axe033 Help please

S

Svejk

Senior Member
Recently I've bought the Picaxe033 lcd display. I've assembled as per instructions but the only thing that I've got out of lcd are black blocks.

I've tried to adjust the contrast pot, no results.

I've checked the connections, soldering, all good:

pins 1, 5, 7-10 to 0v
pin 2 to 5v
pin 3 to pot
pin 4 (RS) to 8 (PIC16...)
pin 6 (E) to 9 (PIC16...)
pin 11 (DB4) to 6 (Pic...)
pin 12 (DB5) to 12 (pic...)
pin 13 (DB6) to 13 (pic..)
pin 14 (DB7) to 15 (pic..)

or at least that's what my multimeter says.

I've read first 6 pages of search results about axe033 but still no answer.


Any ideas? The last 3 days were very frustrating :mad:
 
S

Svejk

Senior Member
I'm using it serial.

The code is:

Code: 
init: 
  pause 500

main:
  serout 7, N2400, ("Hello")
I've shorted the CLK pin but nothing appears on LCD.

The Picaxe chip is 18x.

Thanks.
 
E

eclectic

Moderator
First, remove the clock jumper.

Then try this simple program:

Code: 
init: 
serout 0, n2400,(254,1) ; clear display

pause 50 ‘ wait for display to initialise

main: 
serout 0,N2400,(254,128) ‘ move to start of first line

serout 0,N2400,("Hello") ‘ output text


serout 0,N2400,(254,192) ‘ move to start of second line

serout 0,N2400,("World") ‘ output text
I've used output 0, but your output pin can be changed.

e.
 
S

Svejk

Senior Member
Thanks Ozzie, I've allready read that thread and checked the soldering over and over because the simptoms are similar. I've even soldered the both sides of lcd PCB just to double check.

I've checked the connections with my multimeter. I know what a dry solder is.

Anyway, to eliminate the possibility of a dry joint, I've just checked again.

I don't think the soldering is the problem.
 
K

kevrus

New Member
A basic check that I carried out when having problems playing with an LCD for the first time was to connect a resistor in series with an LED and connect it to the pin that you are using for serial out. It should flicker if the 18x is sending data.
It obviously wont check the data but it will suggest that something is bieng outputted...might be worth a try
 
I

inglewoodpete

Senior Member
"Black Blocks" is often a sign that something is wrong with the contrast control. With most LCDs, the contrast is controlled by a 10k trimpot. I don't have an AXE033 but can see in the AXE033 documentation that there is a 10k trimpot on the support board.

Does turning the trimpot between its extremes make any difference to the black blobs?

If not, do you have a multimeter to measure the voltage on the trimpot's wiper as it is turned? This should vary between 0 and 5v, or the 033's supply voltage
 
D

Dippy

Moderator
As IP says to check.

Plus:
Is your power supply good? What is it? Have you checked it?
Have you checked voltages at chip and LCD +V?
What happens if you pull the chip out and power LCD up?
 
S

Svejk

Senior Member
Does turning the trimpot between its extremes make any difference to the black blobs?

If not, do you have a multimeter to measure the voltage on the trimpot's wiper as it is turned? This should vary between 0 and 5v, or the 033's supply voltage
Click to expand...
Yes, turning it makes boxes fade/disapear. voltage varries with turning.


Plus:
Is your power supply good? What is it? Have you checked it?
Have you checked voltages at chip and LCD +V?
What happens if you pull the chip out and power LCD up?
Click to expand...
Power supply is 3xAA batteries, currently at 4.67V. Yes, Checked them. As stated before I had no choice but to rule out a soldering/wiring problem.

[pause 3 minutes here]

ok, 4.57V at batteries with load
3.88V at chip.
4.38V at lcd
[multimeter used: ANCO AM-8209]

Pulled out chip, still black boxes.


On the other hand, out of desperation, I've desoldered (painful operation) the lcd from axe033 and I've soldered another lcd and still black boxes.

Pulling the chip gives the same results, guess it can be the PIC16...? Googled searches came with the answer of soldering or initialization failure.
 
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W

westaust55

Moderator
Svejk said:
I'm using it serial.

The code is:

Code: 
init: 
  pause 500

main:
  serout 7, N2400, ("Hello")
I've shorted the CLK pin but nothing appears on LCD.

The Picaxe chip is 18x.

Thanks.
Click to expand...
With the CLK pins shorted, the AXE033 ignores both serial and i2c input.
It should show any pre defined message on the top line and the time/date on the bottom line - but only with a RTC fitted.

If you are not getting to this point then the problem is with the AXE033 so lets forget the PICAXE for the moment and look at the AXE033 alone.

Do you have a DS1307 RTC fitted?
What do you get with the CLK pins shorted and varying the contrast pot?


BUT . . .

you say that you are still getting black boxes on the LCD even with the PIC chip on the AXE033 interface board removed. Yet the contrast pot does vary the boxes from black to faded out.

Is every character location filled with a black box, or only some - if some, which ones?


A complete filled in box at a character position is the equivalent of the character value $7F being sent via the serial line. But again with the PIC chip removed you still have black boxes so its not coming from the serial interface.

EDIT:
a comment made by hippy to a past thread:
"A single row of black blocks is usually symptomatic of an uninitialised LCD; powered up but not receiving or responding to what's being sent."
 
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S

Svejk

Senior Member
With the CLK pins shorted, the AXE033 ignores both serial and i2c input.
Click to expand...
My bad, I didn't mention correctly. So that should be read:

As per manual, when you power up the axe033 and short out the CLK pin the lcd should dislplay the currrent date/time (no picaxe connected)​

When trying the serial connection I've opened the CLK pin.

Do you have a DS1307 RTC fitted?
What do you get with the CLK pins shorted and varying the contrast pot?
Click to expand...
I'm using the DS1307, clk pin shorted, results are still black boxes.

I'll try to initialise the lcd directly from 18X if i'll get a bit of time today.

There is any way/metod to check the PIC16...?
 
S

Svejk

Senior Member
Just an update: I've initialised the lcd directly from picaxe and works ok. I've used Hippy's brililant code and instructions. That means the problem lies in the AXE033 pcb.

Thank you for your support.



PS: Hippy, BTW

Most LCD modules will have a single 14-way connector, and 16-way if backlit, and are normally numbered as shown, with Pin 1 being 0V (or "Vdd").
Click to expand...
isn't that the other way around?
 
S

Steve_Reeves

New Member
help needed, same problem

Hi Svejk,
I have exactly the same problems that you experience, would you kindly post the outcome that eventually fixed the problem.
Many thanks
 
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