which is the best picaxe to use for connecting to an lcd

Flenser

Senior Member
Peter,

I was updating your earlier thread before I saw this.

You can use any PICAXE that has at least 6 outputs to drive a character LCD so as inglewoodpete said the minimum out of the current chips will be a 14M2.
 

AllyCat

Senior Member
Hi,

ANY PICaxe (including 08M2 and 18M) can (be made to) drive SOME LCDs, but until you tell us which "LCD Display" it is, we can't possibly say which PICaxe is "Best". Conversely, some LCDs can't be driven adequately by ANY PICaxe. And how do you define "Best" : Fastest, Simplest/Smallest Hardware, Easiest to use, Lowest Cost, etc..?

Cheers, Alan.
 

Flenser

Senior Member
Peter,

Alan is correct. Inglewoodpete and I have both assumed that you were asking about this type of character LCD below, most commonly with the 1 row x 16 pin connection in the picture below but they can also have the same 16 pins in a 2 row x 8 pin arrangement.

1 row x 16 pins enables you to plug it into a solderless breadboard for testing.

This 2 rows x 16 characters is the one most often seen but you can find them on ebay from 1 row x 8 characters up to 4 rows x 40 characters
24379

If you are asking about this type of character LCD then our comments stand.
If you are asking about some other type of LCD then our comments probably do not apply.
 

peter howarth

New Member
Hi,

ANY PICaxe (including 08M2 and 18M) can (be made to) drive SOME LCDs, but until you tell us which "LCD Display" it is, we can't possibly say which PICaxe is "Best". Conversely, some LCDs can't be driven adequately by ANY PICaxe. And how do you define "Best" : Fastest, Simplest/Smallest Hardware, Easiest to use, Lowest Cost, etc..?

Cheers, Alan.
Thankyou, I just want to connect a fairly common type of lcd 16 x 2 character, the hitachi 44780 i think is the common regular type, (available over here in australia,) to a picaxe device, be it the 14m, the 20m or the 28m, but prefferably a picaxe device that can run the lcd ok and with a few input pins spare to allow different messages from different inputs/events ..The type of lcd that I can end up using isnt dictated by cost or size, even if its similar to what appears to be a common type like what flenser has sent thru a photo of..

I have followed instructions written by revolution education in their manuals, and apart from it doesnt work, it leaves a lot to be desired..When I say it doesnt work, the program code listing doesnt even get to the downloading stage before there is a hiccup ie syntax errors, and thats program listing written by revolution education themselves, so what hope has a beginner got?
 

AllyCat

Senior Member
Hi,

"It doesn't work" really isn't very helpful. :( And Which Editor , PE5 or PE6 ?

But first, Which PICaxe are you trying to program? It's usually best to put a #PICAXE 18M2 (or as appropriate) at the top of your program (so that the Editor and We will know what you're trying to do). AFAIK an 18M will have a Microchip (4-digit) number on its top, whilst the more recent M2 chips will carry the appropriate xxM2 or xxM2+ characters.

If you haven't bought the LCD yet, you should consider the OLED type which as far as Rev Ed are concerned have "replaced" LCDs, which may be why the AXE133 is no longer available, replaced by the Yellow OLED version (AXE133Y). They are more expensive than cheap LCDs from China, and we will help you drive those as well, but you should also consider the Pros and Cons of the basic "Parallel" type against those with an "I2C Backback".

Cheers, Alan.
 

Flenser

Senior Member
Peter

"the program code listing doesn't even get to the downloading stage before there is a hiccup ie syntax errors"

You must post the code you are trying to download so that we can inspect it to identify what is going wrong and/or attempt to download exactly the same program to a chip using PE to see the errors for ourselves. When including code in a post pls use the "Insert </> Code" option.

Most importantly, do not despair. Keep in mind that there are a _lot_ of people who have been using PE and the PICAXE chips and successfully downloading programs over many years so I'm very certain that people in the forum will be able to identify what is going wrong for you.

My suggestion is that we first solve what is preventing you downloading a program.
Once we are past that hurdle we can certainly point to to a program and circuit to use with one of the 14m, 20M and/or 28X2 chips that you have on hand.
 
Last edited:

lbenson

Senior Member
For hippy's 14M 4-bit 16x2 LCD code and wiring, check one post above this:

 

AllyCat

Senior Member
Hi,

+1 , just to endorse what a beautiful example of Program Code hippy wrote 12 years ago! And it still compiles without errors in PE5 or PE6 provided that the correct PICaxe type is set. ;)

The "4-bit mode" is probably the "Best" method of driving these displays; less connections than the full byte-wide data bus, so more pins available for other functions and you don't have to struggle to find a completely "unused" port (of 8 bits). Also, it can be converted to drive the I2C backpack type of display by changing just a few lines in the subroutine. So a 14M{2} could be ideal for your requirements.

Alternatively, the AXE133 (type of) display is somewhat easier to drive. Those seem to be mainly out of stock even over here at the moment, but take a look at its dedicated AXE132 ASCII backpack which includes a PICaxe 18M2, that you could attach to one of the low-cost LCD displays (and I think includes the important "contrast" pot). That alone has a moderately favourable shipping breakpoint (before insurance kicks in), so it looks as if it would be delivered via Airmail for a fraction over AU$20 (and Rev Ed appear to be "open" for a few more days before Christmas). Or $17.69 from Wiltronics, but I think they add more for shipping?

Cheers, Alan.
 

peter howarth

New Member
Peter

"the program code listing doesn't even get to the downloading stage before there is a hiccup ie syntax errors"

You must post the code you are trying to download so that we can inspect it to identify what is going wrong and/or attempt to download exactly the same program to a chip using PE to see the errors for ourselves. When including code in a post pls use the "Insert </> Code" option.

Most importantly, do not despair. Keep in mind that there are a _lot_ of people who have been using PE and the PICAXE chips and successfully downloading programs over many years so I'm very certain that people in the forum will be able to identify what is going wrong for you.

My suggestion is that we first solve what is preventing you downloading a program.
Once we are past that hurdle we can certainly point to to a program and circuit to use with one of the 14m, 20M and/or 28X2 chips that you have on hand.
Thankyou Flenser, whereabouts are you emailing from in the world, also how do
 

peter howarth

New Member
Thankyou Flenser, whereabouts are you emailing from in the world, also how do i send any photos to the picaxe forum, so at to better explain the problems I am having with the program code listings , even before the downloading stage to the picaxe device? I am using the picaxe pe6 platform version 6.0.8.6, or should I be using a later version that I dont even know about, yet

I used to be able to send photos of screen shots to picaxe support, but picaxe support no longer operates, thanks to covid 19..

Does anyone in australia sell the OLED display , if not , then I am back to square one..
 

Flenser

Senior Member
Peter,

Instead of emailing this stuff just to me it's a better idea to put the code and any pictures into a post using these two options. This will enable everyone in the forum to see them and help you if I can't see what is wrong.
24385

When you paste your code using this option it will appear in your post properly formatted in a "Code" section like this which makes it easy to everyone to read:
Code:
; main program loop, runs at 16MHz

main:

    serin RX,baud,b1            ; wait for the next byte

    ; NB keep character mode test as first item in this list to optimise speed
    if b1 < 253 then
        let pinsB = b1         ; output the data
        pulsout enable,1      ; pulse the enable pin to send data.
        goto main            ; quickly loop back to top
 

Flenser

Senior Member
Peter,

This link from AlleyCat in post #11 is to the AXE132Y kit from Wiltronics in WA: AXE132Y: Serial OLED/ LCD Driver Board Only . This is the same as the AXE133 kit just without the LCD. i.e. you use your own 2 line x 16 character LCD that has the 1 row x 16 pin connector.

If you'd prefer to buy the full AXE133 kit Wiltronics don't sell that but they do sell the AXE133Y kit OLED Display Module Serial Only Input. The only difference between the AXE134Y and the AXE133 is that the AXE134Y comes with an OLED display instead of the LCD display.
 

peter howarth

New Member
Peter,

Instead of emailing this stuff just to me it's a better idea to put the code and any pictures into a post using these two options. This will enable everyone in the forum to see them and help you if I can't see what is wrong.
View attachment 24385

When you paste your code using this option it will appear in your post properly formatted in a "Code" section like this which makes it easy to everyone to read:
Code:
; main program loop, runs at 16MHz

main:

    serin RX,baud,b1            ; wait for the next byte

    ; NB keep character mode test as first item in this list to optimise speed
    if b1 < 253 then
        let pinsB = b1         ; output the data
        pulsout enable,1      ; pulse the enable pin to send data.
        goto main            ; quickly loop back to top
Sorry if I sound vague, but where do i find these 2 options, to be able to paste photos etc on the forum
 

Flenser

Senior Member
Peter,

This first screen shot is me typing this reply before I've clicked "Post reply" and across the top of my reply pane are a set of icons:
24386

You use this "Insert image" icon for pictures:
24387

And this "Insert" menu to get the "</> Code" menu option for program code:
24388
 
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