Monday, 9 May 2011

USB servo board - almost done?

This is looking like the final version of the servo board and includes a number of cool enhancements:

At any point in the script, the user can place a label.
This is marker point from where you can play back sections of an animation.
Users can place GOTO commands in the script, such as "goto 1500ms" (the animation jumps to the point 1.5 seconds into the animation) or "goto label 4". It is this second GOTO command that makes the servo board so useful:

We've also updated the firmware so that one or more of the servo pins can be used as input triggers. Simply tell the board how many input pins you want to use (0-8) and when the appropriate input pin is pulled low, the animation playback jumps to that label number.

For example, pull the first input pin (normally servo 20) low and playback immediately jumps to label 1. Pull the second input pin low (normally servo 19) and playback jumps to label 2. Because our servo pins have ground on the outside and signal on the inner (the middle pin is always 5v) the button in the video simply bridges the two outer pins, to pull the input pin low.

Here's the full script, as used in the video above:

'this is the first animation
'it can also be triggered by sending PORTB.7 low

label 500,1
servo 1000,9,50
servo 1000,10,50
servo 2000,9,220
servo 2000,10,220
servo 3000,9,50
servo 4000,10,50
servo 5000,10,220
servo 6000,9,220
tloop 7000,1000 'go to time point 1000

'this is the second animation loop
'triggered when PORTB.6 goes low

label 10000,2
servo 10000,9,150
servo 10000,10,150
servo 11000,9,220
servo 11000,10,50
lloop 12000,2 'go to label 2

end 15000