Changes between Version 6 and Version 7 of WikiStart

Timestamp:

2013-08-18 08:59:18 (11 years ago)

Author:

gengen

Comment:

--

WikiStart

@@ -66 +66 @@
 This is a hybrid Vera device. Most devices in Vera are either Z-Wave or Lua devices. The Evolve LCD1 is both. In order to do this, two devices are created: The "Z-Wave device" and the "Peer device" but only the peer device is displayed in the main UI5 devices page or on the dashboard. (This is different from the typical parent-child relationship in other plug-in devices.) This dual-device strategy works around a limitation in the Vera architecture whereby Z-Wave devices cannot execute Lua commands. It also allows us to dispatch different scenes depending on what screen mode the device is in.
 
+Sending screen updates to the LCD too quickly can cause lines of test to be lost, garbled, or placed in the wrong spot. Unfortunately, the delay required to avoid such errors is variable and choosing the maximum "safe" delay would cause screen redraws to be very slow. Furythermore, the device, does not give any feedback as to when it is safe to draw the next part of the screen. To solve this problem starting in version 0.7, the plug-in sends a dummy request to the controller. The controller will not respond if it is not yet ready and the plug-in will retry drawing that chunk with a bit more delay. Unfortunately, the only requests that pass through the Z-Wave chip on the device and onto the display microcontroller are not understood by Vera, and the current Vera firmware has no good method to pass such unknown messages to Lua code. Instead, the plug-in enables Z-Wave data received messages (log level 42) if they are not already enabled, and monitors the log for the expected response. This is an incredible hack but it is the only thing that works after many failed attempts at a more elegant solution.
+
+== Tuning Parameters ==
+
+In the Advanced tab, you will find various tuning parameters which may be used to improve performance. The values of these parameters may depend on how far your LCD controller is away from Vera as well as the firmware version of the controller. When you first create the device one of two sets of parameters is chosen depending on whether the firmware version is greater than 0.31 or not. This plug-in was developed mostly with firmware version 0.37. All delay parameters are in milliseconds
+
+||= Parameter =||= Meaning =||= 0.31 default =||= 0.37 default =||
+|| LCD_BaseDelay || Delay after redrawing any chunk of the screen || 2000 || 100 ||
+|| LCD_ClearDelay || Delay after clearing the screen || 0 || 500 ||
+|| LCD_LineDelay || Delay after redrawing each line of the screen || 0 || 100 ||
+|| LCD_CharDelay || Delay after redrawing each character of the screen || 0 || 10 ||
+|| LCD_ResponseDelay || Time needed to wait for a response after displaying a chunk || 30 || 30 ||
+|| LCD_BackoffDelay || Delay to add after each failed attempt to draw a chunk || 50 || 50 ||
+|| LCD_MaxParts || Maximum secions to draw in one chunk. Can be 1 or 2 || 1 || 2 ||
+|| LCD_UseClearScreen || 1 to clear the whole scree, 0 to clear individual lines || 1 || 1 ||
+|| LCD_Retries || maximum number of retries if redraw fails || 10 || 10 ||
+|| ShowSingleDevice|| 0 to show both the Z-Wave and peer devices in UI5 || 1 || 1 ||
 
 Enjoy! [[BR]]
+
 ''Gengen''