Capacitive Touch Faceplate - LXmini Controller with TTP223

[@Mr_Wh1]

Very nice. In case you end up blowing the auxiliary fuse on the 125asx2 module and can't find it, the component/location is called F300. Normally it's a little dark red cube.

[@RobertCowanDIY]

Nice, thanks!

[@BestUnderPressure]

I'm surprised the sensor works that well. I have a project this would be good for. Very cool and sleek design. I love the analog VU meters.

[@RobertCowanDIY]

It took a LOT of tweaking, but it did end up working quite well.

[@James02876]

It's surprising what you can accomplish with a single button interface. Obvious single, double, triple tap, but you can also do touch-and-hold to slowly adjust the VU meter brightness, use a pattern of beats to trigger a preset, and so on. You just need a little micro in there, and some boilerplate code from the web.

[@RobertCowanDIY]

So true! I did think of using a micro to control different behaviors, but it started becoming scope-creep REALLY quick. I landed on manually adjusting the brightness and then using the touch for simple on/off. BUT, there is room to add a micro if I want.

[@c0mputer]

Just subscribed and was looking through your videos and came across this one. It's really funny, I am currently in the middle of a project where I'll be using two TTP223 cap sensors with buck converters to go from 24v to 5v! Oh how the world works. Anyway, have you finished this project up? I'm new to DIY electronics but from what I have been reading buck converters aren't to be used with a light load or no load or else you could get voltage spikes and blow what is down stream. The TTP223 draws too little current so it is a light load. To rectify this you just need to wire a 1k resistor in parallel to the sensor circuit on the buck converter. Did you do this? I don't know if it is actually needed because some buck converters take this into account but this is what I read. Would be good to know when I start the breadboarding.

[@RobertCowanDIY]

Oh, good to know! I did NOT do that, and I did have a few of them die for 'no reason'. This is installed at my summer house, so I'll have to check on it the next time I'm there. Thanks for the tip and keep binging!

[@c0mputer]

@@RobertCowanDIY Ah interesting! If it is in fact spiking due to the light load I really wonder how much and what it looks like. I don’t have a multimeter that can log readings but I bet that could shine some light into it considering a spike could be too fast to see on the display. Glad I mentioned it and I’ll take this into account when I start on my project. Cheers!

[@RobertCowanDIY]

@@c0mputerYeah, interesting. I had a couple fail and just thought it was because they kinda sucked. I really wish I had more room in there. But maybe just a simple LM317 or whatever would work better.

[@c0mputer]

@@RobertCowanDIY True, a lot smaller but then that might require a heatsink. I toyed with the idea of using an lm7805 but without a heatsink it would be like 100°c and probably melt the enclosure I’ll print. Not sure about the lm317. I’m still new to electronics so I’m just going off schematics and what I’ve been reading on forums.

[@RobertCowanDIY]

@@c0mputerGotcha. I think an LM317 would probably be fine as long as you're not asking a lot from it. But a small heatsink wouldn't be much of an issue.

[@markaustin2268]

Can you tell me what electronics you used with respect to the DSP and AMPs?

[@RobertCowanDIY]

Check out this video: kzbin.info/www/bejne/sKbMiZ-upamnra8si=UiUF6kh43sQbb_E9

[@JonathanRansom]

Nice use of capacitive touch! Very clean face plate. Are you leaving it bare aluminum or are you planning on finishing it somehow?

[@RobertCowanDIY]

I'm leaving it as-is. It looks nice enough, I'll just swap out the front panel screws for black.

[@JonathanRansom]

Awesome, I was hoping you were leaving it as is. Looks sweet!

[@RobertCowanDIY]

@@JonathanRansom Thanks!

[@nathanchalecki4842]

Do a test for me please.. if you drop water on the faceplate does it activate the switch? Thanks!

[@RobertCowanDIY]

Hum. I can try that but I'm not really sure that would be an accurate use-case? Or are you trying to figure it out for an application for yourself?

[@nathanchalecki4842]

@@RobertCowanDIY for me. Just ordered pcb's for my bikes digital dash, now wish I had incorporated a touch sensor as it's an easy way to make a waterproof switch (using the whole housing)

[@Handskemager]

Omg, that cnc is using Trumps wig as a dust shoe :o

[@RobertCowanDIY]

ha.

[@Mitch3D]

I never understood how capacity sensors worked, why wouldn’t anything with capacitance activate it? It was actually a problem with my PS4 I had to disable the capacitive switch because it would randomly try to eject the disc.

[@RobertCowanDIY]

Yeah, that's exactly how they work, any change in capacitance makes them activate. Just being close triggers them. So the mass of the metal is detected, not necessarily 'touching' the metal, which is anodized and has no electrical path to the sensor.

[@SarahKchannel]

I would have maybe engraved a third circle as 'touch zone' despite the entire panel being touchy...

[@RobertCowanDIY]

Maybe, but I would have needed to finish that circle, since the whole front panel is brushed and anodized. More work.

[@nathanchalecki4842]

Nah it annoys me that this comment is at the top. It's perfect the way it is, it's a neat hidden feature.

[@RobertCowanDIY]

@@nathanchalecki4842 Kinda same. The whole point was to make it stealth. If I was going to add a 'touch zone' I might as well just add a small switch.

[@GeorgeGraves]

A more professional way would be to dim it according to the room light.

[@RobertCowanDIY]

I thought about that, but that assumes I want it off when the lights are off. Also, what about light bleed from the TV?

[@GeorgeGraves]

​@@RobertCowanDIY Are you just asking questions to get more interaction for the youtube algorithm? Busted! :)

[@RobertCowanDIY]

@@GeorgeGraves No, I'm just pointing out that it wouldn't be 'more professional' to dim with ambient light ;-) I want to control when they're on and off.

[@GeorgeGraves]

@@RobertCowanDIY [raises eye brow] off ----> On dimmed low for dark room ----> Full bright for sunny room. Map between the two using a light cell thing-a-ma-bob. A dual op-amp could do it nicely.

[@gorak9000]

DC to DC buck converters in an amplifier? Is it a class D amp too? Prepare for the wrath of the audiophools...

[@RobertCowanDIY]

Ha. I've been in the audiophile industry for a long time. The DSP will be run from a buck converter, but it doesn't handle any analog signal and should be just fine.