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Topic: Motorola C140 LCD Display (Read 4137 times) previous topic - next topic


Hi. This is my first post on the forum :)

Today I openned my old Motorola C140 cellphone.
Then I got this idea, I'm trying to control the phone LCD screen.

I googled for motorola C140 and found some information about the LCD pins.
I soldered some wires, connected to my arduino +5v and the display turned on. yay \o/

Ok, now I'm trying to communicate with the LCD. I think (because of the "pin" names) it uses I²C, which I never used.
The pin names (according with some material I found) are:


I connected SDA to my arduino's SDA and SCL to SCL.
VDD to +5v and VSS to GND (on the arduino).
I tryed to send random data to the LCD (hoping random bits to appear on the screen), but nothing happend :(

I searched a bit more, and discovered that VLCD is the LCD supply, so I connected +5v to it.
By doing this, the LCD turned off (also my arduino). (maybe short circuit?).
I also found that SA0 is the bit 0 of the I²C address (to use 8 bits instead of 7? don't know.), but I don't know what do I do with that.

So, my question is: Can anyone help me with this I²C stuff? Where do I put the SA0 pin? How do I properly connect this VLCD? I also don't know if there is a default instruction set for LCD's (like, to send instructions to it).
Also, I'm not using any component (like pull up resistors). I don't know if that's very important.

One more thing, I don't know if helps, but the LCD is a "toppoly TD014THEA3".


Just a little update: I tryied to put the "pull up resistors". Nothing changed.
I also discovered that the VLCD should go to GND. That's odd to me, but whatever, nothing changed.

Searching a bit more I found this:
"Address Inputs (SA[0:2])
These input signals are used to set the physical address of the EEPROMs on the I2C bus.
By hardwiring these pins to Vss or Vdd through the module edge connector, up to eight
unique addresses can be achieved."

Trying to solder the pin, I screwed my other solders. So, for now, I give up. Maybe tomorrow I try again... Those tiny pins are terrible.
Acctually, if there was a way to use the "plastic conductor" in the LCD, it would be much better :(


you should definitely have taken some measurements with the lcd still on the phone before messing with it. i have strong doubts that the lcd uses a 5 volt supply. most cell displays go from less or equal to 3.3 volts. also, alot of these lcd's have an initialization sequence before you can get them to do anything. some quick googling shows that the datasheet for this display is not easily found. i would hold of on messing with it until you found some more information.


Pictures we need to see pictures of this Hack please, i have recently Hacked into the Motorola F3 and came to know it is some Alphnumeric Strip LCD.
"Real Men can Accomplish  Anything"

- skype : nishants5  
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