Errors in the documentation for the MKS GEN_L 1.0 motherboard (EXP1 & EXP2)

AETEK

Hello,
Unfortunately there are again errors in the documentation for the MKS GEN_L 1.0 motherboard. I can not say if there are more errors because I have not checked every pinout. I have found the errors listed here, because in the context of my hardware development, I encountered again and again strange problems. Due to my confidence in my ability in hardware and software development (already 35 years), the problem had to be elsewhere.
I do not want to make the MKS motherboard bad. It is in my opinion a solid hardware and very cheap to buy. The fact that the documentation contains errors is not surprising in a version 1.00.

Today it's about the EXP1 and EXP2 ports. At these connections one can operate a monochrome text or graphic display.

This should be very easy after the MKS instructions:

Connect EXP1 from Mainbaord with EXP1 of the display.
Connect EXP2 from Mainbaord with EXP2 of the display.
I did that and nothing worked

Caution, there is a risk that the display will be damaged if the connection is made with correctly flat ribbon cables (as delivered).

Makerbase has twisted the pinout in relation to the mounting direction of both EXP sockets. To use the display you need to do these steps:

1. Attach the supplied ribbon cables to the display in such a way that the cables come out downwards. This helps with later installation in a housing.
2. Cut off both plugs at the free end of the ribbon cable (leading to the mainboard).
3. Two new plugs have to be mounted the other way around. This means that the color marking of the cables must not lie on the side with the triangle marking of the plug after installation. This is actually mismatched for normal use. However, it is necessary in this particular case to compensate for the error made by MKS. Of course these cables may not be used for other applications.
   

It sounds more complicated than it is. But you have to know about it.

Of course, the firmware has to be adapted for the display, too.

Greetings
AETEK

Samuel Pinches

Thanks for this. I am not sure if there is a consistent standard or not for the keying of the plug. I know some people have run into the same problem on other printers, but I can’t remember what model motherboard.

MKS actually make a nice compatible graphical lcd module (I prefer that over the 4-line char LCD) that works with this motherboard, and even has an SD card slot too. I imagine that one is plug and play.

http://s.click.aliexpress.com/e/cX23pbde

AETEK

Hello,
yes, there is a standard. Otherwise you would not know how to mount the plug to the ribbon cable. Therefore, the plug has the triangular mark. MKS did it right with the AUX-1 connector. The square pin corresponds to pin 1. If you look at the position of the slot in the AUX-1 socket, then you recognize it.
Compare that with the EXP connectors. It's the wrong way around there.
My display also has a loudspeaker, SD card and rotary encoder. I chose it because it needed less processing power. The text display needs max. 30ms. The graphic display up to 180ms to redraw. The text display puts less pressure on the MEGA2560. It also shows no less than the graphics display.

cheers