Lcd problem

hi. Last time i posted thread about my lcd problem which was not working after i connected power. Some guys suggested me to put contrast VR as i didnt put one because i didnt have that. Now i got one from ebay and i connected VR. At first it didnot show any respons. I thought it might damaged. But when i saw deeply there was blury boxes. I connected 4AA SIZE Battery. I thought these must be used. So i put new 4 batterys and adjust contrast. And then it was clearly showing that boxes. I just used the +v , 0v and contrast pin. Then i puted the other pins to get a proper output. I need to mention that i am using axe28x2 pinsC on Lcd. My project board is axe020. I puted the manual 3 Lcd (direct) commands by copy paste for my project. Now i dont know whats the mistake i made. Can anyone tell me please what i have to do? I use my mobile to post thread. So i cant attach all the ditails. Also i thing i dont understand that the datasheet says it needs 4.5 v. But when i put 3 AA battery. It still blank. Do need to put separate power for lcd?
( I AM GIVING THE LCD DATASHEET AND OTHER WEBSITE ADDRESS BELOW WHICH I FOLLOWED FOR PINOUT TO CONNECT THE CIRTAIN LCD)

http://www.picaxeforum.co.uk/archive/index.php/t-14760.html

Am not very good in English. Thanks for your patience.


http://elinux.org/RPi_Tutorial_EGHS:Alpha-Numeric_Display
 

MPep

Senior Member
Hi Shah,

If you are connecting to the "Output" pins, please be aware that they are connected to the ULN2803 chip. This is a Darlington open collector driver.
Download the datasheet for the AXE020. Look at page 2.

You need to connect between the PICAXE and the ULN2803 driver. Remove the ULN2803.
Both AXE020 and LCD board can be powered from the same 4.5V or 5V supply.
 

inglewoodpete

Senior Member
It's good news that the LCD is working! As I mentioned in my post on your other thread: patience and persistence.

4 x AA cells gives 6.0 to 6.5 volts, which is too high for both the LCD and the PICAXE. Voltage that high can damage them. As MPep says, use 3 x AA or a 5v regulated power supply.

The AXE020 and the CHI030 boards make it difficult to drive an LCD because they have a ULN2803 darlington buffer included on the board. Once again, as MPep says, unplug the ULN2803. If you are using solid conductor wire (just one thickish strand inside the insulation) you can poke the bare wire end into the ULN2803 socket's pin holes 1 to 8 to connect to the PICAXE's output pins (port B).
 
i allready removed darlington ic.

Thanks guys for answering me. I thought my thread was too long. Nobody will read it. I was waiting though. And then i did not get any replay so i tried once again to make my LCD work. But i couldnt. So i chuked into bin. And i ordered axe133 online. Anyway i learned about the ULNxxxx darlington ic before from Wastus. He told me about this in another thread. So i take off that before i connect Lcd. Also i was trying to fit the Lcd on pinsC, not on pins B. So it does not matter Uln is there or not. Thanks for your replay anyway.
 
about my new axe133 and i2c.

As i now going to use axe133 can you tell me please that will my 3AA bettery of axe020 be enough for that? or i have to use saperate power for it? As i let you know on my pevious thread that i tried with same power supply but The Lcd was still showing nothing. When i used seperate 4 AA bettery it showed boxes on screen. That means it needs separate 6v power supply. Another thing is i dont understand i2c bus at all. What is this in short. And what does it do in project. How can i connect my axe133 with axe020. Is there any role of i2c in this metter? Please help me. Thanks
 

nick12ab

Senior Member
As i now going to use axe133 can you tell me please that will my 3AA bettery of axe020 be enough for that? or i have to use saperate power for it? As i let you know on my pevious thread that i tried with same power supply but The Lcd was still showing nothing. When i used seperate 4 AA bettery it showed boxes on screen. That means it needs separate 6v power supply. Another thing is i dont understand i2c bus at all. What is this in short. And what does it do in project. How can i connect my axe133 with axe020. Is there any role of i2c in this metter? Please help me. Thanks
Please put new lines between each question, and don't ask so many at once!

3 AA batteries should be enough for a normal LCD module as long as the batteries haven't been used much. They are inadequate for extended temperature LCD modules.

4 AA batteries in series should not be used because the voltage produced is above the 5.5V recommended maximum so operation may be unreliable. 4 AA batteries are good if you use 4.5V for the logic (the Vss pin on each IC etc. should be connected between the 3rd and 4th cells) and -1.5V for the LCD driving voltage only.

lcd power.png
 
about i2c

Hi. I dont understand i2c bus at all. What is this in short. And what does it do in project. How can i connect my axe133 with axe020. Is there any role of i2c in this metter? Please help me. Thanks
 

nick12ab

Senior Member

hippy

Technical Support
Staff member
The AXE133 connects to the AXE020 using an asynchronous serial interface. This is an interface which will use a single digital output signal from the AXE020. You control that signal ( and the AXE133 ) from the AXE020 using SEROUT commands.

I2C is not required for doing this and I2C is not supported by the AXE133.
 

westaust55

Moderator
Hi. I dont understand i2c bus at all. What is this in short. And what does it do in project. How can i connect my axe133 with axe020. Is there any role of i2c in this metter? Please help me. Thanks
Where has the reference/need for i2c come from that makes you ask the question?
Neither of the web pages you give a link to at post 1 makes reference to i2c.

Is this in reference to something other than the LCD display for your project?
 
saperate power for axe133?

Thanks guys. Do i need to provide seperate power supply for axe133,like only negetive terminal will connect with axe020? Or i can use same power for both? I know that is a silly question for you guys. But for me its important. Because i think one power suply wont be enough for both. Thanks
 

westaust55

Moderator
Do i need to provide seperate power supply for axe133,like only negetive terminal will connect with axe020? Or i can use same power for both?
Presuming that your power is by three AA cells:

From a typical battery datasheet/spec for Energiser brand AA 1.5 V battery cells:
• Voltage: 1.5V
• Capacity 2850 mAh (Rated capacity at 25 mA continuous drain)
• High capacity designed for high drain application, like digital camera, camera, MP3 player, CD player, walkman.
• Shelf life: 7 years.

Look at the sheet: http://www.batteryspace.com/prod-specs/GEV-E91.pdf
From there the curves show that at 100 mA current draw the cells will last about 20 hours.

You really need to learn to search for data and to understand how to find some answers for yourself.


Is there an answer forthcoming to the question I raised at post 11 above? :confused:
Answering the questions put to you helps us to understand what you are doing so we the forum members can better help YOU.
 
didnt understand question@westaust

On your 11 post- i read lilbit about i2c and i never used 2 modules at once. So i dont know how to connect each other so thought it must be something about i2c.
My project is about showing the temp, massage, info etc. On lcd display of a remot controlled and voice controlled robot.
 
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