Help identifying component

[JMCD]

Hiya, well my google fu has failed me...

I'm on a quest to understand my LCD driver a little more. It's a PCB800852.

Specifically the backlight driver portion. In the hopes of modding/replacing it to be more efficient and offer variable brightness from within software.

Can anyone help id the ic highlighted please? I'm trying to find a datasheet for it.

Many thanks!

 

[JMCD]

For completeness I'll update this in case anyone else is looking.

I've managed to ID the model and manufacturer.

Diodes Inc
AP3019AKTR-G1

Looking at the datasheet, it would appear we have a few methods of brightness control.

Either PWM on the CTRL pin or by altering the DC voltage on the FB pin.

I'll update once I've explored both methods.

 

[automatom]

Hey, I'm working with this same board at the moment, only I'm trying to figure out if I can get an audio output. From the research I've done so far I've seen other boards using the 2660 chip offer 4-pin audio connector. But this board seems to be a cut down version. I was hoping there was some way of hacking it to work though. Have you any ideas on that?

 

[JMCD]

Mods please could we move the below to a new thread, it would be better separate for reference?

Hi
I'm probably not qualified to answer this and I've not really investigated audio out from this board... but here's how I see it.

The audio signal is definitely present in the data stream.

The RTD2660 is capable of decoding it.

You can find the datasheet here :
RTD2660 Datasheet

I have no idea if the firmware (that is shipped) on this particular board caters for extracting the audio signal. You could decompile the bin file with Ghidra and take a look.

There is no onboard amplifier so you'd need that on top.

It is most probably achievable with some hacking.

Sorry I don't have a definitive answer for you, maybe someone else may know.

 

[automatom]

Hey, thanks for the reply! I've been scrolling through that datasheet all day but can't really decipher an obvious pin-out for the audio. I'm new to all this so might be missing something. There are references to SPDIF which I remember used to be a cable to connect PC optical drives to your motherboard, so I thought maybe that might be it. Appreciate your help though, it was so random I found this forum, I had the board under my microscope trying to find numbers!!

 

[JMCD]

Hey, thanks for the reply! I've been scrolling through that datasheet all day but can't really decipher an obvious pin-out for the audio. I'm new to all this so might be missing something. There are references to SPDIF which I remember used to be a cable to connect PC optical drives to your motherboard, so I thought maybe that might be it. Appreciate your help though, it was so random I found this forum, I had the board under my microscope trying to find numbers!!

The pins are there yes, but I believe the firmware will be your key.

Think of the RTD chip as a fairly well equipped toolkit, but it needs someone (firmware) to use the tools to be of any use.

There was a project called OpenRTD which is developing an open source firmware. Think it may support the 2660. Maybe take a look there?

Also have a look for the software tools needed to read and write the firmware.

This is done via I2C, in this board you would need a raspberry pi ideally, then you can enable I2C over HDMI in the Pi, connect the hdmi to the display driver hdmi in and use the tool to rip the current firmware (keep that safe somewhere) and upload new firmware.

I can tell you space is limited on the eeprom so custom images would need to be fairly trim.

Happy exploring

 

[automatom]

Hey amazing info man, thanks for that, yeah I've got plenty of Pis lying around. The thing I need to find first though is the audio pin outs as with those I could trace them on the board and see what's happening, also try and connect a basic amp/speaker to see if the firmware has it enabled anyway

 

[JMCD]

Hey amazing info man, thanks for that, yeah I've got plenty of Pis lying around. The thing I need to find first though is the audio pin outs as with those I could trace them on the board and see what's happening, also try and connect a basic amp/speaker to see if the firmware has it enabled anyway

As I said, take a look at the open source firmware and it'll maybe give you a clue as to pinout...

Remember... if you break anything I had nothing to do with it I'm definitely no expert, just my brain rambling a thought process

 

[automatom]

Ah yeah, I get where you're coming from now! Well time to do some digging! Cheers man