Atari Punk Console | Stepped Tone Generator

This is the Atari Punk Console, an easy to build noise synthesiser used that sounds like the original Atari. This circuit uses 2 NE555 IC's and a manufactured PCB, it will help your understanding of advanced electronics and it a good introduction project for those new to IC's and a project worth keeping as it is a fun toy. If you don't fully understand the NE555 or if it a new concept to you, i recommend you watch this video which covers the basics of integrated circuits, especially the NE555.

The supplies needed for the circuit is as follows:

• 1x Atari Punk PCB (instructions for making one are below)
• 1x 9V Battery
• 1x 9V Battery snap
• 2x NE555 Chips with 8 pin holders
• 1x Speaker or buzzer
• 2x 470k Potentiometer
• 2x 100 nF (0.1 uF) capacitor 
• 1x 10uF 16V Polarized capacitor
• 1x 1k Resistor
• Extra wires for soldering

You will also need a safe and organised area supplied with wires and a soldering iron for soldering. For the case and housing you will need a 3D printer if you are planning to print your own casing. I am using a FlashForge Adventurer 4 for this process. The last thing you will need is a glue gun for assembly.

There are many different ways to make this Atari punk with many different schematics online. However, this one that we are using is one of the more simpler ones to construct and understand. The core of this circuit is the two NE555 IC chips in the center, one of them is put into monostable mode and the other is set into astable mode. The first NE555 chip that the current hits is set into the astable mode by pins 2 and 6 being connected together. This creates a feedback loop which constantly re-triggers itself to create a pulse. In other words, in astable mode, the 555 chip oscillates an electric signal between high and low and sends that pulse out via pin 3.

Because pin 3 is directly connected to pin 2 on the 555 that is set to monostable mode, the monostable chip is triggered and produces a pulse determined by the capacitor and resistor in series to it. Because the resistor in series to the capacitor is a potentiometer, we can actually change the resistance of it while on. This means that we can adjust the size of the pulse that the 555 produces. A similar thing happens on the first 555 where the potentiometer can adjust the frequency of the oscillator as it is determined by the resistance and capacitance in series to it.

If the schematic is hard to understand or follow, making the circuit on TinkerCAD is a great way to visualise the circuit and also simulate what will happen if we made it in real life on a breadboard. We will also need this to make a PCB on Fusion360 and send it to a company that can fabricate the PCB for us to work on. 

Instead of a buzzer or speaker in the TinkerCAD simulation, we are using what’s called an oscilloscope. The oscilloscope measures frequencies as a visualisation. When the line goes up on the screen, that means that there has been a high signal (on), if the line goes down the screen, that means that there was a low signal (off). We use this oscilloscope instead of a buzzer because it is easier to know if the circuit is doing what we want it do do.

From TinkerCAD, we can send the model to Fusion360 and save the model on Fusion so that we can send the file to a external organisation that makes PCB's from our fusion file.

To do this, the first step is to click the 'Send to' button on TinkerCAD. A popup should appear with the option of Fusion360 if you have it installed. Click on it and the files from TinkerCAD will transfer onto a new Fusion360 project. 3 separate files will appear. A schematic, A model and a PCB document. The most important file will be the PCB document. Save that as a zip file and send it to any PCB manufacturing company. The one that I used was Wizlogix but there are many and all should have a similar outcome. Send the file and wait for the PCB's to be delivered.

Before soldering all the components into a PCB, I highly recommend that you test out all the components on a breadboard first to see if the circuit is working.

To solder the components into the PCB is very straight forward. Because the PCB already outlines which components go where and gives holes for you to put the components into, it is simple and barely includes any errors or mistakes that you may encounter when soldering on a perf board which is why I prefer working with PCB's.

We can start by soldering in the components that go directly into the PCB without external wiring. These components are the two IC holders, the two capacitors, the polarised capacitor, the resistor and the battery snap. Remember to be careful when soldering the components to not have solder touch other holes apart from its own hole. Otherwise this will create a short circuit. And for the battery snap, red is for positive and black is for negative.

Now that everything that needs to be soldered directly onto the PCB has been soldered. We can solder the components that are not directly connected to the PCB. What I mean by this is soldering the components to wires that connect to the PCB. We do this because the input and output components of the circuit (switch, potentiometers and speaker), need to be outside of the enclosure or at least be able to access from the outside.

Starting with the two potentiometers, line up the potentiometers pins with the hole that they are supposed to go into. Because only two pins from each potentiometer are actually part of the circuit, we only have to solder two of each. Look at the PCB and see which holes are connected to other parts of the PCB. From there we solder two wires of appropriate into the two holes that are needed. Matching those holes with the pins on the potentiometer, solder the wires onto the pins of the potentiometer. Do this for both potentiometers.

The switch is similar to the potentiometers. Instead, we need to solder all 3 pins to the PCB. Same as the potentiometers, we need to align the pins and the holes of the switch and PCB, then cut a wire to a decent length and solder the wires to the PCB first. Following that, match the holes with the pins on the switch and solder the wires onto the switch. Make sure that no solder or any part of the wire isn't touching any part of any other pin expect the pin its supposed to carry the current to.

Lastly with the speaker. It is the same as the rest execpt that some speakers have a positive input and a negative output. For these speakers, just be aware of which pin is which and carefully match the pins onto the right holes by the wire.

If you have already found an enclosure that you can use, then feel free to skip this step. For the majority of people who don't, you will need access to a 3D printer, have Fusion360 and flashprint downloaded and installed.

We will be making an enclosure that can open and close with a dovetail slider. There is a good youtube tutorial here for those that are not experienced in Fusion360. After you have followed the tutorial fully, then you should be able to change the user parameters of the box. This way we will be able to make the box specifically for our atari punk. My user parameters are Length: 103mm, Width: 83mm, Height: 63mm, Thickness: 3mm and Clearance: 0.25mm. You do not have to do the same parameters as me but this is what has worked for me.

After the box is finished we can sketch out holes for the speaker, switch and two potentiometers. You will have to do your own measurements for your own components but if you have the same components as me, you can use the measurements above.

Once the box is fully ready to print, we can export the Fusion360 model as a .obj file and model the file on flashprint or whatever software your 3D printer requires. After that we can start printing and wait.

Once the 3D printed enclosure has finished printing, we can finally assemble the circuit and the enclosure together. It should all be quite straight forwards, the slots in the top of the enclosure are for the switch, speaker and two potentiometers.

Starting with the potentiometers. Slot the dial into the holes in the enclosure. Once we are sure that it fits through, we will have to glue the base of the potentiometer onto the box. I used a hot glue gun to do this procedure but you can use any kind of strong glue as long as the dial doesn't get glued to the base to prevent the dial from turning.

For the speaker, we will need to screw the 4 corners into the enclosure. We have already made holes in the box for the holes to make this part easier. Simply line up the holes on the box with the holes in the 4 corners in the speaker, then get a suitable bolt and nut to secure the speaker onto the surface.

Finally, push the switch through the slot. If your switch has screw holes, you can decide to screw in the switch with nuts and bolts if you wish. However, I find it easier to make the slot to a size where the switch wouldn't be able to move around.

You can also glue the PCB onto one of the sides inside the enclosure so that the PCB is in a fixed position. I would recommend this as components on the PCB could come loose if the PCB is not set properly.

And that is the project finished! Snap a battery onto the battery snap, close the lid and switch on the switch. Turn the dials to change the sound and you have a working Atari Punk noise synthesiser.