How to Run a Statically Driven LCD display
How to Run a Statically Driven LCD display
(OP)
Hi all,
I have attached a 2 page spec sheet on a an LCD display component that I am trying to get to work. I am conforming to its 3V operating voltage by supplying it 3V to the pins. The display only flickers for a second and sometimes not at all. The component itself works and have cross checked it with others. My question is, how are LCD display screens wired up to work?
I notice that on the spec sheet there is a line on page 2 that mentions "driving method: static". A colleague mentions this as the culprit. The LCD needs to be driven by a driver. Can someone tell me what components I need to make this thing work?
Regards,
I have attached a 2 page spec sheet on a an LCD display component that I am trying to get to work. I am conforming to its 3V operating voltage by supplying it 3V to the pins. The display only flickers for a second and sometimes not at all. The component itself works and have cross checked it with others. My question is, how are LCD display screens wired up to work?
I notice that on the spec sheet there is a line on page 2 that mentions "driving method: static". A colleague mentions this as the culprit. The LCD needs to be driven by a driver. Can someone tell me what components I need to make this thing work?
Regards,





RE: How to Run a Statically Driven LCD display
For example, I recently used a New Haven Display NHD-2.4-240320SF-CTXL#-FTN1 and they also sell the NHDev evaluation board to drive it and recommend an ILI9341 driver.
A lot of microcontrollers have built in LCD drivers (TI, Atmel, etc.) so you might look there too.
Z
RE: How to Run a Statically Driven LCD display
1. Apply a current-limited 3Vdc across pins 2 and 1, with the positive on the 2.
2. Slowly increase the current limit until the '-' sign appears. If nothing happens up to about 20mA, then stop, something isn't right.
3. If the '-' sign does appear, briefly increase current up to about 25mA to see if there's current limitation built in.
4. Do the same for pins 3 and 1, which should cause the first '1' to appear.
That should give you enough information to get the rest of it working.
The "static" bit most likely just means that it can be DC driven. Some LCDs require a high frequency supply to keep the cells operating. I don't think a 240x320 TFT driver (the ILI9341) is the way to go for a few 7-segment displays.
RE: How to Run a Statically Driven LCD display
Here's an example from Atmel...
http://www.atmel.com/Images/doc2569.pdf
As I recall, a sustained DC bias will eventually damage the display.
RE: How to Run a Statically Driven LCD display
Jim, thanks for the link. Could you possibly provide me a "step by step" guide in order to make it work? I really don't know where to start.
RE: How to Run a Statically Driven LCD display
RE: How to Run a Statically Driven LCD display
Each segment is driven with a square-wave signal as jimkirk described, with the backplane as the common of the square-wave signal. A segment (in positive-mode LCD type) that is in-phase with the backplane does not show, while a segment driven 180 degrees out of phase will show.
Your LCD seems to have several backplanes in the description. This may be so it can be more usuable for some non typical applications (like a processor with several ports emulating a LCD driver, and one pin of each port emulating the backplane??). Most drivers will have plenty of output drive pins but one backplane pin. In this case, just hook all the LCD backplane pins together to the one driver backplane pin.
RE: How to Run a Statically Driven LCD display
As a matter of interest is it possible to just use a shift register to drive the LCD screen without a drive?
I refer to the link below:
http://blog.hovertop.com/2012/07/driving-a-16x2-lc...
RE: How to Run a Statically Driven LCD display
RE: How to Run a Statically Driven LCD display
RE: How to Run a Statically Driven LCD display
There are also microcontrollers with built-in LCD drive capability where the timers/ports are setup to make this much simpler.
Another old hardware way used shift registers and XOR gates. Or was it NOR gates? can't recall exactly.