Arduino 101 meetup prep – day 1 – LCD display

4May2009 – old stuff that may still be useful

Thought I should figure out a few things about this Duemilanove board before the Friday meetup.  To that end I rummaged through my lab to collect a bucket of parts that might illustrate some fundamental “peripherals” people might like to see connected to an Arduino.  Collected LEDs, switches, pots, an LDR, a VU gauge, a hall sensor, a servo, an L293 h-bridge, and an LCD from an old printer console, shown here:


But before you get to this, you need to…

Reverse out the connections from the LCD daughterboard to the main board that offers a connector pinout for the LCD + the switches and LED which make this an “all-in-one” sort of peripheral

It’s nice to see the Hitachi HD44780 controller on salvaged parts.  So well documented and widely supported.  Notably by the Arduino example code.

This isn’t the most beautiful hookup to the Duemilanove, but it’ll do

And once you get all the wires soldered to the correct pads late at night…

You need to remember that ribbon cable has a twist in it so that’s really D4 to D7 instead of the other way around.  But it did lead to interesting display traffic for a bit.  And then finally with the LCD, 3 switches and 1 LED wired up…

I modified and ran the sample code in Library-LiquidCrystal/SerialDisplay provided with the Arduino Software .

A few observations:

  1. Salvaged PC hookup wires come in handy.
  2. Remember to enable the Arduino’s internal pull-ups on the input lines here.
  3. Reflashing the board when running SerialDisplay requires that you shut down HyperTerminal or whatever term you’re using to send data to the LCD, at least under Win.
  4. You really should use your labbook instead of scrap paper when reversing any board, ’cause you’ll probably want to refer to this stuff later.

Hope to make a few more bits to share before Friday.


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