It’s time for some tinkering

Putting things together, solving a problem with an Arduino or trying to communicate with a new device. I do it all, but always forget to write anything down.

This blog is intended as a place for documenting the different projects I work on, partly as an extended memory, but also to help others in need of similar solutions.

To spice it up a little, I’ll try to report from related events – like Maker Faire this weekend – or comment on interesting projects by other people.

7 thoughts on “It’s time for some tinkering”

  1. Michael says:

    Thomas, I’m completely new to the world of electronics, I used to program Fanuc 6-axis arc welding robots and decided to learn raw electronics. Like many others, I decided to start with the Arduino system, which, while there are many resources, it’s all geared towards those whom already know just about everything already. I don’t even know what a capacitor, inductor, transistor or ADXL335 are or do.

    I was wondering if you could help me or provide me an accurate layout to get my LCD display to display actual text and not just initialize the backlighting. I have tried 14 diagrams and I either get the backlighting to come on or the LCD matrix comes on (but doesn’t display characters).

    I also don’t know what each of the pins on my Arduino Uno board mean (other than the 3.5v, 5v, and GRD). Any basic info and working diagrams are greatly appreciated.

    -Mike

  2. Hi Mike,

    Arduino is a great start into electronics, but if you are all new and don’t know the different component types and diagrams, learning the basics would be good and help you a lot down the road. There is a book called Make: Electronics (http://shop.oreilly.com/product/9780596153755.do) that tries to help you with that.

    When it comes to these basic character displays (those that use in http://www.hackmeister.dk/2010/08/4-lcd-displays-on-1-arduino/) it’s just a matter of hooking up wires to the right pins on the Arduino and then using a potentiometer (adjustable resistor) to set the contrast. If you don’t set the contrast it might be all working, but with the contrast so low or high that it looks like nothing is on the screen (if you can’t find a potentiometer, a 1.5 Kohm resistor between the contrast pin on the LCD and GND will also work in most cases). It’s all explained pretty good at http://arduino.cc/en/Tutorial/LiquidCrystal

    You could also look into maybe getting an Arduino starter kit with little exercises to go through. Maybe something like https://www.sparkfun.com/products/12060 (there is a little guide book included, also available for download on the product page).

    I hope it helps!

    /Thomas

  3. Michael says:

    Thomas,

    Thank you for the resources. I bought an Arduino starter kit that came with a booklet from Sunfounder but the layout in the book and the layout file on the disk were completely different and neither worked completely. I’ll check out those links and try to ask more accurate questions later on. Thank you for your very quick response.

    -Mike

  4. Michael says:

    Thomas,

    Using the resources you provided, I was able to complete the LCD screen, but it required several modifications. Below is a link to a PDF layout with details and a text file with the code. Let me know if you see any errors. I layed it out to be very user friendly towards someone else in my position.

    PDF Layout w/details:
    https://www.dropbox.com/s/yca56o83altjsuv/Power%20Duration%20LCD%20Timer_bb.pdf?dl=0

    Text file with code for Arduino Uno:
    https://www.dropbox.com/s/3x9csebi8bz3mou/Power%20Duration%20LCD%20Timer.txt?dl=0

    Thank you,

    -Mike

  5. Hi Mike,

    It seems correct!

    If you get text on the screen you have connected it correctly and have the right code. Besides the potentiometer, you don’t need any support components when using a display like this. In other cases you might need a few small capacitors here and there to eliminate noise, but if you are just experimenting, don’t spend time on that, unless performance is unstable.

    Good luck!

    /Thomas

  6. Michael says:

    Thomas,

    What would cause “noise”? Better yet, what is noise? Is it fluctuation in a current? Any articles that could give me better insight? I see that many motherboards on different devices have multiple small capacitors and have wondered the purpose of that.

    Thanks,

    -Mike

  7. Well, noise could be many things, but it’s usually something like cross talk from one wire carrying a lot of current, that ends up polluting the signal in another wire close by. It’s all electromagnetism, and one common source is AC mains, usually in the 50-60 Hz, but it can also be part of your own circuit. Maybe a motor controller, that switches on and off very fast to keep a specific speed, that signal could disturb a sensor, or maybe force the power rail to fluctuate a bit, and if it goes to low, the microcontroller might reset. That’s the sort of problems you might see.

    When we talk high end computers, the electronics operate at very high speeds, and very small tolerances. If not properly constructed, it won’t work at all, og maybe stop working one day where it’s a bit warmer or when it’s raining or what not.

    For most DIY electronics with small microcontrollers, you can skip a bit of these extra components, but when speed goes up and voltage goes down, it gets more and more important, and if you move on from breadboard prototype to custom PCB, you usually tart looking into these things.

    I don’t have a link to a good tutorial or similar, but take a look at the designs from different Open Source Hardware companies like Sparkfun, Adafruit and Seeed Studio, just to name a few, and you will start to learn some best practices.

    /Thomas

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