I tried to make use of the LIBSTOCK package but:
1. Found it too confusing.
2. There was a detailed but unfruitful discussion about it not working.
I'm not saying that there is/was anything wrong with the LIBSTOCK package but it did not suit my level of knowledge
partly because it was made so flexible to run on different MCUs with a big variety of compilers.
If anyone else has had this problem with LIBSTOCK - please comment so that the fellows at MikroElektronika can think abut it?
My code follows:
Code: Select all
////////////////////////////////////////////////////////////////////////////////
// Project: Thumper_Servo_01 //
// Fiile: Main.c //
// Function: Test Adafruit servo driver PCA9685 //
// MCU: PIC18F8722 //
// Board: BIGPIC5 //
// Power 5V. //
// Compiler: mikroC PRO for PIC version 6.6.2 //
// Programmer: On-board Mikro //
// Author: WVL //
// Date: February 2013 //
////////////////////////////////////////////////////////////////////////////////
#define Write_address 0x80 // I2C address for PCA9865 with no solder bridges
#define Read_address Write_address+1
#define PCA9685_software_reset 0x06
#define Reset 0x01 // Reset the device
#define MODE1 0x00 // 0x00 location for Mode1 register address
#define MODE2 0x01 // 0x01 location for Mode2 reigster address
#define LED0 0x06 // location for start of LED0 registers
#define ALL_CH_ON_L_reg 0xFA
#define ALL_CH_ON_H_reg 0xFB
#define ALL_CH_OFF_L_reg 0xFC
#define ALL_CH_OFF_H_reg 0xFD
#define HEARTBEAT LATH0_bit // green led on ETT board
////////////////////////////////////////////////////////////////////////////////
// Prototype functions - functions at end
void PCA9685_init();
void PCA9685_send(unsigned int value, unsigned char led);
void PCA9685AllLedOff();
unsigned char PCA9685_read_byte(unsigned char chip_register);
void PCA9685_write_byte(unsigned char chip_register, unsigned char value);
void PCA9685_write_word(unsigned char chip_register, unsigned int word_value);
void PCA9685_soft_reset();
////////////////////////////////////////////////////////////////////////////////
void main(){
// block variables
unsigned char n = 0; // LED flash
unsigned int loop = 0; // loop counter
unsigned int pwm = 0;
unsigned int x=0;
// set up ports
ADCON1 = 0b00001110; // A0 is analog
CMCON = 0b00000111; // disable comparators
// set up peripherals
I2C1_Init(100000);
PCA9685_init();
// ports
INTCON2.RBPU = 1; // PORTB pullups disabled
TRISA = 0b00000001; // A0 is A/D input
TRISC = 0b11111111; // I2C2 pins must be inputs
while(1){
// Ramp SERVO up
for(pwm=230;pwm<=902;pwm++){
PCA9685_send(pwm,1);
delay_ms(1);
}
// Ramp SERVO down
for(pwm=902;pwm>=230;pwm--){
PCA9685_send(pwm,1);
delay_ms(1);
}
// Use byte write to set LED15 to 50% duty cycle 4096/2 = 2046
// 2046 = 0x07FE so hi_byte=0x07 and lo_byte = 0xFE
PCA9685_write_byte(0x42,0); // turn on low byte
PCA9685_write_byte(0x43,0); // turn on high byte
PCA9685_write_byte(0x44,0xFE); // turn off low byte
PCA9685_write_byte(0x45,0x07); // turn off high byte
// Use word write to set LED14 to 10% duty cycle 4096/10 = 409
// 409 = 0x0199
PCA9685_Write_word(0x3E,0x0000);// turn on at time 0
PCA9685_Write_word(0x40,0x0199);// turn off at time 409 0r 0x0199
// Use byte read to get a register value
// Must bracket the shift because of precedence
x = (PCA9685_read_byte(0x45)<<8) + PCA9685_read_byte(0x44) ;
// Housekeep
HEARTBEAT = ~HEARTBEAT;
loop++;
delay_ms(20);
}
}
////////////////////////////////////////////////////////////////////////////////
// Functions
// Init the chip with pwm frequency and MODE2 settings
void PCA9685_init(){
I2C1_start(); // Start
I2C1_Wr(Write_address); // Slave Write_address
I2C1_Wr(MODE1); // Mode 1 ADDRESS
I2C1_Wr(0b00110001); // Sleep and change default PWM frequency
I2C1_stop(); // Stop
delay_ms(1); // Required 50 us delay
I2C1_start(); // Start
I2C1_Wr(Write_address); // Slave Write_address
I2C1_Wr(0xFE); // PWM frequency PRE_SCALE ADDRESS to set pwm at 100Hz
I2C1_Wr(0x3C); // Osc_clk/(4096*update_rate)=25000000/(4096*100)=60=0x3C
I2C1_stop(); // Stop
delay_ms(1); // delay at least 500 us
I2C1_start(); // Start
I2C1_Wr(Write_address); // Slave Write_address
I2C1_Wr(MODE1); // Mode 1 register ADDRESS
I2C1_Wr(0b10100001); // Set MODE1
I2C1_stop(); // Stop
delay_ms(1); // delay at least 500 us
I2C1_start(); // Start
I2C1_Wr(Write_address); // Slave Address
I2C1_Wr(MODE2); // Mode2 register ADDRESS
I2C1_Wr(0b00000100); // Set MODE2
I2C1_stop(); //
}
// Send pulse length[0-4095] to selected LED/SERVO[0-15]
void PCA9685_send(unsigned int value, unsigned char led){
unsigned char pulse_length;// temp variable for PWM
I2C1_start(); // Start
I2C1_Wr(Write_address); // address of selected pca9685
I2C1_Wr(LED0 + 4 * led); // select slected LED ADDRESS
I2C1_Wr(0x00); // LED_ON_L
I2C1_Wr(0x00); // LED_ON_H
pulse_length = value; // PWM value lo byte
I2C1_Wr(pulse_length); // LED_OFF_L
pulse_length = value>>8; // pwm 16 bit long, now shift upper 8 to lower 8
I2C1_Wr(pulse_length); // LED_OFF_H
I2C1_stop(); // stop
}
void PCA9685AllLedOff(){
I2C1_start(); // atart
I2C1_Wr(Write_address); // select pca9685
I2C1_Wr(ALL_CH_OFF_L_reg); // All LEDs Off regiter
I2C1_Wr(0b00000000); // low byte
I2C1_Wr(0b00010000); // high byte, bit4 set so full_off see page 21
I2C1_stop(); // Stop
}
// Read a byte and return it's value
unsigned char PCA9685_read_byte(unsigned char chip_register){
unsigned char temp = 0x00;
I2C1_Start();
I2C1_Wr(Write_address);
I2C1_Wr(chip_register);
I2C1_Start();
I2C1_Wr(Read_address);
temp = I2C1_Rd(0);
I2C1_Stop();
return temp;
}
void PCA9685_write_byte(unsigned char chip_register, unsigned char value){
I2C1_Start();
I2C1_Wr(Write_address);
I2C1_Wr(chip_register);
I2C1_Wr(value);
I2C1_Stop();
}
// Write 16bits to chip_register, increments automatically from lo to hi byte
void PCA9685_write_word(unsigned char chip_register, unsigned int word_value){
unsigned char hb = 0x00;
unsigned char lb = 0x00;
lb = (word_value & 0x00FF);
hb = ((word_value & 0xFF00) >> 0x08);
PCA9685_write_byte(chip_register,lb);
PCA9685_write_byte((chip_register+1),hb);
}
// Soft re-set
void PCA9685_soft_reset(){
I2C1_Start();
I2C1_Wr(0x00);
I2C1_Wr(PCA9685_software_reset);
I2C1_Stop();
}Regards Bill Legge
