So I've got a fun thing that my roommate got at an e-waste place, and I'm gonna open it up and see how it works and if I can interface with it.

It's... a crosswalk button/speaker!

At the bottom it's got interface stuff.
We've got COM and +, USB-B, and unpopulated EXT button and EXT Speaker ports.
There's also some LEDs: Mode, Data, and Audio

And there's nothing on the back, just a grate for a speaker.

There are some labels: EN2 533586 17119416 and V4.05

So, inside. We've got this huge coil thing (more on that later), a single PCB, and a 6W speaker. This fucker is gonna be LOUD, I'm sure of it.

So the coil thing is the button!
See, on the inside of the front, there's a piece of metal, a rubber spacer, and a magnet.

When you push the button, the metal flexes a little, the magnet moves, and this coil can pick it up.

This is presumably used because this is a button that has to be very vandalism-proof

So I pulled the PCB out

Fucking YIKES. This looks like it's both burnt AND corroded?
Did this get hit with wet lightning or something!?

The underside of that big coil.
The three towers on the left are lightpipes for LEDs, and apparently this thing has two separate coils of wire

Here's that little PCB.
one wire is labeled +Pzo, suggesting this is a Piezo Switch.
That makes sense! Piezo switches are known for being very reliable, especially when they need to be vandal-proof.

There's basically no moving parts here, just a piece of metal that flexes a bit and a magnet that sways back and forth. There's very little to break.

Here's the top side of the PCB.
That's more chips than I'd expect!

Also I'm gonna give up on censoring their phone number since these punks at Polara Engineering put it on their damn PCBs

So, U1: It's a Microchip PIC18F46K20-1/PT.
As you'd guess from the name, that's a PIC chip! 64 KB of flash, almost 4 kilobytes of RAM.

U10: a Microchip PIC18F66J50-1/PT.
Basically the same thing. A few more IO pins, I think?

U9 is a Spansion S25FL064P, an eight megabyte SPI flash chip.

U14 is an Analog Devices MAX5408EEE, which is a dual digital potentiometer. This is probably being used for volume control.

U13: Microchip MCP60021 op-amp. Yeah, probably audio.

U11 was a nightmare to photograph.

It's a MAXIM MAX9736A class-D amplifier.

Q6 and Q2 had an interesting time.
It looks like whatever happened blew the chips open!

Also, remember I said there were three lightpipes for the LEDs? Turns out I was wrong!

The left one is a regular LED, the middle one is a multi-color LED, but the right one? That's an IR receiver. You can apparently reprogram these fuckers over infrared!

okay digging into their site to find out info on this thing.
This is apparently an "EZCommunicator 2 Wire Navigator APS System"

And apparently it operators at between 18 and 22 volts.

No response at either of those voltages, though. It uses about 4 watts, but no LEDs light and the speaker doesn't yell SET ID at me.

found the sales manual:
https://polara.b-cdn.net/wp-content/uploads/2023/03/Polara-EZ-comm-2-wire-sales-brochure.pdf

it maxes out at 100 dB at 1 meter, but here's the interesting thing: it apparently adjusts the volume based on the ambient volume?

okay looking closer, I'm not even slightly surprised that it's dead. Look at this, whatever happened was so energetic that it BLEW THE COPPER TRACES OFF THE BOARD

I was gonna say "and obviously there's no point in soldering some bodge wires on to bypass this shit" but if I stick my power supply to the other side, it lights up.
god damn it.

Not the prettiest bodge work I've ever seen but frankly this thing shouldn't be even slightly alive, so it should be happy with what it can get.

So U4 was an LD1086 low-dropout voltage regular.

That was an old picture.

It now looks like this, because as soon as I applied the voltage (at minimum current) it started emitting smoke