Selecting Autonomous with TI LaunchPad?

[team-4480]

Hi,

We are going to make a nice control box with random buttons and potentiometers using the TI MSP430 LaunchPad. We want to be able to select an autonomous mode with a dial using one of the potentiometers through the LaunchPad.

The problem is, how do I send what the choice is to the robot if the LaunchPad is seen as a gamepad?

Should I write a pygame script and use pynetworktables to send the choice from it? Or is there a much simpler way that I am overlooking? How do other teams do it?

Any help would greatly be appreciated!

[RufflesRidge]

Originally Posted by team-4480

Or is there a much simpler way that I am overlooking?

You can just read the value of the "joystick axis" that corresponds to the potentiometer analog input and use that to determine the choice.

[asid61]

Why not simply use a multiposition button? They look like potentiometers but have different settings you can snap to rather than an analog output.
Apart from that, reading it as a joystick or just running some kind of direct voltage reading would work.

[Max Boord]

Originally Posted by asid61

Why not simply use a multiposition button? They look like potentiometers but have different settings you can snap to rather than an analog output.

This is how 1065 has selected auto modes for years now. 1 or 2 multi position dial and a toggle switch if needed. This year for instance we used the dial to select what we where driving over and position and then used a 3 position switch to determine if we would shoot high, low or do nothing once we got to the batter.

[jSchnitz]

Originally Posted by RufflesRidge

You can just read the value of the "joystick axis" that corresponds to the potentiometer analog input and use that to determine the choice.

It sounds like he is worried that the robot won't be able to read the joystick axis in autonomous since it is, well, autonomous. I don't actually know if this is the case or not.

NetworkTables would work just fine for sending the choice. Alternately your code could read the joystick axis in a periodic function, or in disabled, and then use the value from there in autonomous.

[Thad House]

At the beginning of autonomous, the FPGA latches the most recent joystick values received. So you can read joystick values in autonomous as long as you have set them properly before autonomous.

[Christopher149]

Originally Posted by Thad House

At the beginning of autonomous, the FPGA latches the most recent joystick values received. So you can read joystick values in autonomous as long as you have set them properly before autonomous.

This. We have 5 rocker switches that we wired to buttons 1 through 5 on the Launchpad, and just read the button states at the beginning of autonomous like a boring old joystick. Easy and simple.

(our biggest problem has been with the physical construction of our wiring to the buttons coming undone - we should redo it)

[team-4480]

Originally Posted by jSchnitz

It sounds like he is worried that the robot won't be able to read the joystick axis in autonomous since it is, well, autonomous. I don't actually know if this is the case or not.

NetworkTables would work just fine for sending the choice. Alternately your code could read the joystick axis in a periodic function, or in disabled, and then use the value from there in autonomous.

You hit the nail on the head. I just wasn't sure if I would be able to grab the latest value from the joystick, but it sounds like you can from the reponses. Thanks!

[Alan Anderson]

In the "old days" when the joystick values were all returned during autonomous as neutral with no buttons pressed, the typical tactic was for the user program to read and save the values while the robot was disabled before the match began, then use the saved values during autonomous. That is now done for you by the system.

[sraque]

Originally Posted by Alan Anderson

In the "old days" when the joystick values were all returned during autonomous as neutral with no buttons pressed, the typical tactic was for the user program to read and save the values while the robot was disabled before the match began, then use the saved values during autonomous. That is now done for you by the system.

Is there a document somewhere that captures this, and similar, system design information?

[messer5740]

My team was considering doing this. Would the TI LaunchPad Evaluation kit work? Also, how would you make it work? Would you wire it to the RoboRio or to a different module?

[Mark McLeod]

Originally Posted by messer5740

My team was considering doing this. Would the TI LaunchPad Evaluation kit work? Also, how would you make it work? Would you wire it to the RoboRio or to a different module?

See this Launchpad thread to get started.

[adciv]

If you're open to an alternative method... We set our options this year by creating custom buttons/drop boxes on the dashboard. Our drive team would configure auto as required at the setup and network tables would sent the info to the robot. This can make things a tad simpler at times (we had at least three options to set this year).

[team-4480]

Originally Posted by adciv

If you're open to an alternative method... We set our options this year by creating custom buttons/drop boxes on the dashboard. Our drive team would configure auto as required at the setup and network tables would sent the info to the robot. This can make things a tad simpler at times (we had at least three options to set this year).

Yea we did something similar using the SmartDashboard. Personally, I think having physical switches are awesome so we are going to give it a shot.

[GreyingJay]

We put a multiposition selector switch right on the robot. It's a 12-position dial (with a nice solid click-click-click action) and a built in LED that lights up which position is selected. Internally it is a resistor ladder so you read it as an analog input on the RoboRio. Worked very well for us. The drive team literally dials in which autonomous they want to run before each match.