Introduction: Oh, My! OLED PICAXE Digital Clock - IR Set!
A non-military display codebase is here: http://www.picaxeforum.co.uk/entry.php?63-AXE133Y-Evolution-with-20X2-for-Display-12-hour-Clock-amp-Temperature
Digital Clocks have been a fascination for many electronic enthusiasts for over 50 years. My first homemade digital clock used a clock chip from Radio Shack (Archer brand) and some old fluorescent digital displays (tubes!) intended as replacement parts for calculators. I built many of these in my college days because they made really nice gifts and were relatively inexpensive; my wife purchased arts-and-craft wooden boxes and painted and decorated them for the display case. One still survives at her mother's house after 40 years and still works. Of course, I'm still the only one that can set it after a power failure.
Technology has made digital clocks with "atomic" auto-setting widely available in both digital and analog forms, often for prices under $10. With prices so cheap, it is difficult to justify building a home-brew clock these days. But something interesting has become available in the past 12 months at an affordable price and it is again fun to build your own digital clock and you can program and customize the software in many ways: for example, perhaps a Valentine present that says "I Love You" instead of "Current Time:" on every hour! Endless possibilities. The newly affordable technology is OLED and it glows! No backlight required... the pixels produce their own light when energized. These new displays are fantastic and affordable at under $23 U.S. dollars which includes a very powerful PICAXE microcontroller, uC.
The project being presented here requires more than novice skill to assemble, at least average soldering skills will be required and you will need a fine-point soldering iron - so put away that brazing torch and get out the pencil soldering iron and small diameter rosin core solder. You will also need a PC (Windows/Linux) and a homemade serial download cable: DB9 to stereo 3mm jack. The programming software is free and is downloadable from a reputable site in the UK. All will be detailed in the following sections.
Step 1: Step 1 - Parts Are Parts
2) The next item that must be ordered unless you are just fortunate to have a few in your parts box, is the InfraRed, IR, detector. There are many of these available to the electronic hobbyist and I purchased mine from here:
3) The last critical item for ordering is the AXE133Y OLED display with the PICAXE 18M2 uC chip. These are available from:
Full BOM with approximate price as of 12/26/2011:
** The PICAXE firmware recognizes "Sony" compatible signaling. I am using a "dollar store" universal remote that has the "Sony" mode selected per the in-box instructions.
Step 2: Assemble, Test, Program, Enjoy...
Line 1: Serial OLED
Reprogram the AXE133Y with the clock software code:
Download the code from this page to your PC and then open the code in the programming editor by using the "File Open" option. Once the code has been loaded into the programming editor, you can transfer the code to the PICAXE and update the program (sometimes called "burning the [code into the] chip...")
Things to remember:
- The clock display (AXE133Y), the quartz clock module, and the IR module all share the same ground (GND) connection.
- Wires should be kept very short to minimize the effects of AC hum which may be introduced into the IR and Clock lines. An induced electric signal can create havoc with this circuit. You may find that placing a 22K resistor between 0V and C0 on the piggyback board will provide a small load and assist in minimizing interference on the clock line. The best way to avoid interference is to assemble the working circuit into a metal box.
- Setting the clock involves inputting 6 digits, one at a time. The input format is HH:MM:SS and the clock will automatically start with the sixth digit pressed on the remote. If you are attempting to "hack" the time display to a radio or other accurate source, you may need to allow 1/2 to 1 second for the internal software to resync with the correct display after pressing the value for the last second. That is, press the last second input a weebit before the accurate time source indicates that time. Practice makes perfect.
Enjoy you newly built OLED clock with InfraRed, IR, remote settings.
Keep a watch on this link for additional improvements and new software announcements:
Step 3: Add Thermometer
I have updated the code to allow for a thermometer to be displayed. Required is a 10K quarter-watt 1% resistor and a 10K "NTC" thermistor. One leg of the resistor goes to +5, the other leg of the resistor and one leg of the thermistor are connected together and this goes to pin "C.2" on the display piggyback board, and the other leg of the thermistor goes to ground.
The entire upgrade is here: http://www.picaxeforum.co.uk/entry.php?41-IR-set-18M2-Clock-Thermometer along with the necessary code. Free registration is required before you may download, but this is the official PICAXE product site, so it is both secure and most informative... a great resource.