Serial LCD Assembler Code

Regular Guy · Joined: 04 Jun 2017 Posts: 110

While we are getting ready to solder our parallel LCD.

We do have the assembler program for that.

We do have a serial LCD with the wiring harness ready to go.

Do not have any code for this though.

They are both 16x2 green ones.

Any comments on doing this?

Thanks! Smile

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temtronic · Posted: Fri Oct 30, 2020 5:23 pm

You'll need the datasheet for both of the LCD modules.
Parallel units typically can be run in either 8 bit or 4 bit mode BUT that depends on WHO made the unit so that datasheet is critical.
It will tell you required VDD ( usually 5 Volts but could be 3 volts). Also the pinout. Some( most ?) require the 'contrast' pin , usually pin 2, to be a fraction of a volt( .4-.6_ though , that again varies depending on the make/model of the LCD module.
Most people use the 4bit mode if available as it frees up 1 I/O pin. There is a basic driver and here in the code library there should be a 'flex_LCD' driver. It allows you to use nearly any I/O pins for the connections to the display. I've used it for years on several projects, never had any problems.

A 'serial' LCD will have it's own 'command set' to configure and send data to the LCD screen. Most configure to 9600 baud, 8 bit as a default, and TTL mode 'RS232'. Again, you'll NEED the datasheet to properly setup/run the module.

Jay

Regular Guy · Joined: 04 Jun 2017 Posts: 110

Thanks Jay

Well. Think the thing to do is stick with the parallel LCD.

Been having a little problem soldering single row pin headers.

25 watt soldering iron.

Not getting good flow onto the pin.

Been fluxing the heck out of the work area.

Might have been making a mistake cleaning tip with copper scrubber AFTER tinning the tip.

Been told to clean tip. Tin it. Then leave it alone.

So it transfers heat to the pin.

Gets things hotter.
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temtronic · Posted: Fri Oct 30, 2020 6:22 pm

Wipe the tip of the iron htrough a wet (very damp) sponge after a few solderings. It'll remove the flux buildup.
Also use fine (small diameter, .050 ??) solder. I like 63/37.

After 50 or 60,000 connections, you'll get real good at it !
Jay

Regular Guy · Joined: 04 Jun 2017 Posts: 110

Thanks

Well. We we do get the hang of it.

There are stacks of boards here that need pin headers soldered on.

The latest wrinkle is a couple 'stick' type boards with really small solder pads. Ouch!

Question: We found a 16x2 LCD parallel. It has 14 pin double row connector on the cable.

Was that a standard pinout in that era?

We have two different brand boards with 14 pin double row connectors.

Be nice if the LCD would work with one especially.
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temtronic · Posted: Sat Oct 31, 2020 6:32 am

You can use Google to try to find datasheets for the LCD modules. Use whatever 'markings' on the PCB as the Google 'search keywords'.

Regular Guy · Joined: 04 Jun 2017 Posts: 110

Thanks Jay! Smile

The parallel LCD soldering pins on it is getting thrown on the slow boat list.

Turns out we have 4 or 5 ready made dev boards with LCD's already on them.

The push for an LCD is for debugging.

Without that all you know really is the program does not work.

That is getting a little old.

Question: Anybody know where to get sheets of black foam for storing PIC's reasonably?

Have to organize a whole bunch of them.

Thanks!
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temtronic · Posted: Sat Oct 31, 2020 2:27 pm

usually I just store in the 'tubes' they come in. Those tubes are antistatic and I write on them the PIC type.
If you know of a local manufacturer or a school, they may have empty tubes they will donate to you.

Jay

newguy · Joined: 24 Jun 2004 Posts: 1908

https://www.digikey.ca/en/products/filter/accessories/603?s=N4IgjCBcpgHALFUBjKAzAhgGwM4FMAaEAeygG0QBmeWAdgAYBWEAXSIAcAXKEAZU4BOASwB2AcxABfImACcsWUhCpImXIRLkQ9Vh26Q%2Bg0ROkgAtACYlKwQFcNpSBWZsQXHlNNWnIPDgAmAARoxBgAtqySQA

If the link doesn't show up, just search Digi-Key for "ESD foam". Lots of options.

Regular Guy · Joined: 04 Jun 2017 Posts: 110

Thanks Newguy

'ESD foam'

That is where we were floundering. Using wrong name for it to search.

Ebay has tons of it.

Okay. We are getting ready to dive back in to PIC assembler lessons.

Going to breadboard the circuit from our book.

16F84A with 32khz crystal and two 68 caps.

Will keep everybody posted.
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PCM programmer · Joined: 06 Sep 2003 Posts: 21708

The best product for storing DIP package IC's is:

Conductive Crosslink Foam
CCI-LD 32
1/4 inch thick
Pin insertion grade
5 -10^3 ohms cms
Density 2.0 (lbs/sq. ft.)
Mfr: Conductive Containers Inc.

http://www.techni-tool.com/265ST3624
$28.35 USD for a 24"x36" sheet
(A lifetime supply)

-------------------------------
Pillowstat box
http://www.techni-tool.com/265ST7035
The pillowstat box does not come with the
pin insertion grade foam. It comes with
a soft foam for surface mount chips.
You lay the SMT chips on top of the foam.
I replaced that foam with the CCI-LD 32 foam.

temtronic · Posted: Sun Nov 01, 2020 5:29 am

Hopefully the new stuff lasts longer than the stuff I bought in the mid '70s. It's finally 'crumbled' into bits and NO sun got to in in cases, in the basement.....

Found some voltage controlled opamps, used in a synth I once made.....

Regular Guy · Joined: 04 Jun 2017 Posts: 110

Thank you for the tips about black foam.

Found out a little tidbit.

Remember the 16F1459 CCS stick we were fooling with?

Apparently the 16F1459 and the PIC18F14K50/PIC18F13K50 are related.

CCS seems to like those.

I should have caught the 50 on the end. Usually means USB.

They are both 20 pin chips.

We will work our way up to those someday.
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Regular Guy · Joined: 04 Jun 2017 Posts: 110

Didn't quite pull it together on that last post.

PIC18F14K50 is PIC CCS uses on the E3 mini too.

Apparently the big attraction is they are minimum chips with USB.

Plus they are newer big memory chips for C.

There!
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temtronic · Posted: Sun Nov 01, 2020 2:22 pm

While it has hardware USB, I assume you have to add the 'driver', which obviously takes up codespace,also the USB conector..
I know when the 4450 came out about 1/3 of codespace was needed for USB...
I've since settled on the 18F46K22 with external TTLUSB module. While the TTLUSB module costs $2 CDN,it costs me at least $1 for the parts, and of course 2 PCB revisions...so really only $1 for USB capability AND NO codespace needed AND they WORK !
BTW a 14k50 is about $3.50 and the 46K22 is $4.50 here in Canada. For an extra $1, I get a LOT more speed, memory,peripherals and pins.