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Blog [Pi IoT] Alarm Clock #16: Wiring
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  • Author Author: fvan
  • Date Created: 15 Aug 2016 1:06 PM Date Created
  • Views 2254 views
  • Likes 4 likes
  • Comments 7 comments
  • fvan_piiot
  • piiot
  • wiring
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[Pi IoT] Alarm Clock #16: Wiring

fvan
fvan
15 Aug 2016

  • Proto Board
  • Colour Coding
  • PWR & ACT LEDs
  • Testing

 

With the enclosure finished, the next step is to wire everything together, as so far, most components have either been used individually or were connected using a breadboard: a more permanent solution is required.

 

Proto Board

 

Because there are different components requiring the same pins (5V, GND, I2C), a prototyping HAT was used to provide multiple connections. The board was cut in such a way that one row of 90° male headers pins could be soldered on to make connections. On the bottom side, adjacent pins were connected, creating different groups, each associated with a certain GPIO pin.

 

The required connections are:

 

7-Segment display8x8 Matrix displayLED ButtonI2S Audio Amplifier
  • +5V
  • GND
  • GPIO 2 (I2C SDA)
  • GPIO 3 (I2C SCL)
  • +5V
  • GND
  • GPIO 2 (I2C SDA)
  • GPIO 3 (I2C SCL)
  • +5V
  • GND
  • GPIO 6
  • +5V
  • GND
  • GPIO 18 (I2S BCK)
  • GPIO 19 (I2S LRCK)
  • GPIO 21 (I2S DOUT)

 

imageimageimage

 

I used some leftover LED leads I cut off to make the connections on the proto board image

 

Colour Coding

 

To facilitate the identification of wires and possible troubleshooting, colour coded wires were used.

 

In the wiring below, the following colours were used:

  • GREEN: I2C SDA
  • YELLOW: I2C SCL
  • RED: +5V
  • BLACK: GND
  • PURPLE: button
  • WHITE/GREY/BROWN: I2S Audio

 

imageimageimage

 

To keep things removable, female Dupont wires were used. Since these are off the shelf wires, they are a bit too long, but there is enough space inside the enclosure to fit everything.

 

PWR & ACT LEDs

 

A thing to pay attention to with this semi transparent enclosure, are the red and green glows created by the Pi's activity and power LEDs. In the dark, they manage to shine through the white acrylic. There is a method to disable these LEDs in software, which is the preferred option, but it doesn't seem to work (yet?) for the power LED on the Pi 3: https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=149126

 

Turning off the activity LED works though, and can be done as follows:

 

pi@piclock:~ $ sudo nano /boot/config.txt

# Disable the ACT LED
dtparam=act_led_trigger=none
dtparam=act_led_activelow=off

 

As a workaround, until a software solution is available for the power LED, I used a little piece of tape to mask the LED in a non-permanent way. For a permanent solution, a dab of nail polish could be used.

A single piece of tape wasn't enough to stop the light from shining through (those things are bright!), so I ended up adding four layers of tape to cover the LED!

imageimage

The light can no longer shine through, and the other components don't have any power/activity LEDs either. The only light shining is now the white light from the 7-segment display, the LED matrix and the button image

 

Testing

 

To test the wiring, I ran the different scripts controlling the various components: everything worked as expected. In the pictures below, I'm testing different weather icons: sun and rain. It's hard to take decent pictures due to the brightness (more blurred on the pictures than it actually is), but looks great in real life, slightly diffused by the acrylic.

imageimage

 

Wiring: complete!

 


image

 


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Top Comments

  • DAB
    DAB over 9 years ago +1
    Nice update. I am assuming you wanted the numbers to be a little diffuse. I have developing cateracts, so everything looks a little fuzzy to me. DAB
  • mcb1
    mcb1 over 9 years ago +1
    Not sure I know why the photo should appear more blurrry ... Now it's all together I can see it is a very useful and attractive bedside project. Last night we had someone talking about the very displays…
  • fvan
    fvan over 9 years ago in reply to mcb1 +1
    I'll be introducing another component I discovered only recently, for the second unit. Let's see if you still resist then
  • mcb1
    mcb1 over 9 years ago in reply to fvan

    Why slowly ?

    You're an aquired taste ...

    ... unless you open those special unmarked beers.   image

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  • fvan
    fvan over 9 years ago in reply to vish

    Why slowly ? image Just kidding, really appreciate the kind words, thank you!

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  • vish
    vish over 9 years ago

    Nice work - both technically and artistically. image

    I'm slowly becoming fan of your aesthetic sense image

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  • fvan
    fvan over 9 years ago in reply to mcb1

    I'll be introducing another component I discovered only recently, for the second unit. Let's see if you still resist then image

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  • mcb1
    mcb1 over 9 years ago

    Not sure I know why the photo should appear more blurrry ...

     

    Now it's all together I can see it is a very useful and attractive bedside project.

     

    Last night we had someone talking about the very displays you used.

    Glad I'd done some homework, and NO ....  I resisted that shopping temptation. image

     

    Mark

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