p; // Set LED0 output PWM dutycycle as 'p' + leds[ i ] = p; // set 'p' value into LED output instance wait( 0.01 ); } - } + } } }