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How's your chinese?
:D

Trying to send by message. I can't attach a PDF here.

EDIT: Nope. Don't see any way to attach in PM either.

I suspected my voltmeter gave a faulty reading, so I connected 2 ammeters in series (removed my yellow power LED at the bottom to give a more true reading).

9746

14.5mA! That's just crazy low....

First test with 4 dual-encoders with LCD driven from 16F18877.

Barely 25mA to drive entire circuit, including backlight.

9745


I still have to do more contrast & backlight tests on these,...

Yup, they are just awesome! I'm so happy I went with this supplier. :) If you ever want to order a large batch, let me know and I'll give you the rep's contact info over at...

Comparison between LCDs from AliExpress (first batch), and LCDs from Alibaba. The viewing angle on the Alibaba units is really good.

Note that the contrast and backlight are not tuned for the...

Agreed, white-on-blue has a lot of interest amongst hobbyists. Here's a video alongside a black-on-white. Notice the better viewing angle on B-on-W.

https://youtu.be/eFnoAjXVUdo


(still have...

I'm waiting on red text on black and white text on black. I expect them to be about 130-150mA backlight.

This batch of white on blue have terrible viewing angle. I bet they are designed to be on...

That's the thing. These are from AliExpress so I can do initial testing.

I'm waiting for a manufacturer to send an order of samples. It's the same product, but the version might be different,...

LCD model 2004A V1.3

White text on blue background

Contrast:

- 2N2222A NPN with 1K on base
- 0.20mA with PWM @ 1953 frequency (recommended)
- 0.46mA with PWM @ 1953 frequency (maximum with...

Short answer, yes, probably. I only got it working on contrast so far.

The top left pot controls contrast.

https://i.imgur.com/e64aaIb.jpeg


I used a 2N2222A transistor with 100R resistor...

Ooops, just to clarify, that 24V is the title of that schematic.

I will be using 12V wall adapters, maybe even 9V to minimize heat (if I can find a good deal).

My circuits are exclusively 5V.
...

Well, that's disappointing. I looked only at Mouser, the IC alone is over $6 and most of the discrete components are not available. I don't know enough if I can replace them with components.
...

A lot of those converter circuits look like they were done in some cave. This one looks surprisingly well done:

https://www.aliexpress.com/item/1005001629723875.html


The 5V pro variety comes...

I'm currently using these buck converters to drop from 12V from wall adapter down to 5V:

https://www.amazon.ca/gp/product/B0B5GQTS64/


These go for $2 each and they are only rated at max 3A...

(post removed, because I can't tell the difference between a circuit that provides power to PIC, and a circuit that provides power while relying on PWM from a PIC)
:D

That is my biggest concern with this plan.


My design now has 3 enclosures, with power being fed into the center unit. I'm now thinking of using 3 separate voltage regulators; one per unit.
...

From what I've seen so far, backlights on LCDs (often over 100mA) still consume a lot of current compared to the logic circuit (usually in single mA). I'd like to improve that.

9698

Since LED...