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Topic: Aquarium Reef Controller, stage 1, the LCD shield, (Read 41 times) previous topic - next topic


Apr 14, 2010, 12:28 am Last Edit: Apr 14, 2010, 12:36 am by Harlequin Reason: 1
yeah My current shield uses none of the standard digital pins, but slots into all of the digital PWM pins.

I assume the input doesnt need PWM.

shield and arduino mega top down,

looking at the mega with the USB port to the left, analog pins facing you.

from left to right the pins that are used are as follows:-


Anaglog IN pins 0-5

looking at the mega with the Digital PWM and Communication ports to you with the USB port to the right.

pins right to left pins used are:

PWM 13 - 8

PWM 7-0

could i simply use jumper leads to rewire all the current pins that are in the PWM to digital pins,

then rewrite the:
LiquidCrystal lcd(8, 9, 4, 5, 6, 7)

to what ever digital pins i used.

see what i mean?

now that im looking at it IF LiquidCrystal lcd(8, 9, 4, 5, 6, 7) variables are used to define the LCD, and 2 pins stick in the AREF and GND....what does pin 0-3 and 13-10?  i need to sit and read the schematic again.. but not now tomorrow when i can think straight lol


I imagine the LCD is communicating with the arduino over i2c then. I think your idea would work, but looking at the schematic should clear it up.

They do sell a pin doubler at liquid ware which would allow the shield to go over the arduino but duplicate the pins so you can actually use them. It's about $18. It might be worth considering depending on how you want to do the wiring, but it would be the same as if you just ran jumpers out to a breadboard.

I got a i2c board to interface with the LCD and communicate with my arduino today. it only requires 4 wires go to the arduino, but there isn't an existing library to work with the controller yet. I'm waiting for the lcd and keypad controller to come from web4robot.com, which has a working library, but it's already been 2 weeks with no response from them.


Apr 14, 2010, 04:26 pm Last Edit: Apr 14, 2010, 11:51 pm by Harlequin Reason: 1
Quotes "I imagine the LCD is communicating with the arduino over i2c then."

i'll take your word for it :P, after a quick google, i ended up alittle confused and just took it at face value, my lcd is i2C haha, if anyone has a laymans explaination id appriciate it.

I had my physics/techie friend come round for lunch today and showed him my progress with the arduino which he was pretty impressed, he's pretty good at reading schematics etc and he's coming over for dinner this sunday so im sure i can pick his brains a bit more about it then, i plan to move it to some protoboards and hopefully connect up some LED's to mimic my LED rig. ( i need to steal his/my electronics bits box, most of the DIY projects i've done have been at his house so i just left all my electronics at his, resitors, led's, proto boards wire, solder etc...)

Put a bid on some DS18B20 chips (x5) earlier today so i'll probably win them, if not i'll jsut bid on the next lot until i get some. £7.60 intotal but the postage is a bit of a b***h and can take anywhere between 10-20 days, hopefully sooner. I looked around to see if there were any stockpiles in the UK i could order from but they were hellishly exspensive compaired to these ones from HK. I dont want them that badly to warent the cost.

Going to order my RTC clock in a moment as well, hopefully this will come sooner as theres a few suppliers in the uk that sell them for around £12.  just trying to think if i want anything else while i order.

Think thats about it.... wondering if i can justify buying a 20x4 plus a key...  ;D

out of interest how easy is it to make a RTC module by scrach?
I can buy the Chip and crystal for 1/3rd of the price of a prefabricated module?

I'd have to get a cell battery and holder as well but that would be no more then a few Pounds?

I wonder how difficult would it be to program/build? or should i just go ahead and buy a pre made one and save myself some trouble?

anyone got a decent DIY tutorial etc?

edit: RTC schematics from sparkfun

as long as i get these bits and bobs and have a pre programmed DS1307 chip i should be on a winner no? just seems alittle expensive for something that looks like it could be done with a few hours DIY'ing...

second edit: I dont even need a pre programmed chip... i could set the variables myself, the chip does the auto calibrate/configure for me... thats the whole point.

third edit some hours later: Won the DS18B20 chips, so i have 5 of those on the way sometime this side of 20 days the wait begins  :-?


You can definitely build your own RTC, I just wanted one that was on a PCB for compact size.
I ordered mine from Futurlec, but they take a very long time to ship as well. web4robot contacted me and told me my i2c controller for my LCD will ship Monday, so at least there's progress.

I don't know if I had asked this yet, but do you have an plans for enclosing the controller? I'm thinking about using black acrylic and building my own box, but I don't have the best tools for cutting. I checked out a lot of project boxes locally, but didn't find anything appropriately sized.


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