Can I connect to most 1D barcode readers with UART?

[zibidininteki]

I have some of these barcode readers, that have their firmwares failed. They can read barcodes fine, but they don't send anything. That's what the electrical engineer said so. I don't know the details. I was doing some other projects with some other electronics parts before, which they had a bootloader(mostly u-boot), which with UART we connect to that and do our stuff.
I am gonna have to try to repair those barcode readers if they have an OS and a bootloader inside. But do these things have some kind of UART? I was using PL2303 USB to TTL cable, it didn't work. Or does it need some kind of RS232 or some other circuit?
On the left side, there it says SDA1, the other side says RDA2. I don't know what these are?

Here is the insides of this thing:

[cedarlakeinstruments]

@zibidininteki

what the electrical engineer said

So who's this electrical engineer that said that and why can't they provide more information? They clearly know more about this unknown device than a random person on this forum would.

In any case, there's what appears to be a wireless module. Most common interface that is serial, so get out a scope or logic analyzer and start probing pins.

[groundFungus]

If they are oder units, they may be using the high votage RS232 protocol. +-15 for the signals.

Confirm with a instrument as suggessted by
@cedarlakeinstruments

In that case a voltge translator chip will be necessary. Like the MAX232 ( or MAX233 [needs no caps]) will be rewuired to talk to a 0-5V system.

[zibidininteki]

They seem quite new actually, they have SDA1 and RDA2 pins(female) there. I don't know what these are?