Introduction: Portable Electronics Station

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This is a small electronics workstation designed to be used while traveling, or for if you don't have enough space in your house for a full sized workstation. It has a built-in computer, oscilloscope, Arduino, and other features.

Materials:

Electronics materials:

Note: the USB keyboard is necessary for working on the Raspberry Pi originally, but will not be used in the completed station. If you already have a USB keyboard, you can use that instead of buying one, as it will not be used in the station permanently.

Box materials:

  • 0.75 x 2 x 22.75 inch strips of lumber (4x)

  • 0.75 x 2 x 17.75 inch strips of lumber (4x)

  • 17.75 x 24 0.25 inch sheets of Masonite (2x)

  • 1.25 x 3x 3 inch blocks of wood (4x)

  • Duct Tape

  • Superglue
  • Contact Cement
  • 22.75 x 17.125 0.25 sheet of masonite (1x)

Tools:

  • Dremel
  • Chisel
  • Fine-tipped marker
  • Coarse-Grit Sandpaper
  • Soldering Iron
  • Drill
  • Drill Bits

Step 1: Constructing the Box, Part One

Unfortunately, the box I used to make the workstation was already made, so I don't have any photos of the box during construction. However, I do have another box exactly it, so I figured out how that was made and included the instructions here.

Screw or nail two of the shorter strips of lumber on the ends of two of two of the longer strips ( main photo). Screw or tack one of the sheets of Masonite to the rectangular frame you just made ( top right photo). Repeat this process once. Set your two frames side by side, but not quite touching. Lay your hinges in place ( middle right photo). Trace the hinges on the frames, in the position where they will be set. Use a chisel to carve the wood inside the areas which you traced until the tops of the hinges are flush with the wood ( bottom right photo). Screw the hinges into the areas which you indented with the chisel.

Step 2: Constructing the Box, Part Two

Take the 22.75 x 17.125 inch sheet of Masonite and glue one of the 1.25 x 3 x 3 inch blocks of wood on each of its corners, as shown in the photo on the left. The side of the Masonite with the wood blocks on it will be the underside of the main panel. Drill a grid of ventilation holes on the side of one of the halves of the box, as shown in the photo on the left. Use a drill bit size of approximately 1/4 inch.

Step 3: Constructing the Box, Part Three

In this step you will be mounting the containers for the electronics components. I had a limited selection of container types, so the pictures included will not correspond directly to the instructions. The instructions should still work, and actually provide a more efficient use of the space than the system I have. Take the four storage containers and position them so that they all fit in the half of the box without the ventilation holes in it, and can be opened in the position you chose. Trace each of the containers onto the Masonite in the position you chose. Use sandpaper to rough the area inside the places you outlined and the bottoms of the containers. Cover the bottoms of the containers and the areas you roughed on the Masonite with contact cement. Wait for the contact cement to dry. Once all the contact cement is dry, press the contact cement-coated sides of the containers against their corresponding area of contact cement-coated Masonite. The containers can now be used for holding electronics components.

Step 4: Mounting the Touchscreen

Cut a rectangle of paper with dimensions 6.5 x 4.13 inches. Position the paper in the position of the touchscreen in the main photo. Trace around the photo with a fine-tipped marker. Use a Dremel with a rotary cutting head to cut along the lines you drew. Remove the rectangle of Masonite that you cut out. Make a small indentation in the bottom left area of the cutout for the ribbon cable, as shown in the top left photo. Turn the sheet of Masonite over and support the ends of it on two boxes. Carefully lay the touchscreen into the indentation, making certain that the circuit board extensions with the screw holes in them rest securely on the Masonite sheet. Mark where the screw holes on the circuit board meet with the Masonite. Drill small holes on the spots you marked, using progressively larger drill bits until the screws included with the touchscreen fit through the holes you drilled. Lay the touchscreen back into the indentation. Screw the touchscreen into place with the included screws. Connect the HDMI cable and the included USB cable to the screen, as shown in the bottom left photo. Make sure the backlight is in the on position, as shown in the bottom left photo.

Step 5: Installing NOOBS on an SD Card

It is necessary to download the NOOBS system onto a blank SD card. NOOBS stands for New Out Of Box Software. It is an easier way to install the Raspbian operating system into the Raspberry Pi. To find instructions, as well as the download, click here.

Step 6: Set Up the Raspberry Pi

Connect the HDMI and USB cables from the touchscreen to the Raspberry Pi. Plug the USB hub and USB soundcard into the Raspberry Pi. Insert the SD card into the SD card slot on the Raspberry Pi.

Step 7: Glue the USB Hub

First, select the place you want your USB hub to be glued. You will be gluing it to the underside of the main panel, the side with the Raspberry Pi on it. It should be a spot where it can be connected to the Raspberry Pi while the Raspberry Pi is connected to the touchscreen. Try to make sure that none of the cables are bent while the USB hub is in the position you chose. Outline the USB hub on the area where you want to glue it. Sand the area which you outlined with coarse-grit sandpaper. Sand the underside of the USB hub with the same sandpaper. Apply a layer of contact cement to both areas that you sanded, then let them dry. Once both areas have dried, firmly press the USB hub's coated side to the area that you marked out. Continue to press for a minute or so.

Step 8: Mounting the Breadboard

Clean the area above the touchscreen with a damp cloth, making sure it is free from dirt and dust. Carefully peel back the protective tape from the back of the breadboard, being careful not to remove the adhesive layer. Press the back of the breadboard against the area you just cleaned until it sticks tightly. Attach the breadboard power supply to the bread board, as shown in the main photo. Be sure that all the pins on the bottom of the power supply board line up with the power rails on the breadboard. Drill a small hole in the Masonite, in a position close to the barrel jack on the power supply. Plug the male barrel jack into the female barrel connector on the breadboard power supply. Unscrew the covering from the male barrel jack. Run the wires from the 9v battery clip through the hole you drilled in the Masonite, making sure that the clip is on the underside and the wires are on the top. Slide the barrel jack cover that you unscrewed over the wires. Solder the positive(red) wire from the clip to the inside pole of the barrel connector, and the negative(black) wire to the outside ring of the connector(bottom right photo).

Step 9: Mounting the Powerbank

Position your powerbank on the front of your box(main photo). Trace around the powerbank with a fine-tipped marker. Use a Dremel to cut out the wood inside the section that you outlined. Use the Dremel to make two indentations in the wood next to the hole you just cut, for the charging and output cables(top right photo). Plug the cable that was included with the powerbank into the charging side of the powerbank, and plug the cable with the switch on it into the output side of the powerbank. Slide the powerbank into the hole that you cut for it. The powerbank should fit securely, without twisting or bending the cables. If the powerbank fits properly, secure it in place with duct tape. Plug the micro USB end of the cable going out of the powerbank into the micro USB power connector on the Raspberry Pi. Trace the switch in the cable going out of the powerbank onto the Masonite, near the touchscreen. Cut this area out using the Dremel. Plush the switch through the hole until the top of the switch is flush with the Masonite(bottom left photo). Glue the switch in place with Superglue. Make sure that the switch is in the off position.

Step 10: Charging

Cut a 5/8 x 3/8 inch hole. This will be where you plug in the charging cable for the station. Position the USB extender on the underside of the Masonite sheet so that you can see the entire USB port through the hole(main photo). Mark where the screws will go through the Masonite to mount the USB extender in this position. Drill 1/8 inch holes in all the positions marked. Screw the extender in place using the included screws. Plug the USB female to female adapter into the USB cable going into the powerbank. Plug the USB extender into the other side of the USB adapter. Plug the USB male to USB male cable into the USB phone charger. To charge the station, plug the cellphone charger into the USB extender with the USB male to male cable. You may want to use a marker to write "charging" or some other indication near the USB extender to differentiate between it and the data USB ports. Note: the powerbank used for this Instructable does not support pass-through charging, meaning that you cannot charge the station and use the computer at the same time.

Step 11: Mounting the Arduino

Unfortunately, I was unable to find a kit of screws specifically for mounting an Arduino, so I have included a link to a kit with some bolts, nuts, and standoffs. First, position your Arduino directly above the Breadboard(left photo). Use your marker to mark where you will drill holes for the screws to mount the Arduino. Use a 2mm drill bit to drill holes in all the positions you marked. If the bolts included in the kit won't go through the holes then, use a 2.5mm drill bit to enlarge the holes. Position your Arduino so that the screw holes on the Arduino line up with the screw holes you drilled in the Masonite. Run the screws through the screw holes on the Arduino and the holes you drilled in the Masonite. Screw a bolt onto the end of each of the screws and tighten (right photo).

Step 12: Arduino Power and Data

The Raspberry Pi doesn't have enough power to power the Arduino and the touchscreen at the same time, so the Arduino has a nine-volt power supply to power it, and a USB cable for data transfer. Drill a small hole in the Masonite, in a position close to the barrel jack on the Arduino. Plug the male barrel jack into the female barrel connector on the Arduino. Unscrew the covering from the male barrel jack. Run the wires from the 9v battery clip through the hole you drilled in the Masonite, making sure that the clip is on the underside and the wires are on the top. Slide the barrel jack cover that you unscrewed over the wires. Solder the positive(red) wire from the clip to the inside pole of the barrel connector, and the negative(black) wire to the outside ring of the connector. Screw the cover for the barrel jack back onto the barrel jack. Drill a 1/4 inch hole in the Masonite, approximately two and a half inches from the USB connector on the Arduino. Cut the USB A to USB B cable in half, then run the half with the USB B connector on it through the hole you just drilled(left photo). Strip an inch of the outer insulation off of both halves of the cord. Remove half an inch of insulation from each of the smaller wires in both halves of the cable. Twist the exposed sections of the like-colored wires from both halves together to create a splice. Wrap the splice with electrical tape to insulate it. Repeat this process with all of the wires in the cable. Wrap the spliced section of the cable with more electrical tape until it is thoroughly covered(middle photo). Plug the cable into the USB hub(right photo).

Step 13: Installing Matchbox Keyboard

Matchbox Keyboard is a virtual keyboard that can be used to type on the Raspberry Pi without needing an external USB keyboard. First, plug the USB keyboard into the Raspberry Pi. Then turn the Raspberry Pi on. To turn the Raspberry Pi on, press the button on the powerbank and set the power switch to on. A NOOBS startup screen should come up. Select Raspbian in the list of options the startup screen gives you. Click the Install icon. Once Raspbian has downloaded, and the Raspbian main screen has come up

To install Matchbox Keyboard, go to the Raspbian terminal and type these commands.

sudo apt-get install matchbox-keyboard
sudo reboot

Once the Raspberry Pi has rebooted, go to Menu > Accessories and Matchbox Keyboard should be there. Unplug the USB keyboard from the Raspberry Pi and turn the Raspberry Pi off. To turn the Raspberry Pi off, go to Menu > Shutdown > Power off. When the green indicator light on the Raspberry Pi stops flashing, you can set the power switch to off.

Step 14: Making the Oscilloscope

First, turn on the powerbank. Once the Raspberry Pi has booted up, go to Menu > Preferences > Add/Remove Software. Type "digital oscilloscope" in the built-in search engine. Once the results come up, select the software labeled "digital oscilloscope" and click the install button. Once the screen shows that the the software has loaded, the window will close. Check the menu. There should be a new section, labeled "Ham Radio". In this section you should find the oscilloscope software. Go to Menu > Preferences > Audio Device Settings. Check to see if you can set the USB soundcard as the audio output. If not, go here to to see a page about installing the necessary drivers. Plug the 3.5mm to RCA cable into the microphone connector on the soundcard. Drill two 7/16 inch holes in the Masonite within six inches of the soundcard. Push the RCA connectors through the holes from the bottom, until the plastic coating is flush with the Masonite(left photo).

Step 15: Making the Oscilloscope Probes

There are various types of oscilloscope probes, such a 1x, 5x, and 10x. Each of these probe types divides the voltage by the number at the beginning of its name. To make a 1x probe, connect a wire to each of the leads of a male RCA connector. Connect a black alligator clip to the wire going the outer ring of the connector, and a red alligator clip to the wire going to the inner pin of the RCA connector. If you want to, you can exchange the red alligator clip for a probe of your choice, such as a pogo clip or minigrabber. Non-1x probes are harder to make, as they need to divide the signals by a fixed number, without creating any distortion. If you want to make other types of probes, go here for a guide. Note: while the guide uses BNC connectors, this project uses RCA connectors.

Step 16: Mounting the Speaker

First, position your sheet of Masonite with the electronics mounted on it in the half of the box with the powerbank in it. Position your speaker next to one of the sides of the box(far left photo). Place your speaker on top of the Masonite and trace around it. Use the Dremel to cut out the Masonite within the area that is marked. Remove the piece of Masonite with the electronics in it from the box. Use the Dremel to make an indentation in the side of the box for the charging cable. Position the cable in the indentation and fill the rest of the indentation with a mixture of the sawdust from cutting the indentation and wood glue(middle left photo). Wait for the glue to dry. Make another indentation for access to the on/off switch on the speaker in the side of the box, being careful not to break through into the indentation for the power cable(middle right photo). Plug the 3.5mm cable included with the speaker into the speaker. Plug the speaker into the charging cable mounted in the box. Plug the other end of the 3.5mm cable into the audio splitter. Drill a hole in the side of the box with the same diameter as the outside of one of the female 3.5mm plugs on the splitter. Push the splitter end through the hole until the end of it is flush with the outside of the box(far right photo). This will be the workstation's headphone audio output.

Step 17: USB Extensions

Plug the two remaining USB extenders into the USB hub. Cut two 5/8 x 3/8 inch holes, approximately two inches apart. Position the USB extenders on the underside of the Masonite sheet so that you can see the entire USB port through the hole(main photo). Mark where the screws will go through the Masonite to mount the USB extender in this position. Do this on both of the holes. Drill 1/8 inch holes in all the positions marked. Screw the extenders in place using the included screws.

Step 18: Mounting the Fan

Plug the USB computer fan into the USB hub. Position the fan in a position close to the Raspberry Pi and as close to the ventilation holes as possible. Trace the circular area with the exposed fan blades on the Masonite. Use the Dremel to cut this area out(main photo). Mark out screw holes for mounting the fan. Drill holes in all the places you marked using a 9/64 inch drill bit. Use the included mounting screws to screw the fan in position.

Step 19: Installing Arduino IDE

Installing Arduino IDE on a Raspberry Pi is very simple. First, make sure that your Raspbian operating system is up to date. You can do this by running the following commands in the terminal.

sudo apt-get update
sudo apt-get upgrade

To install Arduino IDE, simply run this command.

sudo apt-get install arduino

Step 20: Raspberry Pi Indicator Light

If you are very good at soldering, you can remove the green LED on the Raspberry Pi and connect in its place another LED that is mounted on the Masonite panel. However, not being very good at soldering, I simply drilled a hole in the Masonite allowing me to see the existing LED indicator(main photo).

Step 21: Finishing the Electronics

If the barrel connector for the Arduino is connected to the Arduino, unplug it. Plug a nine-volt battery into each of the nine-volt battery clips. Make sure that the barrel connector is plugged into the breadboard power supply and that the switch on the power supply is in the off position. Put the sheet of Masonite with the electronics on it in position in the box(main photo). To use the Raspberry Pi, press the button on the powerbank and set the power switch to on, to turn it on. To turn it off, go to Menu > Shutdown > Power off. Wait while the Raspberry Pi's green LED blinks rapidly for a while then gives one long blink and turns off. Then turn the power switch off. To use the oscilloscope, turn the Raspberry Pi on and go to Menu > Ham Radio > Oscilloscope. To use the Arduino, first plug the barrel connector into the Arduino, then plug the Arduino into the Raspberry Pi. You can program the Arduino from the Arduino IDE installed on the Raspberry Pi. To use the speaker, use the indentation in the side of the box to turn the speaker on before playing audio over it. Alternatively, the station has Bluetooth capabilities and a 3.5mm output, so you don't have to use the speaker.

Step 22: Conclusion and Improvements

That is all that is necessary to build a portable electronics station that will be useful for most electronics projects. I also included an RCA monitor and the circuitry to power the monitor, but as most people would not need this, I chose not to include it in this Instructable. Unfortunately, I was unable to find a way to get the speaker to turn on automatically, so you have to use the indentation in the side of the box to turn the speaker on and off. It should also be possible to design your own amplified speaker for the station. At some point, it would be nice to upgrade the powerbank to a more high-capacity powerbank, one that supported pass-through charging, but this was the only one I could find that had a charge meter and the power switch on the same side. I would also like to design the fan to turn on when a temperature sensor detects a high enough temperature to turn it on, instead of the fan always being on. Those are the only really necessary or pressing modifications to be made. If anyone has any other modification or improvement ideas, please mention it in the comments section below.

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