One way to do this is to use more selects such that when a limit switch is pressed, it allows the value to be anywhere within a range that is either stopped or goes the other way. Now, this is good, but we wanted the limit switches to turn off the motor at its limits, so let’s add that in. Let’s start simple and use two buttons and some selects to set the motor. To allow this VI to execute as quickly as possible, we will rely on the calling VI to provide the DevRef’s as opposed to Refnums. We are assuming that the hardware has already been opened. In this example, we are constructing a vi, that can be called frequently to set the values of the motor based on joystick input, and we will add front panel controls in to allow for running this VI in Autonomous and passing in constants to control the motor.įor an example on having a motor remain in a state until a new input, we will refer you to our State Machine Tutorial Block Diagram If you find the switch reports true when you expect false and false when you expect true, change the value of the Normally Closed input for that switch. They work similarly to the Invert constant on the Motor Open VI. Notice the Normally Closed false constants connected to the Limit Switch Open VIs. For this example, we will use two limit switches, a joystick, and a motor. Just a formality, but we will start by opening the necessary hardware in Begin.vi. This will allow this VI to be used in Autonomous and/or Teleop, or if it needs to be run all the time, can be placed in Periodic Tasks. Insertable VIįor the sake of this tutorial, we will construct a VI that takes in the DevRef’s for each piece of hardware associated with this example, and performs the logic to set the motor. Image from the FRC Limit Switch example installed with LabVIEW for FRC. When the Signal and Ground wires connect, the Signal wire voltage is pulled low more firmly. It may seem odd to use the Ground pin instead of the 5V pin on the roboRIO but behind the scenes the Signal wire voltage is being pulled high when not connected to anything. For example, in a security system the NC terminal would be preferred since if someone were to cut one of the wires, the circuit would break triggering the system (know there may be even better systems than that). However, there are some cases when you would want to use the NC terminal. In general choose the NO terminal as that makes the circuit on when the switch is pressed, and off when the switch is not pressed which makes the most since to most peoples’ brains. WiringĬonnect the Signal and Ground pins from a DIO port to the COM (Common) and either NO (Normally Open) or NC (Normally Closed) terminals on a switch.
#VEX LIMIT SWITCH ROBORIO SOFTWARE#
It is possible to configure hardware using limit switches and Talons, so that the limit switch directly inputs to the Talon, but presented here is a software solution. It is often advantageous to use limit switches to set how far an actuator can go. FRC LabVIEW Tutorials - Limit-Switch - RoboRIO Using Limit Switches
0 kommentar(er)
