Low cost Arduino based total amp control

[zdr]

The goal is to use already available arduino parts from ebay, and to produce following functionality:

1) IR remote control for power on/off, channel switching and volume
2) Softstart
3) Temp display and control
4) LCD info display on front panel.

So far, I got this working without volume control. I am waiting for LDRs to arrive.

eBay part list:

1) arduino nano clone: 2 eur
2) 4 channel relay pcb: 2 eur
3) 1602 LCD: 1.5 eur
4) IR remote: 1.5eur
5) temp sensor: 1.5 eur
6) cables, headers, resistors: 2eur
7) LDR: 10 eur.

Software is already written, up and running. Tactile buttons for channel switching and power on/off are also included, but I think I am going to get rid of those and have IR only control.

 

[ric-paul]

Great project! Did you write the software?

And I'm missing what you need the LDR's for.

I have one of those Arduino clone boards intended for converting the outputsignal of my car's steeringwheel controls to an aftermarket radio, but haven't done much research yet.
Price of China made stuff is rediculous. So is quality at times... (for amplifierboards, I have seen errors in connections many times, and supposedly layout is often lousy as well).

 

[zdr]

Thanks. LDRs are planned for volume control, but I might go with PGA2310 instead. I am writing software myself, and it's quite trivial with all given arduino examples.

Last addition is a "back" button on remote, for fast A/B source switching without shifting a finger It alternates between current and last input selection with one button. I miss that functionality I used to have in my old Sony CRT

I might add IR learning functionality as well, so that any remote can be added. Waiting for ESP8266 module to arrive so that it can be controlled over wifi too.

I also ordered a nice 2.42" OLED display from eBay, these cheap 44780 LCDs are too small and with crappy contrast.

 

[wineds]

Seems very similar to this thread zdr :

http://www.diyaudio.com/forums/anal...d-ldr-volume-source-selection-controller.html

 

[zdr]

Wow, thanks. I did search before creating this thread but missed it.

Sent from my Nexus 6 using Tapatalk

 

[zdr]

I will be keeping this thread open, as I think I might be able to develop similar functionality for around 30eur, without any wired input though, and by using H11F1 which is available as a sample.

 

[wineds]

The H11F1 is an interesting device zdr! There does seem be distortion issues when used as an attenuator unless the signal level is kept low?

 

[wineds]

It looks like they are re limited to about 150mv before distortion kicks in?

 

[zdr]

Yes, they are dropped from project already Back to LDRs.

 

[zdr]

It seems it's possible to turn on 16bit pwm on two pins, 9 and 10, which could allow direct drive of ldrs. Problem is, we need 4. Actually, 16bit precision is required for values above 1k only, 8 bit is fine for below 1k. I am trying to figure that one out.

Sent from my Nexus 6 using Tapatalk

 

[zdr]

I must say, Vincent77 did a great job with his project. I couldn't even make a cheaper variant without cutting too many corners. The most expensive part I guess are the relays, so for single ended output switching half of them can be omitted on IO board, and the last half replaced with cheaper ones.

 

[hahfran]

Thanks. LDRs are planned for volume control,

i was informed however some 10 years ago some types of LDRs produce much noise. Are there any noise specs available?