PART 4 - The soldering - DIY Infrared receiver for Pioneer Tapedecks

If you haven't read Part 3 - start here!

The soldering

As i showed in part 3 i found this old serial IR receiver, i believe i bought it in 1998 for my first DVD PC Player software.

Serial PC IR Receiver

I went to the electronic part store and bought a Stripboard, you can use them for prototyping or like me for small hacks.

Stripboard.

As you can clearly see, it is too large to fit in to the small remote box. So i used the original board as a template.

Find a spot where it fits.

Here you can see the outline of the original board.

Get you saw and cut it along the outline to create you own board from the Stripboard.

The cut-out in the box - fits!

It is not a "perfect" fit, but it will do. Next, solder all the components to the mini Stripboard. For that i need some wires.

1. The Mono Trigger cable. 
2. The Ground cable to provide a common ground between the Remote receiver and the tapedeck.
3. And a suitable USB 2.0 or 1.0 cable to provide the Power +5V for the Remote receiver.

Mono Trigger cable and below the Ground cable.

To get the idea, here how this will be connected when its done. 

Cut all 3 cables to the same length, make the ground cable a bit longer so that you have some slack, when screwing it to the tapedeck later.

I'll jump right to the finished part. Oh, my god, i soldered the components on the wrong side! 😱

Up in the left corner the Red and Black wires from the USB cable provides +5 Volt and Ground. The trigger cable is connected directly to the Out of the IR Receiver. And behind going off to the left is the much thinner ground cable.

Alternatively you could use a minijack Stereo cable instead, this way you would only have two cables out of the Receiver box. The Trigger signal must go the the Left channel (white wire) and the Right channel (red wire) goes to ground. On the receiving end you must then breakout the red wire and connect to the chassis of the tapedeck, because the Control IN connector doesn't provide Ground, as discussed in Part 1 of this Blog.

As you might see i have bend the pins of the IR Receiver in a S-Form because it is a relative big component. If i soldered it directly on the board it wouldn't have fit inside the box.

All soldered.

The other components were soldered on to the board just like on the breadboard. You can see that i mounted the both capacitors horizontally, so that they fit well inside the box.

This all depends on your box size.

Me trying to fit the 3 cables in a way that all gets out of the same hole!

I snapped the lid on and connected it the the Pioneer tapedeck.

Trigger cable goes to Control IN and the ground wire is screwed onto one of the screws on the backside.

So everything is hooked up - all i have to do now is to test the end result.

Roll video:

That's it! I am so happy with this solution.

The good thing about this hack is, you can use it with any of the Pioneer CT-S models that have a Control IN Port on the backside.

Here is small list:

CT-95, CT-43, CT-S900S, CT-S910S, CT-S920S, CT-S810, CT-S820S (obviously), CT-S830S, CT-S710, CT-S720, CT-S730S and on and on the list goes.

Hope you liked this DIY blog. Please write a comment if you did!

Cheers 🍺

Per

Go to Part 5

PART 3 - The control bus - DIY Infrared receiver for Pioneer Tapedecks

If you haven't read Part 2 - start here!

The Control Bus

Like a real bus bringing passengers from one station to the next and so forth, the control bus from Pioneer, called SR (System Remote), is bringing IR data (binaries) from  the Receiver or Amplifier to the tapedeck, if the binary data wasn't meant for the tapedeck, you can connect that to the next unit and that to next again. Every unit is listening for signals.

So you can daisy chain the units, Amp to Tapedeck, Tapedeck to CD player, CD Player to Tuner, etc. etc.

I found Adrian Kingstons great website, which in detail describes the Pioneer SR format.

http://www.adrian-kingston.com/IRFormatPioneer.htm

From his website i learned the following about the control bus:

"This is simply a TTL +5V rail supplied by the receiving end (CONTROL IN). The sending end (CONTROL OUT) pulls this rail down to 0V (GND) with pulses that are the same as the NEC protocol described above except that the pulses are unmodulated, that is there is no 40kHz carrier inside each pulse, its just a solid period of 0V."

With the important note:

"Note that the tip pin of the CONTROL jack plug is the SR bus pin and the ground connection between the units needs to be made with an audio ground from the LINE IN/OUT connectors."

Lets boil that down to the following.

• Must buy 40kHz IR Receiver.
• I need +5 Volt and a common ground.
• The output of the IR receiver must be +5 Volt.
• Any signal coming out of the IR receiver must pull the +5 Volt down to 0V.
• the CONTROL IN supplies +5 Volt ?? - really?

I found this TSOP31240 IR Receiver Module running a 40kHz in a range from +3V to +6V.

It's a good ideas to protect the IR Receiver against EOS (Electrical Over-stress) and in general to stabilize the Receiver with the following components. Sometimes IR Receiver are sold on a mini-board with these components already mounted and ready for user with an Arduino or other micro-controllers.

So this is what i came up with, i measured if ground comes out of the CONTROL OUT connector. And just like Adrian wrote on his website, ground is not connected at all.

Me, measuring ground to ground - no result.

I then measured if the IN or OUT provides +5V. Yeah, well OUT does provide +5V, but it's the data line which is always high +5V. To use the data line as power provider for the new IR Receiver is not a good idea. (trust me i tried)

So i am stuck with using an external power supply for my design.

Components line-up to test with the breadboard:

The usual suspects...

From left to right:

• The IR receiver TSOP31240 (40kHz) Pins from left to right: 1. Ground, Vcc and Out
• Electrolytic capacitor 10V 10µF 
• Ceramic capacitor 0.1µF
• Resistor 10k Ω (long legs)
• Resistor 100 Ω (short legs)

(See also the Schematic Diagram above)

This is how i hooked the components up on the breadboard.

Breadboard with components seen from behind.

Please note that the electrolytic cap minus pin must go to ground. the black cable going off to the right is Out. No signal from remote and it is high (+5V), any signal should pull it to Ground.

As a power supply for this test i used an Arduino clone.

Mini-scope with breadboard.

I plugged the Mini-scope (5V per division) on Ground and Out, then pressed Tapedeck Play on the Logitech Remote control.

YES - ITS ALIVE!!

In Trigger mode you can see the Play Button IR codes as they are pulled down from +5V to Ground.

Lets plug it in the Pioneer CT-S820S CONTROL IN port.

I only had a stereo cinch to mini-jack cable, that's fine. Left channel (white) is the data line. For the real setup i will use a mono trigger cable as they are called.

Note the dodgy ground wire to in the upper left, clipped to one of the chassis screws. The Uno's role is power supply.

Roll video:

Sorry about the dishwasher noise in the background, meh! Thou shall have clean plates!

I am really surprised that it just worked like that. Really great news.

Next steps: 

• Get some nice cables.
• Solder them on board.
• Throw it in a nice package.

I found this package from 1998, this will do fine. Old serial remote receiver box.

Go to Part 4.