How to program ESC to increase/decrease PWM in increments - arduino

Question

I've coded with Python before however, I am in the process of learning C and from what I have been told Arduino is quite similar to C in some aspects (at least with coding). I noticed that my when I run the code on my robot it jolts due to the quick changes in PWM. So I'd like some guidance as to how to do an if statement on Arduino because I am trying to increase/decrease the PWM in increments.
//On Roboclaw set switch 1 and 6 on. // <-- what does this refer to?
//mode 2 option 4 // <-- my note based on user manual pg 26
#include <Servo.h>
Servo myservo1; // create servo object to control a Roboclaw channel
Servo myservo2; // create servo object to control a Roboclaw channel
//int pos = 0; // variable to store the servo position //<-- left-over from arduino ide servo sweep example?
void setup()
{
myservo1.attach(9); // attaches the RC signal on pin 5 to the servo object (Left Motor)
myservo2.attach(11); // attaches the RC signal on pin 6 to the servo object (Right Motor)
}
void loop()
{
//forward
myservo1.writeMicroseconds(1000);
myservo2.writeMicroseconds(1000);
delay(2000);
//backward
myservo1.writeMicroseconds(2000);
myservo2.writeMicroseconds(2000);
delay(2000);
//left
myservo1.writeMicroseconds(1500);
myservo2.writeMicroseconds(1000);
delay(2000);
//right
myservo1.writeMicroseconds(1000);
myservo2.writeMicroseconds(1500);
delay(2000);
}

Answer 1

Ok, whenever you write a different value to the servo it will move to that position as fast as possible. So you will need to move your servo step by step.
For this task, however, you will not be able to use delays, since they block the processor. You will need to mimic the "blink with no delay" example (i.e. using the millis() function to do something when time passes by.
The acceleration control simply moves 1° every X milliseconds (in this case 6ms, which makes a full movement - 180° - last for about one second). Every X milliseconds, so, the uC moves 1° in the direction of a target position. In the other code you should just set the target to your desired position and you are done.
Here is the code I wrote. Let me know if it works for you
#include <Servo.h>
Servo myservo1;
Servo myservo2;
unsigned long prevMillisAccel = 0, prevMillisAction = 0;
uint8_t servo1_target;
uint8_t servo2_target;
uint8_t currAction;
#define TIME_FOR_ONE_DEGREE_MS 6
void setup()
{
myservo1.attach(9)
myservo2.attach(11);
prevMillisAccel = millis();
prevMillisAction = millis();
servo1_target = 0;
servo2_target = 0;
myservo1.write(0);
myservo2.write(0);
currAction = 0;
}
void moveServoTowardsTarget(Servo *servo, uint8_t target)
{
uint8_t pos = servo->read();
if (pos > target)
servo->write(pos-1);
else if (pos < target)
servo->write(pos+1);
}
void loop()
{
unsigned long currMillis = millis();
if (currMillis - prevMillisAccel >= TIME_FOR_ONE_DEGREE_MS)
{
prevMillisAccel += TIME_FOR_ONE_DEGREE_MS;
moveServoTowardsTarget(&myservo1, servo1_target);
moveServoTowardsTarget(&myservo2, servo2_target);
}
if (currMillis - prevMillisAction >= 2000)
{
prevMillisAction += 2000;
currAction = (currAction + 1) % 4;
switch(currAction)
{
case 0: // forward
servo1_target = 0;
servo2_target = 0;
break;
case 1: // backward
servo1_target = 180;
servo2_target = 180;
break;
case 2: // left
servo1_target = 90;
servo2_target = 0;
break;
case 3: // right
servo1_target = 0;
servo2_target = 90;
break;
}
}
}
PS. I used the write function instead of the writeMicroseconds because you can read the value you wrote. If you really need to use writeMicroseconds (which is pretty useless in my opinion, since servo precision is less than 1°, so write is more than sufficient) just store the target as a uint16_t and store also the last set value (and use that instead of the read function)