Control for servos

The servo control allows you to manage analog and digital servos easily and economically.
The control is entrusted to the 8-bit "12F1571" microprocessor from Microchip, it:

• monitors the state of the input for the button;
• it takes the angular position and the movement speed from the two trimmers;
• generates a PWM signal for motor controls.

The opening angle can be adjusted by acting on the " CORNER " trimmer, turning to the left, the servo opening angle increases, turning to the right, the opening angle decreases.
The movement speed is adjustable by acting on the “ SPEED 'trimmer, turning to the right, the speed decreases, turning to the left, the speed of the servo increases.
The " SJ1 " jumper allows you to select the operating mode:

• SJ1 closed: button operation;
• SJ1 open: operation with switch;

The jumper must be closed with a weld.

We attribute the name SERVO2 to the servo wired on the single connector, and SERVO1 to that wired to the double connector; as soon as power is supplied to the circuit, SERVO1 moves to the rest position with an angle of 0 °, while SERVO2 moves to the rest position with an angle of 180 °.
By pressing the button that activates their movement, the two servos begin to move with the speed set by the " SPEED " trimmer and continue the run until they reach the angle set with the " ANGLE " trimmer.
Ex:

• movement angle set at 40 °, SERVO1 assumes an angle of 40 ° while SERVO2 of 140 °;
• displacement angle set to 170 °, SERVO1 assumes an angle of 170 ° while SERVO2 of 10 °;

After carrying out all the connections above, proceed as follows for the adjustment:

• turn the trimmers (ANGLE and SPEED) to the central position;
• Supply power to the circuit (the actuators moves to the initial position, i.e. the rest position);
• press the button or switch wired on the SWITCH input (the actuators rotate to the open position regulated by the trimmer);
• Act on the ANGLE trimmer to adjust the desired opening angle and act on the SPEED trimmer to adjust the execution speed.

• Home automation;
• Automotive;
• Robotics;
• Modeling;

1. continuous displacement ; in this configuration the servo performs a continuous forward and backward movement until the button or switch remains closed, the angle and the speed of rotation can be adjusted by trimmer.

2. continuous movement with central rest position ; in this configuration the servo performs a continuous movement (+ -90 ° max), starting from a central rest position (0 °); the angle and the speed of rotation are adjustable by trimmer.

3. shift with two buttons ; in this configuration the servo performs a classic movement with the only variation of using a second key to return to the rest position; the angle and the speed of rotation are adjustable by trimmer. NB: in this variant it is possible to use only buttons and not switches, the output for the servo in push-pull is not available as it is used to accommodate the second button.

4. DX / SX movement with two buttons and central rest position ; in this configuration the servo is in the central position and performs a movement towards the right or left of a maximum of 90 ° according to the key pressed; the angle and the speed of rotation are adjustable by trimmer. NB: in this variant it is possible to use only buttons and not switches, the output for the servo in push-pull is not available as it is used to accommodate the second button.

5. shifting with two buttons of two distinct angles ; in this configuration the servo performs two movements depending on the key pressed; the angle of the single movement is adjustable by trimmer. NB: in this variant it is possible to use only buttons and not switches, the output for the servo in push-pull is not available as it is used to accommodate the second button, the speed of execution of the movement is fixed at maximum speed because the trimmer for the speed is used for the angle of the second displacement.

6. shifting with a button of two distinct corners in succession ; in this configuration the servo performs two movements with two distinct angles in succession; the angle of the single movement is adjustable by trimmer. NB: in this variant it is possible to use only buttons and not switches, the execution speed of the movement is fixed at the maximum speed because the speed trimmer is used for the angle of the second movement.