Thanks for the attention, I need a little help.
The problem is the following, I managed to communicate with my Arduino by rosserial.
The thing is that it works, it receives the message that is the PWM frequency for the stepper motors. However, it spins without control. I tried the chatter to print frequency. I tried many different possibilities and it did not work. I would like to know how to get control over my motors.
I am using a library called **PWM frequency library** .
This is the code I am using on my arduino:
#include
#include
#include
#include
#include //PWM library for controlling the steppers
//#include //not sure about this for the int32_t
ros::NodeHandle nh;
std_msgs::Int32 str_msg;
ros::Publisher chatter("debug", &str_msg);
//Motor pins
//use pin 11 on the Mega instead, otherwise there is a frequency cap at 31 Hz
const int step_pin1 = 11; // the pin that define the steps
const int dir_pin1 = 22; // the dir pin
const int step_pin2 = 12; // the pin that define the steps
const int dir_pin2 = 24;
int32_t frequency1 = 0; //frequency (in Hz)
int32_t frequency2 = 0; //frequency (in Hz)
bool dir1 = true;
bool dir2 = true;
void driveCallback ( const geometry_msgs::Twist& twistMsg ){
//need to pubish straigth the motor commands and do the dir calculations on the Arduino
frequency1 = abs( (int)twistMsg.linear.x ) ;//work as motor1_cmd_callback ---- twistMsg.linear.x must already be converted to int32_t
frequency2 = abs( (int)twistMsg.linear.y ) ;//work as motor2_cmd_callback ---- twistMsg.linear.y must already be converted to int32_t
// SetPinFrequency(step_pin1, frequency1); //change for the callback function of motor1_cmd
// SetPinFrequency(step_pin2, frequency2); //change for the callback function of motor2_cmd
str_msg.data = frequency1;
chatter.publish(&str_msg);
if(twistMsg.linear.x >= 0){
dir1 = true;
//digitalWrite(dir_pin1, HIGH);
}
else{
dir1 = false;
//digitalWrite(dir_pin1, LOW);
}
if(twistMsg.linear.y >= 0){
dir2 = true;
//digitalWrite(dir_pin2, HIGH);
}
else{
dir2 = false;
//digitalWrite(dir_pin2, LOW);
}
}
ros::Subscriber driveSubscriber("comm_drive_robot", &driveCallback) ;
void setup(){
//initialize all timers except for 0, to save time keeping functions
InitTimersSafe();
nh.initNode();
// Subscribe to the steering and throttle messages
nh.subscribe(driveSubscriber);
nh.advertise(chatter);
// =======================================================================================
/* ================ PWM Function ======================================================= */
//PWM + direction to the motors 1
pinMode(step_pin1, OUTPUT);
pinMode(dir_pin1, OUTPUT);
//PWM + direction to the motors 2
pinMode(step_pin2, OUTPUT);
pinMode(dir_pin2, OUTPUT);
//SetPinFrequency(step_pin1, frequency1); //change for the callback function of motor1_cmd
//SetPinFrequency(step_pin2, frequency2); //change for the callback function of motor2_cmd
if(dir1 == true){
digitalWrite(dir_pin1, HIGH);
SetPinFrequency(step_pin1, frequency1); //change for the callback function of motor1_cmd
pwmWriteHR(step_pin1, 32768);
}
else{
digitalWrite(dir_pin1, LOW);
SetPinFrequency(step_pin1, frequency1); //change for the callback function of motor1_cmd
pwmWriteHR(step_pin1, 32768);
}
if(dir2 == false){
digitalWrite(dir_pin2, HIGH);
SetPinFrequency(step_pin2, frequency2); //change for the callback function of motor2_cmd
pwmWriteHR(step_pin2, 32768);
}
else{
digitalWrite(dir_pin1, LOW);
SetPinFrequency(step_pin2, frequency2); //change for the callback function of motor2_cmd
pwmWriteHR(step_pin2, 32768);
}
}
void loop(){
nh.spinOnce();
delay(1);
}
↧
