VM8201 with RAMPS 1.4

Many of us have had reason to replace the controller for the K8200 with an Arduino MEGA2560 and a RAMPS 1.4 board, whether due to board failure, or to support a printer upgrade as I did when I built a dual extruder K8200. The one loose end for me has been how to connect the VM8201 LCD/SD Card Stand-Alone Controller back up to the RAMPS board?

I finally did some research, squinting at schematics and poring over firmware to get this working. I thought I would document it here for anyone else looking to do this.

The RAMPS1.4 board brings out a number of Arduino I/O pins to connector AUX-4, which is a single row of pins along the edge of the board that is away from the power and USB connectors. The display will use the top 10 of these pins, plus six of the pins on the AUX-3 connector on the corner of the RAMPS board.

NOTE: The 18-pin connector on the VM8201 is labelled with Arduino pin designations that do not appear to correspond to the actual pins being used. I also found conflicting documentation about the Arduino pin designations on the RAMPS board.

VM8201 18-pin connector:

                     SK2
                  +-------+
           GND ---+ 2   1 +--- PC4 === DB6 LCD (D27)
          (12V)---+ 4   3 +--- PH1 === EN2 (D37)
            5V ---+ 6   5 +--- PH0 === EN1 (D35) 

(D25) DB5 LCD === PC2 —+ 8 7 ±-- PA5 === RS LCD (D16)
(D23) DB4 LCD === PC0 —+10 9 ±-- PA7 === EN LCD (D17)
(D29) DB7 LCD === PC6 —+12 11±-- PA1 === ENC PB (D23)
MOSI —+14 13±-- PA3 === SDSS (D53)
(SS)—+16 15±-- SCK === SCLK
(RST)—+18 17±-- MISO ===
±------+

RAMPS AUX-4
----+
D16 ±-- RS LCD (PA5)
D17 ±-- EN LCD (PA7)
D23 ±-- DB4 LCD
D25 ±-- DB5 LCD
D27 ±-- DB6 LCD
D29 ±-- DB7 LCD
D31 ±-- ENC PB (PA1)
D33 ±-- n.c.
D35 ±-- EN2 (PH1)
D37 ±-- EN1 (PH0)
… +
… +
… +
… +
… +
… +
… +
… +
----+

RAMPS AUX-3
±------------------------+
| GND SCK MISO 5V |
| n.c. D53 MOSI (D49) |
±------------------------+

This new BB software is terrible. I cannot edit this post to be readable, can’t seem to delete it, and this is more trouble than it is worth. If you have any questions, please ask and I’ll do my best to clarify.

Happy printing. :frowning: