The SAV 3D LCD is an LCD with rotary encoder with click button and 2 push buttons to control your LCD. It allows the control of a 3D printer running Marlin firmware and a SAV MkI, sanguinololu, printrboard or similar electronics directly without having to have a computer connected.
Standard features are provided by marlin firmware all of which are fully operational: start and stop prints, control print speed while printing and change many calibration settings - saving these to the AVR’s EEPORM so they are persistent if you turn the printer on and off -. The design also counts with an enclosure box that can be mounted on your printer.
This module does not have an SD reader as this feature is provided by the SAV MkI, making the LCD interface more reliable and glitch free. The module connects to the main controller using a 14 wire ribbon cable using a 3M box connector. The LCD has been tested with a 1.5m ribbon cable without glitches.
The LCD module comes with an expansion module to connect directly to the SAV MkI. Not only does it allow you to connect the SAV with the LCD backpack but it also expands the control to an external 5V device such as a servo for auto-bed levelling. The device's 5V supply comes from a dedicated voltage regulator, this will avoid any interference caused by it (servo) with your board's 5V supply rail.
The entire LCD is controlled using 2 wires through a Shift Register (SR) interface, the rotary encoder has filtered outputs and relying on the internal AVR pull-ups.
The LCD is a derivative of electroFUN’s Shift Register LCD (SR LCD) which uses only 2 wires to control the LCD, however with the right library (New LiquidCrystal library by fmalpartida) is 4 times faster than the stock LCD driver.
|LCD type||Hitachi HD44780 alphanumeric, 20x4, Blue background white text|
|LCD interface||2 wire shift register|
|Control||Quadrature rotary encoder with push button, 24 PPR|
|Push button||2 (predefined for KILL and HOME)|
|Connection||3M boxed connector to LCD and expansion module 14 wire ribbon cable|
|Expansion module||1 IO|
|5V regulated output||62dB ripple rejection - Typ|