Sainsmart 12864 LCD backlight and SD speed questions

Hi everyone,

Do you know if there is a way to force the backlight on on the 12864 LCD?

It only turns on 5 seconds when I push the button, and it's not enough for me.


My other question is about the USB file transfer to the SD card. It takes me 5 minutes for a 2Mb file.

Do you have faster transfer rates?

my clone 12864 LCD has a variable resistor on the backfront to set how long it stays on

re speed...

repraps are serial sevices... the speed you set in firmware is the speed of uploading to the sd card.
so for most its 250000 baud or 115200 baud.

This is why most recomend copying it to the SD on the computer then moving it to the printer

Now in saying that there are some controlers that are not limited to the baud rate
The ones based on AT90USB1286 have virtual UARTS, what this means is that it ignores the baud rate you enter, and uploads as fast as it can, up to usb speeds (limited by controller cpu power) eg the printrboard and Teensylu.

I believe that the newer 32 bit boards, smoothie board and azteeg x5, also use this sort of trick and get full usb (2?) speeds (not confirmed)

Edited 4 time(s). Last edit at 05/08/2014 06:37AM by Dust.

Thanks for the answer Dust,

I tried 25000 bauds but it won't connect, I have to stay on 115200. I will take out the SD for transfers.

I also checked the resistor, there are two.


I can reach the first one on the white board, but the second one is behind on the green board and everything is soldered. Wich one is it?

Quote
Dust
I believe that the newer 32 bit boards, smoothie board and azteeg x5, also use this sort of trick and get full usb (2?) speeds (not confirmed)

The Azteeg X5 with Smoothie firmware actually presents the regular interface as a USB tty device, and also presents the on-board micro-SD card as a USB thumb drive at the same time through the same USB cable. It acts as it's own SD card adapter, and programs like Cura can save directly to the Azteeg X5 when they finish slicing.....

The jumper on the back will turn it on permanently iirc.

Thanks MiggyMan!! It works!!

On the white board, on the back, lower middle silver variable resistor labled con adj is the contrust adjustment
On the white board on the front side, above the light button is a second variable resistor, Time adjust. you want that one.

The jumper on the back selects the backlight mode. Either timed, or on full time.

Try 230400 baud, works for alot of people, twice as fast as your doing now.

Edited 3 time(s). Last edit at 05/08/2014 06:38AM by Dust.

I'll try it. Thank.
There is already a four hour batch running.

On paper the maxium throughput of 115200 baud equates to 14Kb/s (well, kibi's now)

2500000 to 30.5Kb/s

So

2Mb @ 115200 will take 146 aprox seconds
2Mb @ 250000 will take 67 aprox seconds

USB 1.0 (most card readers, even internal ones, are usb) pushes 1.5Mbit/s (1500000), which equates to 183Kb/s

2Mb @ 1.5Mbit/s will take aprox 11 seconds

In short, transfer it to the card with a computer

Hello. I purchased a 12864 RepRapDiscount Full Graphic Smart Controller and am having a few issues with it.

I was able to get the unit to turn on, but I'm experiencing the following problems:

1) The contrast adjust doesn't work at all
2) The selection knob, when turned isn't very precise - however I found a video that describes how to clear that up which I plan on trying out later
3) Most distressing to me is that the display starts to dim after a few minutes until it's barely readable.

I've been searching for more information regarding using this larger display with Marlin firmware and am having difficulty finding the right answers. I've read some comments where you can keep the backlight display on by switching a jumper and enabling the contrast adjustment by adding a resistor to pins 1 & 2 on the board. Also, as I mentioned above, there's a video that will help me with the selector knob.

So, the main issue right now is the display fading away to barely readable after a few minutes.

I am using an Arduino Mega 2560 with Ramps 1.4 board. Marlin 1.0.6 is installed

The board I have is a red one and there are no jumpers on the back to enable the backlight to stay on all the time.
The long set of pins on the daughter board weren't straight enough to mate the board with my Ramps 1.4 board without effort
I just finished removing them and re-soldered them straight and I also removed the LCD and re-soldered all the pins to the LCD as well

I would really appreciate any advice regarding my issues. Many thanks.

Quote
MiggyMan
The jumper on the back will turn it on permanently iirc.

quick question (although i'm a bit late to the game) do you know which pin the jumper connects to gnd or +5... so i can put it in the menu?