[Mark McLeod]

1. Start with a default project (you can add other stuff if you want to).
2. Look in Teleop.vi for the DB/Button 1 code (with the Sample Boolean 1 output)
3. Copy that snippet of code to the Vision Processing.vi, inside the While loop
4. Add a separate Case statement inside the While Loop
5. Wire the same output that feeds the Sample Boolean 1 output to the Case
6. Copy the Camera Set Expos into the Case True case.
7. Wire the Set Expos to the pink camera ref that comes in the left of the While Loop
8. Change the Set Expose input constant to "Hold current"

Once you've put the new code onto the roboRIO, go to the Dashboard Basic tab and press DB/Button 1 to make the camera Hold Current exposure setting.
This would only work once and assumes that the original Set Expos is still set to "Auto".
Once set to Hold current exposure, then if you push the button a second time you won't se any change.
To get it to change again you'd need to add another Set Expos to take it back to "Auto" long enough for the camera to adjust the exposure again, then you could Hold Current again.