HowTo: pxlBlck – Build your own pxlBlck_CassetteLamp

MP3 players, smartphones and USB sticks with 128GB and more memory are now part of everyday life. Storing and transporting music has therefore never been easier.

About 30 years ago it looked different. The “USB stick of the 80s / 90s” was the cassette.

Of course, I still have a lot of them flying around and still don’t have the heart to dispose them. On the other hand, it also breaks my nerd heart that these tapes rot in some box in the basement.

That’s why I was looking for a way to combine “the old” with something practical and thus get the cassettes out of your boxes.

The result is the pxlBlck_CassetteLamp. A lamp that uses semi-transparent cassettes as a lampshade and, thanks to WiFi connection, can also be used as a source of information for events in the SmartHome in addition to the lamp function.

What you need and have to do to build your own pxlBlck_CassetteLamp is described in the following article.


Safety instructions

I know the following hints are always a bit annoying and seem unnecessary. But unfortunately, many people who knew it "better" from carelessness lost their eyes, fingers or other things or hurt themselves. In comparison, a loss of data is almost not worth mentioning, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Even the coolest project is worth no injury or other annoyance. https://www.nerdiy.de/en/sicherheitshinweise/

Affiliate links / advertising links

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Requirements

For the construction you have to master SMD soldering tasks. The following articles provide tips on how to do this.

Required tools:

Required material:

In the following list you will find all the parts you need to assemble.


Collect the parts you need

So that you can start building your pxlBlck_CassetteLamp, you should first find all the parts you need.

For the construction of the pxlBlck_CassetteLamp you need (among others) the following parts.

  • 8x semi-transparent audio cassettes
  • 1x Wemos D1 Mini 32x WS2812 or SK9612 LEDs in 120LEDs / m length
  • 3x cables approx. 10cm long
  • 3D printed base
  • 3D printed mounting frame
  • 3D printed lid (optional)
  • 4x M3x10 cylinder head screw
  • 8x M3 nut
  • 4x M3x16 cylinder head screw

Another view of the required parts.

For this example structure I printed the base out of cork or wood filament. Of course, you can also use any other 3D printable material here.

This photo also shows the parts that you can use to control the lamp using the APDS-9960 gesture sensor. The light can be switched on and off using gestures, dimmed lighter and darker and the color can be adjusted.

As an alternative, you can also control the lamp using two rotary encoders.

So the lamp can be adjusted with a pen. This is a small “homage” to the combination of pen and cassette that used to help you roll up unwound cassette tapes. 🙂

Another view of the required parts.

Another view of the required parts.

The STL files for printing on your 3D printer can be found in the repository for the pxlBlck_RingClock under the following link.


Screw on the mounting frame

First you should start with the preparation of the mounting frame.

You will need the following parts for this.

  • 4x M3x10 cylinder head screw
  • 8x M3 nut
  • 3D printed base
  • 3D printed mounting frame

At the beginning you should place the mounting frame on the 3D printed base as shown.

Then position it in line with the holes in the 3D printed base …

… and screw it with the provided M3x10 cylinder head screws.

Repeat this with all four corners.

On the underside you should screw the four screws with the prepared M3 nuts.

Bottom view of the screwed M3 nuts.


Glue on the LED strips

In the following step the LED strips are mounted on the base.

For this you need the prepared base including the mounted mounting frame and the four LED strips, each with eight WS2812 or SK9612 LEDs.

Close-up view of the required LED strips.

Now glue the first LED strip in the middle on the inside of the mounting frame.

Make sure that the small arrows on the LED strip always point in the same direction, and also with the following LED strips.

Now mount the next LED strip in the middle on the inside of the mounting frame.

Again, make sure that the arrows point in the same direction. In this case, all arrows point counterclockwise.

Now glue the third …

… and fourth LED strip on the base as before.

As soon as you have glued all of the LED strips on, this should be roughly …

… look like this.


Solder the LED connection cable

After you have installed the LED strips, you now have to solder them together and solder a connection cable. This is not always easy with this type of LED strip due to the small size of the soldering pad. Therefore, you should take your time for this section. You can also find tips for using the soldering iron in the following articles.

An approx. 10 cm long three-core cable is very suitable as a connection cable.

Remove the insulation of the ends of the cables for this …

… approx. 5mm and …

… tin them with some solder.

Now look for the soldering pad on the LED strip which is marked with a minus sign and is relatively close to the through hole in the 3D printed base.

Then tin it with some solder. This makes it easier to solder the connection cable later.

The tinned solder pad can be seen here on the lower LED strip.

Now you can also tin one of the soldering pads that are marked with a plus sign with some solder.

After you have prepared the soldering pads, you can start soldering the leads. To do this, first solder the red line to the soldering pad marked with a plus sign as shown.

Close-up of the soldered line.

Now repeat this step with the connection line for the soldering pad marked with a minus sign.

Close-up of the soldered line.

Another view.

After you have soldered the supply lines, the line for the data input can now also be soldered to the LED strip.

To do this, tin-coat the upper left contact of the LED (visible in the picture) with some additional tin-solder.

In this example, the line is soldered directly to the LED because it is a little easier to solder compared to the very small soldering pad at the beginning of the LED strip.

Now you can solder the connection line for forwarding the LED data to the LED strip.

Close-up view of the soldered line.

It is important here that there is no short circuit with the neighboring contacts and soldering pads when soldering.

You should also make sure that the arrows on the LED strip “point away” from the connection line.

Soldered, you can now lead the connection line through the hole in the base into the base.

Another view.


Solder the LED strips together

Soldering the LED strips together is also a bit tricky. Here, too, you should work carefully and give yourself a little more time. Make sure that you do not create any short circuits with neighboring contacts and measure again if necessary. 🙂

For this you should have already prepared the base as shown.

In this step, the contacts marked with a minus are first connected to one another.

To do this, solder the soldering pads of the adjacent LED strips marked with a minus sign to one another as shown.

Repeat this for the other LED strips until …

… you end up with the soldering pads of all the LED strips …

… soldered together.

Now repeat this again with the soldering pads marked with a plus sign.

To do this, solder the soldering pads shown using …

… a short piece of wire.

Then the connections of your LED strips should look as shown.

Another view.

In the last step you now have to establish the data connection of the individual LED strips.

As before, you should connect the contacts on the LED strips to one another. This time, however, the middle contacts.

Repeat this again for all three corners until …

… your structure looks something like the one shown.

Another view.

Another view.


Connect the ESP8266 or Wemos D1 Mini

After the construction of the LED strip has been completed, you can connect the microcontroller to the LED strip.

For this you need a breakout board based on the ESP8266-ESP12E.

I recommend using the “Wemos D1 Mini” here.

First glue the Wemos D1 MIni with some hot glue …

… in the bulge provided for this purpose …

… into.

Then prepare the contacts of the Wemos D1 Mini with some solder.

To do this, tin-plate the following contacts with some solder.

  • G
  • 5V
  • D6

Now you can solder the first connection line to the Wemos D1 Min.

Solder the black wire to contact “G” of the Wemos D1 Mini.

This black line should be the line that you previously connected to the contact marked with a minus on the LED strip.

Another view.

Now repeat this with the red line and the “5V” contact of the “Wemos D1 Mini”.

The red line should be the line that you previously soldered to the contact of the LED strip marked with a plus.

Ultimately, you should solder the signal / data line of the LED strip to the “D6” contact of the Wemos D1 Mini.


Option 1: Prepare the APDS-9960 gesture sensor

There are basically two options for controlling the colors and brightness of your pxlBlck_CassetteLamp. The first – described here – works with the help of the “APDS-9960” gesture sensor. With the help of this sensor, the lamp can be switched on and off by gesture movements over the lamp and its color and brightness can also be changed. The gesture sensor works quite reliably depending on the ambient brightness. Sometimes, however, it does not recognize every gesture correctly.

Further information on connecting the APDS-9960 gesture sensor to ESPeasy can be found in the following article.

The other control option is implemented using two rotary encoders. You can find information on this in the section Option 2: Prepare the rotary encoder holder

To set up the control using the gesture sensor, you first need the parts shown.

Another view of the required parts.

In order to prepare the connection line, you should now strip the ends approx. 5mm and tin them with some solder.

Now position the sensor as shown …

… and solder it to the previously prepared lines.

If possible, you should …

… keep the assignment of the line colors to the contacts.

Close-up of the APDS-9960 sensor with soldered leads.

For the correct positioning of the sensor, you should now install it in the bracket shown.

To do this, insert the M3 nuts into the recesses shown.

Another view.

Another view of the two M3 nuts used.

Then you can pull the connection lines of the sensor through the cable gland as shown.

Another view.

The sensor can then be attached using the mounting holes and the M3x16 cylinder head screws and therefore can be …

… screwed to the bracket.

Another view of the screwed sensor.

Another view of the screwed sensor.

Another view of the screwed sensor.

Another view of the screwed sensor.

Another view of the screwed sensor.

Another view of the screwed sensor.

Another view of the screwed sensor.


Option 1: Mount the APDS-9960 gesture sensor

After mounting the APDS-9960 gesture sensor on the bracket, it is now time to mount and screw the bracket to the base of the lamp.

For this you need the components shown.

Splits the lines as shown …

… remove the insulation of the lines approx. 5mm …

… and tin them with some solder.

Then guide the line through the middle hole in the …

… base of the lamp.

Then you can use the …

… M3 nuts and M3x16 cylinder head screws …

… to screw it together.

To do this, insert the M3x16 cylinder head screws through the base from below.

Did you screw the sensor with both screws …

… your structure should look something like this.

Another view.

Another view.

Another view.

Now you have to connect the connection lines of the sensor with the Wemos D1 Mini.

Solder the red wire of the sensor to the contact “3V3” of the Wemos D1 Mini.

You should also connect the black wire to contact “G” of the Wemos D1 Mini.

Make sure that the red wire is connected to the “VCC” contact and the black wire to the “GND” contact of the sensor.

The last two lines of the sensor are responsible for the I2C communication with the Wemos D1 Mini.

Solder the blue wire (sensor SCL) to contact “D1” and the green wire (sensor SDA) to contact “D2” of the Wemos D1 Mini.


Attach the cassettes to the mounting frame

After mounting the gesture sensor, you can now mount the cassettes on the lamp.

For this you need the prepared base of the lamp and eight semi-transparent cassettes.

You can of course also use tapes with less transparency. Combine here as you like it best.

Further view of the required components.

In the following steps, the cassettes are attached to the mounting frame with some hot glue.

Make sure that the cassettes are staggered onto the frame.

First apply some hot glue to the left and …

… right flank of the first side of the mounting frame.

View of the mounting frame including (still) liquid hot glue.

Now the first cassette is glued to the mounting frame flush with the left flank.

The cassette is on the right side …

… slightly beyond the mounting frame.

View of the left side of the cassette. This should be flush with the mounting frame.

Now you can mount the next cassette on the next side of the mounting frame.

Top view of the first two glued cassettes.

You can now glue the following cassettes to each other and to the mounting frame in the same way.

Another view of the glued cassettes.

Another view of the glued cassettes.

Another view of the glued cassettes.

Another view of the glued cassettes.

Another view of the glued cassettes.

Now also glue the “next level” of the cassettes to the mounting frame in the manner shown above.

Another view.

Another view.

Another view.

Another view.


Option 2: Prepare the rotary encoder holder

The second option for controlling the pxlBlck_CassetteLamp consists of two rotary encoders, which are mounted in such a way that they can be controlled from the outside using a pen. In this way, the brightness and color of the lamp can be adjusted.

For this you need the components shown on the left.

  • 2x rotary encoder
  • 2x M3 threaded insert
  • 2x M3x16 countersunk head screw
  • 8x cables approx. 10cm long in different colors
  • 2x cable approx. 3cm long
  • 1x 3D printed bracket
  • 2x 3D printed encoder attachment
  • 1x bracket clamp
  • approx. 20cm shrink tubing suitable for the cable diameter

Close-up view of some of the required components.

Close-up view of the lines required.

Close-up view of the lines required.

Close-up view of some of the required components.

Circuit diagram for an overview. Here it is shown how the rotary encoder is connected to the Wemos D1 Mini. Further information on the connection of rotary encoders can also be found in the article ESPEasy – Connect rotary encoder to the ESP8266 and evaluate it

Now solder the lines shown with the first rotary encoder as shown.

Another view of the soldered lines.

Repeat this with the other lines also with the second rotary encoder.

Another view of the prepared rotary encoder.

Another view of the prepared rotary encoder.

Another view of the prepared rotary encoder.