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Internet Radio Part 2: by Phil Prosser This new Internet Radio, introduced last month, is very capable; it runs your choice of media player on Linux with a large touchscreen. It’s built using pre-assembled modules and 3D-printed pieces, so once the parts are ready, you can put it together in an afternoon. T he first article last month described our goals, its resulting capabilities, the 3D-printed case construction and how the modules connect together. If you’ve decided to build it, by now you should have the case pieces ready and the modules in hand. You should also have the operating system installed on the Raspberry Pi. That means we’re ready to put it all together! Mechanical and electrical assembly First, check the fit of the Raspberry Pi into the case. If any dags need to be cleaned up from the slots for the Pi, do this now. The Raspberry Pi installs by inserting the corner next to the USB-C connector and then rolling the Pi in, so the corner at the far end from the USB faces up to its matching slot. After that, jiggle the front slot in. It is somewhat tight, but it fits – refer to Photo 4. Leave the Pi loose until the HDMI and USB-C connectors are in, to make it easier to jiggle those into place. We have included screw holes on the fourth standoff for the Pi. If yours is loose, you can use a Jiffy box screw to hold it still, but we did not need to add this screw. Next, install the DC-to-DC converter using 9mm Jiffy box screws and flat washers to the screw holes printed under the handle. Mount it with the wires facing the rear of the case – see Photo 5. Wiring 1. Solder 150mm extensions to the power input pigtails using red and black light-duty hookup wire. We want sufficient length in these to allow easy assembly. Use 10mm lengths of 3mm heatshrink tubing to cover where the wires are joined. 2. Run the USB cable under the Pi Photo 4 (left): when installing the Raspberry Pi, start with the back corner and roll it into the slot. In this picture, the Raspberry Pi is half installed. Photo 5 (below): the power supply (highlighted in yellow) screws into holes printed into the top of the case, underneath the handle attachment location. siliconchip.com.au Australia's electronics magazine March 2026  71 Photos 6 & 7: the input wires & switch connection on the amp module; the middle input pin (ground) is not connected. The two black wires go to a switch that allows us to select between Bluetooth and the Raspberry Pi input. Connect the amplifier’s audio input ground pin directly to the power supply V− output. to keep things neat and plug it into the power connector. This is a snug fit but it goes in. 3. Prepare to install the amplifier. There are two sets of wires that need to be soldered to the amplifier board, for the input selector and audio input: 4. Solder 300mm lengths of red and black light duty hookup wire to the audio input connector “IN” left and right pins; these are the outside ones (Photo 6). 5. Connect a 300mm length of green light-duty wire to the power V− pin. This means that the middle “GND” pin on the input connector is not used, and the green ground pin goes to the amplifier module V− connection – see Photo 7. Put a 30mm length of 5mm heatshrink tubing over these, snug up against the PCB to keep them tidy. 6. Now terminate these three wires to a 3.5mm stereo jack plug (see Photo 8 & Fig.7). We also need to include a 400mm length of light-duty green wire, which will extend from this plug through to the power supply ground point on the rear panel. 7. Put a piece of 5mm heatshrink over the wires, making sure that the green wire goes to the outermost connection, and also that nothing shorts. Be sure to put the backshell on the wires before you solder it all together. Use a pair of pliers to gently crimp the strain relief over the heatshrink, securing the wires, then screw the backshell on. 8. We now need to connect to the “SW” connection on the amplifier PCB. This connection switches between the Bluetooth module and the “IN” connector. Use two 250mm lengths of light-duty hookup wire; these can be any colours as they only 72 Silicon Chip go to a switch. Solder these to the two “SW” pins and then put a 15mm length of 3mm heatshrink over these at the PCB to keep things tidy. 9. Use a zip tie to secure these wire bundles to the rear mounting hole of the amplifier board. This will stop the wires from bending and causing shorts and breaks at the solder connections. 10. Solder these two wires to an SPDT toggle switch and insulate with heatshrink. Make sure you insulate the connections at the switch using 3mm heatshrink. The final arrangement is shown in Photo 10. Photo 8: the wiring to the 3.5mm plug that goes into the Raspberry Pi. This includes an extra ground wire soldered to the ground tab that runs to the power input connector. Keep this tight, and it will still fit in the backshell. 11. Use light-duty hookup wire for the power and speaker connections, all 340mm long. We used red and green for the speaker connections. You only need to connect to the V+ input on the power input as the ground goes via the 3.5mm jack. These wires are connected via pluggable two-way headers. If you don’t have the right crimping tool, simply use sharp pliers to secure the wire in the crimp, then add a small amount of solder. Make sure you get the power connection correct; the positive is closest to the corner of the amplifier board (as shown in Photo 9). Photo 9: the power wiring for the amplifier. Photo 10: the amplifier module, wired up and ready to install in the case. Fig.7: the wiring for the 3.5mm jack plug. Note the two ground wires of different lengths; in practice, it’s easier to solder one to the top and one to the bottom. Make sure it will still fit in the shell despite the extra wire. Australia's electronics magazine siliconchip.com.au 12. The speaker connectors terminate at the speaker terminals; use 30mm of heatshrink over these as it assists with strain relief and keeps things tidy. Now install the amplifier PCB in the case. It is held in by its volume control shaft bush and two ridges printed into the inside of the case to keep it aligned properly. Make sure the board is aligned with the ridges and tighten the pot nut well. We have also printed an indent in the case to accommodate the locating lug on the volume control, so everything should sit neatly. Next, plug the 3.5mm jack into the Raspberry Pi audio output connector. Mount the input switch to the case, making sure to put a shakeproof washer on the outside. Tighten this well. Plug in the power connection and the speaker connectors, making sure not to mix these up. We labelled our cables so it is less likely we will make a mistake. Use a 100mm zip tie to secure the input wiring to the DC-DC converter. We will come back to the flying leads for the power and ground connection when we wire up the rear panel. Photo 11: the LCD screen has an onboard on/off switch that needs to be left on. Mounting the handle We used four 16mm-long M4 machine screws, washers and nuts to do this. Use shakeproof washers to ensure these bolts remain tight with movement and vibration. After that, you can install the LCD screen. We built two Internet Radios to check the design & instructions and found that the LCD alignment between the top and bottom was asymmetrical on one of our units, while it was perfectly centred on the other. This really affects the mounting hole locations. We worked around this, but on visiting Altronics the next day, we checked a few other samples and found that they were all well centred. The staff offered to swap the crooked unit, but we had a fix, and it seemed wasteful to scrap an otherwise perfectly functional unit. If you experience this crookedness, we drilled new 2mm holes in the back of the front panel and used them to attach the screen with 6mm-long self-tappers. Now check that the screen’s “On/ Off” switch is set to on, as shown in Photo 11. Present the LCD to the internal front panel; the connectors face the wide section. Install self-tapping Jiffy box screws in the three holes you can siliconchip.com.au Photo 12: the connections for HDMI and USB to the LCD screen; this is tight, but it does fit. The USB socket is for power and touch sensing. Photo 13: the Raspberry Pi in the case and plugged in. The cable at the bottom supplies power to the LCD screen; it pokes out of the USB hole in the rear of the case a bit. Australia's electronics magazine March 2026  73 Photo 14: the wiring from the power input to the switch and bypass capacitor. We use the leads of the capacitor as connection points for the amplifier and Raspberry Pi power converter wiring. Photo 15: the finished rear panel wiring. The top four new connections are both for the speakers. access. The Raspberry Pi obstructs one, although you may be able to get a screw in if you take the Raspberry Pi out. Three is enough, though. The next bit is one of those jobs where having three hands and needle-­ nosed pliers for fingers would be really helpful. Go steady, as it does all fit. First install the 90° HDMI connector to the HDMI input on the LCD screen. We then used the provided short HDMI to HDMI cable and connected it to the Raspberry Pi’s micro HDMI connector via a right-angled HDMI adaptor and a micro HDMI to HDMI adaptor. You may find alternative parts and approaches, but this fitted well for us. Again, everything is very snug, so gentle persuasion is the order of the day. Now install the micro Type-B USB to Type-A USB cable, which is in the LCD box. This goes from the “TOUCH” connector on the LCD to a USB Type-A port on the Pi. Secure this to the HDMI cable with a couple of cable ties. Photos 12 & 13 show where things go on the LCD and Raspberry Pi. Now turn your attention to the Radio’s rear panel and mount the barrel power input connector and power switch. Photo 14 shows how this should look. The middle pin of the power jack is normally positive; this comes out in the middle of the socket. However, do check that your power supply’s centre pin is positive first. Start by installing the 2.1mm barrel connector and a SPDT switch in the rear panel, then add the supply bypass capacitor. This needs to be rated at 35V (or more) and at least 1000μF. We used a 2200μF, 50V capacitor. We have printed a holder on the rear panel that suits an 18mm diameter capacitor. Insert the capacitor in the holder and bend the leads as shown to connect to the power input connector. The negative pin of the capacitor goes to the barrel connector on the socket. This is at the top in Photo 14. The positive pin of the capacitor goes to the switch; this might need to be extended with a short length of wire. You should not need to glue the capacitor as, with the snug fit of the holder and the leads being bent and soldered to the barrel connector, the capacitor will be secure. Next, solder a 75mm length of red light-duty hookup wire to the outer terminal of the switch; this goes to the positive pin of the barrel connector. Insulate these joints with two 15mm lengths of 3mm diameter heatshrink tubing. Make sure that you leave 5-10mm of the capacitor leads free, as these form your positive and negative power supply connections. At this point, you should have two positive and two ground wires waiting to be connected, one pair from the DC-DC converter and the second from the amplifier power connections. Solder the power wires from the DC-DC converter and amplifier to their respective connections on the capacitor. Now connect the amplifier output wires. These are 340mm long in red and green, with pluggable headers for the amplifier end. Solder these to the speaker terminals and insulate with 15mm of heatshrink tubing. Refer to Photo 15 for how this should look. At this time, you can plug in the 74 Silicon Chip Australia's electronics magazine amplifier output wires and zip-tie them together. The final looming should protect the solder junctions from being flexed and make things quite tidy. Now install the speaker terminals. We have printed holes to accommodate combined screw terminal/banana sockets. Mount these and connect to the wires coming from the amplifier board. We have included printed feet in the case design, but it’s ideal to stick four rubber feet to the bottom of the case. At this point, all the internal wiring should be finished, with a few zip ties added to keep everything neat and tidy, like in Photo 16. Clip the rear panel on. This will require you to fit the LCD USB cable through the hole in the rear panel. It should all go together very neatly; the inbuilt clips hold the rear panel in place. There are four screw holes into which you can insert 9mm Jiffy box screws to hold it together. You should be able to power up the central unit and get to the Raspberry Pi desktop. Optional speakers We used fairly low-cost Altronics C0635 100mm drivers. We tried cheaper ones, but preferred these. Because the boxes are built to the size available, we have made them sealed, which tends to roll the bass response off early, avoiding nasty peaks that can occur with poorly designed bass reflex alignments. We then use the equaliser in VLC media player to correct this early rolloff, which works surprisingly well. siliconchip.com.au The underlying hint here is that unless you really do some homework, spending too much on the drivers is probably a poor investment. Building the speakers is straightforward. Use four 9mm 4GA Jiffy box screws and 3mm washers to attach the drivers to the case. We have included pilot holes in the 3D print, so you should have an easy time locating the screws and drivers. Install the speaker connectors in the holes in the rear panel and solder light-duty hookup wire to the speaker terminals – see Photo 17. Get some fibre fill; sheep’s wool or anything that is likely to absorb energy from resonances, and stuff the speaker loosely full. In our case, it was about a 150mm square piece of fibre wadding that we found in the sewing cupboard. Pretty much anything like that will do. Now secure the rear of the case with four more 9mm Jiffy box screws. We have printed feet on the unit, but if you’ve stuck rubber feet on the main unit, it’s best to do the same on the matching speakers. Note that if you want to bolt the speakers to the central unit boombox style, you should do this using M4 machine screws prior to installing the Raspberry Pi (or temporarily take it out to attach the speakers). At this point, you should be able to wire the speakers to the terminals on the main unit and power the system up. Getting it up and running We can now connect everything together and set it to work. Power the system up and open VLC Media Player. We went to the main menu, right-clicked on VLC and added it to the taskbar. Out of the box, the Pi drives the 7-inch LCD screen well, but if this is to be a dedicated media player, you probably want a simplified display and much larger fonts and buttons. Setting up the display to use large icons and text is not hard. 1. Click the Raspberry icon and scroll down to Preferences. 2. Select the “Appearance Settings” tab. 3. Go across to Defaults. Click “Defaults” against the line “For Large Screens”. 4. Click OK. If you have another monitor, a micro HDMI cable can plug into the second video port and run through the rectangular cutout in the rear panel. The Raspbian system deals with this pretty much exactly like a Windows or macOS system. We won’t go into detail here, but encourage you to explore some of the extensive documentation online and learn the subtle differences that exist. Setting up media streams This bit is probably as fiddly as it will get. The aim is to create some desktop icons for your favourite radio stations that you can simply double-­ click on to launch VLC Media Player and listen to them. Not every station has an internet stream, but it seems that most do, and worldwide there are thousands. There are websites that list the addresses for radio stations; this one worked well Photo 16: the fully assembled unit, with the wiring zip-tied together. The final product should be pretty tidy. Photo 17: assembly of the speakers involves little more than installing the drivers and some sound-dampening material. siliconchip.com.au March 2026  75 Table 2 – Station name Link 3D Radio http://sounds.threedradio.com:8000/stream ABC National https://mediaserviceslive.akamaized.net/hls/live/2038318/rnnsw/index.m3u8 ABC News http://live-radio01.mediahubaustralia.com/PBW/mp3 Triple J unearthed https://mediaserviceslive.akamaized.net/hls/live/2038305/triplejunearthed/masterhq.m3u8 MMM Adelaide http://legacy.scahw.com.au/5mmm_32 The Bone FM San Francisco https://playerservices.streamtheworld.com/api/livestream-redirect/KSANFM.mp3 Triple R http://realtime.rrr.org.au/p1h for us: https://fmstream.org/index. php?c=AUS This site has a massive list. If you select “Links”, you can copy the web links below. Put the text into a file with the extension “.m3u”. Some example links to internet radio stations are shown in Table 2. Our approach to this Internet Radio is more about making a really simple way for you to get going with the Linux environment, avoiding unnecessary complexity. Once you are happy with what we have set up, we are sure you will seek more complexity and move on from this minimum but sufficient capability. To create some desktop icons, you can: 1. Click on the Raspberry symbol in the top-left corner of the screen. 2. Scroll down to “Accessories”, then choose “Mousepad” from this Screen 5: opening the mousepad program in Raspberry Pi OS. menu (see Screen 5). This will open an editor screen. 3. Type http://sounds.threedradio. com:8000/stream 4. Click “File” in the top menu. 5. Select “Save As”. 6. Double-click on “Desktop” to save this to the desktop. 7. This will open a screen with “Name” at the top. 8. Type “Three D Radio.m3u” (see Screen 6). 9. Click Save in the bottom-right of this window. 10. Close all the windows you have opened. You will now see an icon on the desktop named: “Three D Radio.m3u” (Screen 7). The m3u extension indicates that this is a stream, and VLC should open it. Double-clicking this icon will open VLC Media Player and start streaming the station. You can do exactly the same for any station with an internet stream that you choose. If you only have a few stations you want to play, which is true for most of us, this will be a good way to start. Similarly, if you have a folder with a load of music files, you can use VLC to play them. Setting up VLC Screen 6: using mousepad to save the file “Three D Radio m3u”. 76 Silicon Chip Australia's electronics magazine Why do we recommend VLC for this project? VLC media player is baked into the full Raspbian install, and it ‘just works’. Even in 2001, when we first saw VLC, it was famous for playing anything. Over the intervening years, development has continued, and it remains a very stable player that many people will be at home with. Now let’s apply some equalisation to the speakers. The ones we’ve designed are not hifi, but with the power of the Raspberry Pi and VLC Media Player, we can add equalisation to get the most out of them. Open VLC Media Player, select “Effects and Filters” (Screen 8) and you will find a 10-band equaliser (see Screen 9). siliconchip.com.au We needed to change the sliders on each band, then click Enable a couple of times to update the EQ. If you add a lot of gain to the bass, you will find the system clips, so you will need to reduce the gain on the leftmost slider, “preamp”. We recommend that you fiddle with these until you are happy with the sound from the speakers you have chosen to use. If you are running the Internet Radio from a 24V plugpack, you will have oodles of power that can be used to get some bass boost, but be aware that you will probably run out of physical capacity in the speakers (principally cone excursion) before the amplifier runs out of power. The speakers specified needed some bass boost, with the midrange attenuated and treble boosted, in a typical ‘loudness’ curve (see Screen 9). This counteracts the roll-off these speakers exhibit in such a small box, and the final result sounded way better than we expected. The 7-inch screen we’re using is more than enough to drive VLC, but for anything beyond that, it is not large enough. If you want to use the Internet Radio for anything more than playing music, plug a micro HDMI to HDMI adaptor into the second HDMI port on the Pi. Assemble it with the HDMI socket outside the case; the cable will fit through the hole we have for the USB connectors. You can then plug in a decent external monitor. That will give you plenty of real estate to work with. If you want to use this computer for more than just music, we recommend that you get yourself a Raspberry Pi 5 with 8GB of memory (16GB is available, but there is a big step in cost). The Raspberry Pi 5 does not have a 3.5mm audio socket, so you will need to add an audio output. You can do this by adding an audio DAC Hat, such as the Raspberry Pi DAC+, or you can plug in a USB audio adaptor. To set these up, click the audio icon on the top right of the screen, and select your audio interface. Screen 7: internet radio links on the Pi desktop. Double-clicking these will launch VLC Media Player and open the stream. Screen 8: VLC’s Tools menu lets you open the Effects and Filters dialog. Conclusion Wow, you’ve built a Linux-­powered Internet Radio boombox and computer. We trust that you got this working, and for those with little Linux experience, that it went well. We look forward to hearing how you modify SC and tailor this to your needs. siliconchip.com.au Screen 9: click on the “Equaliser” tab on the left and adjust the EQ until it sounds good with the speakers you have selected. Australia's electronics magazine March 2026  77