Andrew Duda / TLC5940Servo

Library for using the TLC5940 as a servo controller.

Dependencies:   FastPWM

Dependents:   TLC5940ServoTest

TLC5940Servo.h@5:56daa8c0697d, 2014-10-21 (annotated)

Committer:
dudanian
Date:
Tue Oct 21 06:26:25 2014 +0000
Revision:
5:56daa8c0697d
Parent:
4:95305d4b0544
Child:
6:b001282e967b
Added mbed official docs for the Server inner class as well as support for the position(float degrees) function from the official mbed class.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
dudanian 0:9fc434ff7a03 1 #ifndef TLC5940Servo_H
dudanian 0:9fc434ff7a03 2 #define TLC5940Servo_H
dudanian 0:9fc434ff7a03 3
dudanian 0:9fc434ff7a03 4 #include "FastPWM.h"
dudanian 2:1d2251574d35 5
dudanian 0:9fc434ff7a03 6 /**
dudanian 0:9fc434ff7a03 7 * SPI speed used by the mbed to communicate with the TLC5940
dudanian 0:9fc434ff7a03 8 * The TLC5940 supports up to 30Mhz. This should be kept as high
dudanian 0:9fc434ff7a03 9 * as possible to ensure that data has time to be sent each reset cycle.
dudanian 0:9fc434ff7a03 10 */
dudanian 0:9fc434ff7a03 11 #define SPI_SPEED 30000000
dudanian 0:9fc434ff7a03 12
dudanian 0:9fc434ff7a03 13 /**
dudanian 0:9fc434ff7a03 14 * The rate at which the GSCLK pin is pulsed
dudanian 0:9fc434ff7a03 15 * This also controls how often the reset function is called
dudanian 0:9fc434ff7a03 16 * The rate at which the reset function is called can be calculated by: (1/GSCLK_SPEED) * 4096
dudanian 2:1d2251574d35 17 *
dudanian 2:1d2251574d35 18 * Since the Servo period is 20ms (50Hz), we set this clock to 50*4096 = 204,800Hz according to the equation above
dudanian 2:1d2251574d35 19 * Also, since this clock is so slow, there is almost no limit to the number of TLC5940s you can chain
dudanian 0:9fc434ff7a03 20 */
dudanian 0:9fc434ff7a03 21 #define GSCLK_SPEED 204800
dudanian 0:9fc434ff7a03 22
dudanian 0:9fc434ff7a03 23 /**
dudanian 2:1d2251574d35 24 * This class controls a TLC5940 PWM driver to control Servo motors. It supports sending grayscale PWM data calibrated for Servos,
dudanian 2:1d2251574d35 25 * but it does not support error checking or writing the EEPROM. After 4096 pulses, the private member funciton reset is called by
dudanian 2:1d2251574d35 26 * the ticker. It resets the driver by pulsing the BLANK pin. If new data has been set to be sent by the function setNewData, it
dudanian 2:1d2251574d35 27 * is sent here.
dudanian 2:1d2251574d35 28 *
dudanian 2:1d2251574d35 29 * This class is a heavily modified versoin of the TLC5940 library created by Spencer Davis. This class also uses the FastPWM
dudanian 2:1d2251574d35 30 * library by Erik Olieman to continuously pulse the GSLCK pin without CPU intervention.
dudanian 0:9fc434ff7a03 31 */
dudanian 2:1d2251574d35 32 class TLC5940Servo {
dudanian 0:9fc434ff7a03 33 public:
dudanian 2:1d2251574d35 34 /*
dudanian 2:1d2251574d35 35 * Servo inner class to abstract some of the details. Based off of the mbed official Servo class
dudanian 2:1d2251574d35 36 */
dudanian 2:1d2251574d35 37 class Servo {
dudanian 2:1d2251574d35 38 public:
dudanian 5:56daa8c0697d 39 /**
dudanian 5:56daa8c0697d 40 * Creat a servo object NOT connected to a specific PwmOut pin
dudanian 5:56daa8c0697d 41 */
dudanian 2:1d2251574d35 42 Servo();
dudanian 5:56daa8c0697d 43
dudanian 4:95305d4b0544 44 /**
dudanian 4:95305d4b0544 45 * Set the servo position, normalised to it's full range
dudanian 4:95305d4b0544 46 *
dudanian 4:95305d4b0544 47 * @param percent A normalised number 0.0-1.0 to represent the full range.
dudanian 4:95305d4b0544 48 */
dudanian 2:1d2251574d35 49 void write(float percent);
dudanian 5:56daa8c0697d 50
dudanian 5:56daa8c0697d 51 /**
dudanian 5:56daa8c0697d 52 * Read the servo motors current position
dudanian 5:56daa8c0697d 53 *
dudanian 5:56daa8c0697d 54 * @param returns A normalised number 0.0-1.0 representing the full range.
dudanian 5:56daa8c0697d 55 */
dudanian 2:1d2251574d35 56 float read();
dudanian 5:56daa8c0697d 57
dudanian 5:56daa8c0697d 58 /**
dudanian 5:56daa8c0697d 59 * Set the servo position
dudanian 5:56daa8c0697d 60 *
dudanian 5:56daa8c0697d 61 * @param degrees Servo position in degrees
dudanian 5:56daa8c0697d 62 */
dudanian 5:56daa8c0697d 63 void position(float degrees);
dudanian 5:56daa8c0697d 64
dudanian 5:56daa8c0697d 65 /**
dudanian 5:56daa8c0697d 66 * Allows calibration of the range and angles for a particular servo
dudanian 5:56daa8c0697d 67 *
dudanian 5:56daa8c0697d 68 * @param range Pulsewidth range from center (1.5ms) to maximum/minimum position in seconds
dudanian 5:56daa8c0697d 69 * @param degrees Angle from centre to maximum/minimum position in degrees
dudanian 5:56daa8c0697d 70 */
dudanian 5:56daa8c0697d 71 void calibrate(float range=0.0005, float degrees=45.0);
dudanian 5:56daa8c0697d 72
dudanian 5:56daa8c0697d 73 /**
dudanian 5:56daa8c0697d 74 * Read the servo motors current TLC5940 pw value
dudanian 5:56daa8c0697d 75 */
dudanian 2:1d2251574d35 76 int pulsewidth();
dudanian 5:56daa8c0697d 77
dudanian 5:56daa8c0697d 78 /** Shorthand for the write and read functions */
dudanian 2:1d2251574d35 79 Servo& operator= (float percent);
dudanian 5:56daa8c0697d 80 Servo& operator= (Servo& rhs);
dudanian 2:1d2251574d35 81 operator float();
dudanian 2:1d2251574d35 82 private:
dudanian 2:1d2251574d35 83 float _range;
dudanian 2:1d2251574d35 84 float _degrees;
dudanian 5:56daa8c0697d 85 float _p;
dudanian 2:1d2251574d35 86 int _pw;
dudanian 2:1d2251574d35 87 };
dudanian 5:56daa8c0697d 88
dudanian 0:9fc434ff7a03 89 /**
dudanian 2:1d2251574d35 90 * Set up the TLC5940
dudanian 2:1d2251574d35 91 *
dudanian 2:1d2251574d35 92 * @param MOSI - The MOSI pin of the SPI bus
dudanian 2:1d2251574d35 93 * @param SCLK - The SCK pin of the SPI bus
dudanian 2:1d2251574d35 94 * @param XLAT - The XLAT pin of the TLC5940(s)
dudanian 2:1d2251574d35 95 * @param BLANK - The BLANK pin of the TLC5940(s)
dudanian 2:1d2251574d35 96 * @param GSCLK - The GSCLK pin of the TLC5940(s)
dudanian 2:1d2251574d35 97 * @param number - The number of TLC5940s (optional)
dudanian 0:9fc434ff7a03 98 */
dudanian 0:9fc434ff7a03 99 TLC5940Servo(PinName MOSI, PinName SCLK, PinName XLAT, PinName BLANK,
dudanian 2:1d2251574d35 100 PinName GSCLK, const int number = 1);
dudanian 2:1d2251574d35 101
dudanian 2:1d2251574d35 102 /**
dudanian 2:1d2251574d35 103 * Destructor used to delete memory
dudanian 2:1d2251574d35 104 */
dudanian 0:9fc434ff7a03 105 ~TLC5940Servo();
dudanian 0:9fc434ff7a03 106
dudanian 2:1d2251574d35 107 /**
dudanian 2:1d2251574d35 108 * Allows calibration of the range and angles for a particular servo
dudanian 0:9fc434ff7a03 109 *
dudanian 0:9fc434ff7a03 110 * @param range Pulsewidth range from center (1.5ms) to maximum/minimum position in seconds
dudanian 0:9fc434ff7a03 111 * @param degrees Angle from centre to maximum/minimum position in degrees
dudanian 0:9fc434ff7a03 112 */
dudanian 0:9fc434ff7a03 113 void calibrate(int index, float range, float degrees);
dudanian 2:1d2251574d35 114
dudanian 2:1d2251574d35 115 /**
dudanian 2:1d2251574d35 116 * Allows calibration of the range and angles for all servos
dudanian 0:9fc434ff7a03 117 *
dudanian 0:9fc434ff7a03 118 * @param range Pulsewidth range from center (1.5ms) to maximum/minimum position in seconds
dudanian 0:9fc434ff7a03 119 * @param degrees Angle from centre to maximum/minimum position in degrees
dudanian 0:9fc434ff7a03 120 */
dudanian 2:1d2251574d35 121 void calibrate(float range, float degrees);
dudanian 2:1d2251574d35 122
dudanian 0:9fc434ff7a03 123 /**
dudanian 2:1d2251574d35 124 * Array index operator for reading and writing from servos
dudanian 2:1d2251574d35 125 *
dudanian 2:1d2251574d35 126 * @param index Index of Servo in array
dudanian 0:9fc434ff7a03 127 */
dudanian 2:1d2251574d35 128 Servo& operator[](int index);
dudanian 0:9fc434ff7a03 129
dudanian 0:9fc434ff7a03 130 private:
dudanian 0:9fc434ff7a03 131 // SPI port - only MOSI and SCK are used
dudanian 0:9fc434ff7a03 132 SPI spi;
dudanian 0:9fc434ff7a03 133
dudanian 0:9fc434ff7a03 134 // PWM output using the FastPWM library by Erik Olieman
dudanian 0:9fc434ff7a03 135 FastPWM gsclk;
dudanian 0:9fc434ff7a03 136
dudanian 0:9fc434ff7a03 137 // Digital out pins used for the TLC5940
dudanian 0:9fc434ff7a03 138 DigitalOut blank;
dudanian 0:9fc434ff7a03 139 DigitalOut xlat;
dudanian 0:9fc434ff7a03 140
dudanian 0:9fc434ff7a03 141 // Number of TLC5940s in series
dudanian 0:9fc434ff7a03 142 const int number;
dudanian 0:9fc434ff7a03 143
dudanian 0:9fc434ff7a03 144 // Call a reset function to manage sending data and GSCLK updating
dudanian 0:9fc434ff7a03 145 Ticker reset_ticker;
dudanian 0:9fc434ff7a03 146
dudanian 0:9fc434ff7a03 147 // Has new data been loaded?
dudanian 0:9fc434ff7a03 148 volatile bool newData;
dudanian 0:9fc434ff7a03 149
dudanian 0:9fc434ff7a03 150 // Do we need to send an XLAT pulse? (Was GS data clocked in last reset?)
dudanian 0:9fc434ff7a03 151 volatile bool need_xlat;
dudanian 0:9fc434ff7a03 152
dudanian 0:9fc434ff7a03 153 // Buffers to store data until it is sent
dudanian 3:3b04a122e508 154 Servo* servos;
dudanian 0:9fc434ff7a03 155
dudanian 0:9fc434ff7a03 156 // Function to reset the display and send the next chunks of data
dudanian 0:9fc434ff7a03 157 void reset();
dudanian 0:9fc434ff7a03 158 };
dudanian 0:9fc434ff7a03 159
dudanian 0:9fc434ff7a03 160 #endif