apa102.cpp

00001 #include "apa102.h"
00002 #include "mbed.h"
00003 
00004 #define DO_N(N, F) for( int repetier = 0; repetier < N; repetier++) { F; }
00005 
00006 //------------------------------------------------------------------------------------------------------------
00007 apa102::apa102(PinName CKI, PinName SDI, int STRIP_LENGTH, int reset_delay)
00008 : _CKI(CKI), _SDI(SDI), _STRIP_LENGTH(STRIP_LENGTH), _reset_delay(reset_delay) {
00009     
00010     _level=100;
00011     this->clear();
00012     wait_us(_reset_delay);
00013 }
00014 //------------------------------------------------------------------------------------------------------------
00015 void apa102::post(int *strip_colors) {
00016     this->preamble();
00017 
00018     int scaled_level = 0xE0 | (_level * 31 / 100);
00019     
00020     for(int LED_number = 0 ; LED_number < _STRIP_LENGTH ; LED_number++) {
00021         this->write_word(scaled_level, 8);
00022         this->write_word(strip_colors[LED_number], 24);
00023     }
00024     
00025     this->afterword();
00026     wait_us(_reset_delay); //Wait for 1ms to go into reset
00027 }
00028 //------------------------------------------------------------------------------------------------------------
00029 void apa102::clear(void) {
00030     this->preamble();
00031     DO_N(_STRIP_LENGTH, this->write_word(0xE0000000, 32));
00032     this->afterword();
00033 }
00034 //------------------------------------------------------------------------------------------------------------
00035 int apa102::level(int level)
00036 {
00037 if((level <= 100) && level)
00038   {
00039   _level = level;
00040   return _level;
00041   }
00042 return 0;
00043 }
00044 
00045 //------------------------------------------------------------------------------------------------------------
00046 int apa102::delay(uint32_t reset_delay)
00047 {
00048 if(reset_delay <= 0xffffffff)_reset_delay = reset_delay;
00049 return _reset_delay;
00050 }
00051 //------------------------------------------------------------------------------------------------------------
00052 inline void apa102::write_hi() {
00053     this->write_bit(1);
00054 }
00055 inline void apa102::write_lo() {
00056     this->write_bit(0);
00057 }
00058 inline void apa102::write_bit(bool bit) {
00059     _CKI = 0;
00060     _SDI = bit;
00061     _CKI = 1;
00062 }
00063 inline void apa102::write_word(uint32_t word, int bits) {
00064     for(char color_bit = bits - 1 ; color_bit != 255 ; color_bit--) {
00065         this->write_bit(
00066             (word & (1 << color_bit)) ? 1 : 0
00067         );
00068     }
00069 }
00070 inline void apa102::write_done() {
00071     _CKI = 0;
00072 }
00073 inline void apa102::preamble() {
00074     DO_N(32, this->write_lo());
00075 }
00076 inline void apa102::afterword() {
00077     DO_N(32, this->write_hi());
00078     this->write_done();
00079 }
00080 //---------EOF---------------EOF------------------------------------------------------------------------------