Stats:
Made by: Matt
Status: Finished
Tools used: Dremel, Soldering Iron
Introduction:
So this was a project that I always had in reserve if I didn’t have many other projects. So when the world shut down I decided to give this a go. The aim was to grab an old portable boombox from the 90s and breathe new life into it by replacing most of the internal electronics and adding new features. It was initially going to be a small project with just Bluetooth, rechargeable battery and amp but as it continued there was a bit of “feature creep”.
By the time i finalized the requirements I had the the following:
Inputs – Bluetooth and 3.5mm Jack
Rechargeable battery
Visual equalizer
Bass, treble & mid filters
LCD display for track data
A couple of USB ports for charging phones
At first I was going to use a raspberry pi as a receiver with an amp board on top, however its boot time from off to playing sound was over 15 seconds, even with some quick boot tricks to get the operating system running faster. So Arduino stepped up to the role of the controller, after a bit of designing I had a rough layout of all the wiring.
The volume dial is a rotary encoder with a push feature which will be used as mute, I used the standard arduino as I happened to have one lying around and it had enough IO and computer power for this project.
The biggest difficulty was getting the display to show the metadata from the bluetooth module, most bluetooth receivers don’t make this information accessible so I had to get a pricier one that allowed data communication with something such as an arduino. The RN-52 allows you to send a text command such as “V+” to increase volume or “D” for it to reply with track data.
As this was during the first year of human malware known as Covid 19, so without access to the Makerspace for long periods of times the initial focus of work was on the electronics as I have a soldering iron at home.
I’ll be the first to admit the wiring is a messy disaster but its works and will be hidden once the case is closed up.
The bass, treble and mid module here had 3 volume dials which were mounted to the board itself but to fit on the case they were desoldered and disconnectable wires were added, but also added to the mess
Once we were able to return to makerspace the project moved to cleaning up the retro boombox, cutting the holes needed to the visual equalizer and giving a fresh lick of paint.
Visual Eq added.
Undercoat:
Final Result:
The amp circuit can output 20 watts, even on ¼ volume the speaker can flood a small hall. Along with a rechargeable 52 Watt hour battery I have used it for hours at parties and still had plenty of battery left by the end.