Grupo Fiuba / tlc5940

This library creates the interface to operate the TLC5940. This device manages 16 PWM outputs.

tlc5940.cpp@0:64ea4d75027c, 2010-11-27 (annotated)

Committer:
Fiuba
Date:
Sat Nov 27 00:28:33 2010 +0000
Revision:
0:64ea4d75027c
Child:
1:e8c8347fa919
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Fiuba 0:64ea4d75027c 1 #include "tlc5940.h"
Fiuba 0:64ea4d75027c 2 #include "mbed.h"
Fiuba 0:64ea4d75027c 3
Fiuba 0:64ea4d75027c 4 /** Create a tlc5940 interface object connected to some specifics pins
Fiuba 0:64ea4d75027c 5 *
Fiuba 0:64ea4d75027c 6 * @param DC_data[] Dot Correction values for initialization
Fiuba 0:64ea4d75027c 7 */
Fiuba 0:64ea4d75027c 8 tlc5940::tlc5940 (int DC_data[]) : VPROG(p21), SIN(p22), SCLK(p23), XLAT(p24), BLANK(p25), DCPROG(p27), GSCLK(p26), SOUT(p28), XERR(p29) {
Fiuba 0:64ea4d75027c 9 first_cycle_flag = false;
Fiuba 0:64ea4d75027c 10
Fiuba 0:64ea4d75027c 11 // Pins in startup state
Fiuba 0:64ea4d75027c 12 GSCLK = 0;
Fiuba 0:64ea4d75027c 13 SCLK = 0;
Fiuba 0:64ea4d75027c 14 VPROG = 1;
Fiuba 0:64ea4d75027c 15 XLAT = 0;
Fiuba 0:64ea4d75027c 16 BLANK = 1;
Fiuba 0:64ea4d75027c 17 DCPROG = 0;
Fiuba 0:64ea4d75027c 18 wait(0.01);
Fiuba 0:64ea4d75027c 19
Fiuba 0:64ea4d75027c 20 // DC input cycle starts
Fiuba 0:64ea4d75027c 21 DCPROG = 1;
Fiuba 0:64ea4d75027c 22 VPROG = 1;
Fiuba 0:64ea4d75027c 23
Fiuba 0:64ea4d75027c 24 for (int counter=0; counter < (2*96); counter++) {
Fiuba 0:64ea4d75027c 25 SIN = DC_data[counter];
Fiuba 0:64ea4d75027c 26 SCLK = 1;
Fiuba 0:64ea4d75027c 27 wait_us(5);
Fiuba 0:64ea4d75027c 28 SCLK = 0;
Fiuba 0:64ea4d75027c 29 wait_us(5);
Fiuba 0:64ea4d75027c 30 }
Fiuba 0:64ea4d75027c 31 XLAT = 1;
Fiuba 0:64ea4d75027c 32 wait_us(5);
Fiuba 0:64ea4d75027c 33 XLAT = 0;
Fiuba 0:64ea4d75027c 34 wait_us(5);
Fiuba 0:64ea4d75027c 35 DCPROG = 0;
Fiuba 0:64ea4d75027c 36 // DC input cycle ends
Fiuba 0:64ea4d75027c 37 }
Fiuba 0:64ea4d75027c 38
Fiuba 0:64ea4d75027c 39 /** Send the specified set of grayscale values
Fiuba 0:64ea4d75027c 40 *
Fiuba 0:64ea4d75027c 41 * @param data[] Array of 12-bit Grayscale values for transmission
Fiuba 0:64ea4d75027c 42 */
Fiuba 0:64ea4d75027c 43 void tlc5940::send_data (int data[]) {
Fiuba 0:64ea4d75027c 44 // Grayscale data input + Grayscale PWM
Fiuba 0:64ea4d75027c 45 data_counter = 0;
Fiuba 0:64ea4d75027c 46 GSCLK_counter = 0;
Fiuba 0:64ea4d75027c 47
Fiuba 0:64ea4d75027c 48 if (VPROG == 1) {
Fiuba 0:64ea4d75027c 49 VPROG = 0;
Fiuba 0:64ea4d75027c 50 first_cycle_flag = true;
Fiuba 0:64ea4d75027c 51 }
Fiuba 0:64ea4d75027c 52
Fiuba 0:64ea4d75027c 53 // Send the new data
Fiuba 0:64ea4d75027c 54 BLANK = 0;
Fiuba 0:64ea4d75027c 55 for (GSCLK_counter = 0; GSCLK_counter <= 4095; GSCLK_counter++) {
Fiuba 0:64ea4d75027c 56 if (data_counter < 2*192) {
Fiuba 0:64ea4d75027c 57 // Every new led consists of 12 bits
Fiuba 0:64ea4d75027c 58 aux_ind = data_counter % 12;
Fiuba 0:64ea4d75027c 59 if ( aux_ind == 0 ) aux_value = data[data_counter/12];
Fiuba 0:64ea4d75027c 60 // Send the last bit
Fiuba 0:64ea4d75027c 61 SIN = (aux_value >> aux_ind) & 0x01;
Fiuba 0:64ea4d75027c 62
Fiuba 0:64ea4d75027c 63 SCLK = 1;
Fiuba 0:64ea4d75027c 64 GSCLK = 1;
Fiuba 0:64ea4d75027c 65 SCLK = 0;
Fiuba 0:64ea4d75027c 66 GSCLK = 0;
Fiuba 0:64ea4d75027c 67
Fiuba 0:64ea4d75027c 68 data_counter++;
Fiuba 0:64ea4d75027c 69 } else {
Fiuba 0:64ea4d75027c 70 GSCLK = 1;
Fiuba 0:64ea4d75027c 71 GSCLK = 0;
Fiuba 0:64ea4d75027c 72 }
Fiuba 0:64ea4d75027c 73 }
Fiuba 0:64ea4d75027c 74 BLANK = 1;
Fiuba 0:64ea4d75027c 75
Fiuba 0:64ea4d75027c 76 XLAT = 1;
Fiuba 0:64ea4d75027c 77 XLAT = 0;
Fiuba 0:64ea4d75027c 78
Fiuba 0:64ea4d75027c 79 if (first_cycle_flag) {
Fiuba 0:64ea4d75027c 80 SCLK = 1;
Fiuba 0:64ea4d75027c 81 SCLK = 0;
Fiuba 0:64ea4d75027c 82 first_cycle_flag = false;
Fiuba 0:64ea4d75027c 83 }
Fiuba 0:64ea4d75027c 84 }