GTA04: Add demo script for running the vibrator

Signed-off-by: NeilBrown <neilb@suse.de>

2 files changed, 74 insertions, 0 deletions

diff --git a/GTA04/README b/GTA04/README
index f70870f..dad8c0a 100644
--- a/GTA04/README
+++ b/GTA04/README
@@ -24,3 +24,7 @@
   then the uImage and modules are in 'M' ready to be copied
 
 
+- Directory 'scripts' includes some sample scripts to various
+  simple tasks
+
+  + vibra.py shows how to program the vibrator as a rumble effect.
diff --git a/GTA04/scripts/vibra.py b/GTA04/scripts/vibra.py
new file mode 100644
index 0000000..c33f0a0
--- /dev/null
+++ b/GTA04/scripts/vibra.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+
+import fcntl, struct, time, array
+
+#
+# There are two steps to creating a rumble effect
+# 1/ describe the effect and give it to the driver using an
+#    ioctl.
+#   There a 3 paramaters:
+#     strength:  from 0 to 0xffff - this code takes a value from 0 to
+#                                   1 and scales it
+#     duration: milliseconds
+#     delay until start: milliseconds.
+#
+# 2/ write a request to play a specific effect.
+#
+# It is possible to have multiple effects active.  If they have
+# different delays they will start at different times.
+# This demo shows combining 3 non-overlapping effects to make
+# a simple vibration pattern
+#
+# An effect is created with f.new_vibe(strength, duration, delay)
+# That effect can then be started with 'play' and stopped with 'stop'.
+
+class Vibra:
+    def __init__(self, file = "/dev/input/rumble"):
+        self.f = open(file, "r+")
+
+    def new_vibe(self, strength, length, delay):
+        # strength is from 0 to 1
+        # length and delay are in millisecs
+        # this is 'struct ff_effect' from "linux/input.h"
+        effect = struct.pack('HhHHHHHxxHH',
+                             0x50, -1, 0, # FF_RUMBLE, id, direction
+                             0, 0,        # trigger (button interval)
+                             length, delay,
+                             int(strength * 0xFFFF), 0)
+        a = array.array('h', effect)
+        # this is EVIOCSFF _IOC(_IOC_WRITE, 'E', 0x80, sizeof(struct ff_effect))
+        fcntl.ioctl(self.f, 0x402c4580, a, True)
+        id = a[1]
+        # this is 'struct input_event': sec, nsec, type, code, value
+        ev_play = struct.pack('LLHHi', 0, 0, 0x15, id, 1)
+        ev_stop = struct.pack('LLHHi', 0, 0, 0x15, id, 0)
+        return (ev_play, ev_stop)
+
+    def play(self, ev):
+        p,s = ev;
+        self.f.write(p)
+        self.f.flush()
+
+    def stop(self, ev):
+        p,s = ev;
+        self.f.write(s)
+        self.f.flush()
+
+
+
+f = Vibra("/dev/input/rumble")
+
+# rumble for 300ms, pause for 100ms, rumble for 300ms, pause for 200ms
+# then half-speed rumble for 600ms
+p1 = f.new_vibe(1, 300, 0)
+p2 = f.new_vibe(1, 300,400)
+p3 = f.new_vibe(0.5, 600, 900)
+f.play(p1)
+f.play(p2)
+f.play(p3)
+
+time.sleep(1.5)