TETRIX MAX Servo Expansion Controller Block for EV3

 

This block interfaces TETRIX MAX standard and continuous rotation servo motors with an EV3 sensor port.

 

EV3 Connection:

 

To ensure proper port identification, connect and power the TETRIX controllers before powering the EV3 brick. The EV3 will display an error flag over the port parameter of the block if the devices are not powered in this sequence. If communications with the expansion controller is not working, unplug and plug the sensor cable back in to reset communications. Refer to the end of this document for connection and controller mounting diagrams.

For best functionality of the TETRIX Servo expansion controller block, DO NOT use multi-thread programming methods.

Block Anatomy:

 

 

1.     Port Selector

2.     Mode Selector

3.     Input

4.     Output

 

Use the Port Selector on the top of the block to make sure that the sensor port number (1, 2, 3, or 4) matches the port on the EV3 Brick that the motor controller is connected to.

Use the Mode Selector to select the mode for the block. The inputs, outputs and next action parameters available will change depending on the mode.

 

 

Modes:

 

Read Servo Position


Returns the position of the servo.

 

Move


Moves the desired servo to a user-defined position.

 

Set Servo Speed


Sets the speed of all servos.

 

 

Inputs and Outputs:

 

The inputs available for the TETRIX Servo expansion controller block will depend on the mode selected. You can enter the input values directly into the block. Alternatively, the input values can be supplied by data wires from the outputs of other programming blocks.

 

Input

Type

Allowed Values

Description

Servo

Numeric

1-6

1: Servo Channel 1
2: Servo Channel 2
3: Servo Channel 3
4: Servo Channel 4
5: Servo Channel 5
6: Servo Channel 6

Position

Numeric

0-180 (degrees)

Determines the position at which to set the servo motor shaft in degrees.
0: Minimum servo position
180: Maximum servo position

Servo Speed

Numeric

0-100 (percent)

Sets the speed for all servo channels. A value of 0 is the minimum rate. A value of 100 is the maximum rate. This block can be executed anytime the servo speeds need to be changed.

 

 

The outputs available will depend on the mode selected. To use an output, use a data wire to connect it to another programming block.

 

Output

Type

Description

Position

Numeric integer

Returns the position of the selected servo in degrees (0-180).

 

 

Connections and Mounting:

 

 

 

 

Daisy-chaining multiple controllers:

 

DC and Servo motor expansion controllers can be connected to a single EV3 sensor port in a daisy chain configuration as shown below. Additional controllers may be added to other sensor ports in the same arrangement.