Gamepad¶

(gamepad 1) and (gamepad 2) return what the controller is doing right now, as a map. The keys are the FTC SDK's Gamepad field names as kebab-case keywords:

user=> (:a (gamepad 1))
false
user=> (:right-trigger (gamepad 1))
0.8

A, B, X and Y are :a, :b, :x and :y, each true or false. LT and RT are :left-trigger and :right-trigger, from 0.0 to 1.0. Destructuring names several at once:

user=> (let [{:keys [a b x y]} (gamepad 1)] [a b x y])
[true false false true]

The sticks are :left-stick-x, :left-stick-y, :right-stick-x and :right-stick-y:

user=> (let [{:keys [left-stick-x left-stick-y]} (gamepad 1)]
         [left-stick-x left-stick-y])
[0.0 -0.35]

The values are not adjusted from what the SDK reports. As in FTC, pushing a stick forward gives a negative :left-stick-y. To turn that into a forward motor power, negate it; see the threading example in Functions.

A map is a snapshot: it never changes afterwards. Call (gamepad 1) again to see new input.

Watching¶

To see A, B, X, Y, LT and RT while you press them, take a fresh snapshot each round and put it on the Driver Hub:

(defn show-gamepad []
  (loop []
    (let [pad (gamepad 1)]
      (telemetry/clear)
      (telemetry/add-line "A" (:a pad) "B" (:b pad) "X" (:x pad) "Y" (:y pad))
      (telemetry/add-line (format "LT %.2f  RT %.2f"
                                  (:left-trigger pad) (:right-trigger pad)))
      (time/sleep 0.02)                  ; about 50 snapshots a second
      (recur))))

Start it in the background with (control/start show-gamepad) and end it with (control/stop); see Control Loops. The Driver Hub then shows the values changing as you press buttons:

A true B false X false Y false
LT 0.00  RT 0.42

telemetry/clear each round replaces the previous lines instead of piling them up, and the two spaces in the format keep the LT/RT line from jumping around (see Telemetry).

gamepad exists only on the robot. LocalRepl leaves the name unresolved, so try these calls on the robot.