prh: new example config to latch a non-motorised fader

1 files changed, 51 insertions, 0 deletions

diff --git a/configs/latch.lua b/configs/latch.lua
new file mode 100644
index 0000000..569cae2
--- /dev/null
+++ b/configs/latch.lua
@@ -0,0 +1,51 @@
+-- Trackpad input by Paul Hedderly
+-- Expects two inputs - one master and one slave
+-- The first is to track a contolled input for example a
+-- sound desk fader.
+-- The slave is for a fader on a non-motorised surface...
+-- The idea is that the slave is not forwarded to the
+-- first/main output until it is close in value to the master
+-- This is to avoid sudden jumps when using a secondary
+-- non-motorised controller.
+--
+-- Example config - here using a nanok as a slave to an X32
+--
+--	[midi x32]
+--	read = X32Live
+--	write = X32Live
+--
+--	[midi nanoK]
+--	read = nanoKEY
+--	write = nanoKEY
+--
+--	[lua latch]
+--	script = latch.lua
+--	default-handler = latch
+--
+--	x32.ch0.cc1 > latch.0.master
+--	nanoK.ch0.cc1 > latch.0.slave
+--	latch.0.latched > x32.ch0.cc1
+
+threshold=0.03
+saved={}
+
+function latch(v)
+	i=input_channel(); separator=i:find("%.")
+	channel=i:sub(0,separator-1)
+	control=i:sub(1+separator,-1)
+
+	-- Setup the saved value if not yet seen
+	if saved[channel]==nil then
+		saved[channel]=v
+	end
+
+	if control == "master" then
+		saved[channel]=v
+	elseif control == "slave" then
+		diff=math.abs(v-saved[channel])
+		if diff < threshold then
+			saved[channel]=v
+			output(channel..".latched",v)
+		end
+	end
+end