Incorporating a PanelPilotACE into the Red Tin Part Three: Strip Board Circuit and Assembling It All
In the final post in this blog series, a more permanent version of the circuit is assembled to connect the PanelPilot Ace to the inner workings of the Red Tin.
In the previous two articles in this series, I outlined how I built a circuit to convert an audio signal to a voltage that the PanelPilot could register, and how I used its PWM Output Channel to control the speed of a fan. All this with the idea of using it for indication and control with the Red Tin DJ system. Now the whole thing needs tidying up and fitting safely and securely into the tin.
Fan control and VU meter combined circuit
First of all, I needed to transfer the circuit I had made on breadboard onto the strip/perf/matrix board (100-4097) . I tried to keep things as neat as possible, but as I started to solder things in place I realised I should have given myself a bit more space to make life easier – I know for next time.
I started off with the envelope follower to control the PanelPilot VU meters, using an IC DIP socket (674-2435) to avoid heat damage during soldering for the NE5532P Op-Amp (081-0188) I was using. I then added the circuit to control the fan and connected the LM35DT temperature sensor (535-9458) .
I decided to use an 8 pin Binder 720 Series socket (046-9020) to connect the circuit outputs to the outside world. I then soldered up a length ribbon cable to the corresponding plug (046-9074) , the other end of which connected to the analogue and PWM inputs on the back of the PanelPilot. As a final touch, I added a yellow LED (451-6543) as a power indicator.
I connected the PanelPilot to the Udoo x86 in the Red Tin, via a spare USB socket. This provided power and meant that once I had installed a copy of the Panel Pilot Design Studio software I could also make any tweaks I needed in situ.
The interface is very similar to the one I designed in Part 2 – a home screen with clickable sections that take you through to screens with more detailed information. I have added a fan speed control button to the Temperature screen. When clicked once this alters the PWM Control by adjusting the Voltage at 0 value in the PWMOutputController Function Element.
This is done by adding a Logic Action with an expression that sets the PwmOutputController Voltage at 0 property to 1, which increases the speed of the fan. Double-clicking the button resets it to its original value.
I had a nice compact, low profile fan (781-5058) to fit in the tin. I found some research on the effects of grill patterns on fan noise and performance. Luckily the grill pattern I liked the look of best - the Loose Swirl - also performed well. I was using a cut-out in the acrylic panel that covers the Udoo x86, rather than a metal grille, as I want the surface to be flat so that I can use my mouse on it if needs be. It also saves a bit of space in the lid of the Red Tin and avoids having something that may hit the screen when the lid is closed.
I imported the swirl image into Inkscape — the open-source vector drawing software — and traced it to produce a vector image, then adjusted the size to fit my fan. When I was satisfied I exported the file as a .DXF so that the Laser Cutter software could read it. I cut a test piece of MDF to check the cut-out fitted the fan OK and then incorporated it into my design for the cover of the top section of the Red Tin.
Fitting it all in
Most of the wiring went via my 8 pin Binder 720 Series socket (046-9020) and ribbon cable. There are some other wires to the fan and temperature sensor that needed making as neat as possible, but they tucked away unobtrusively.
I cut a piece of acrylic to support the PanelPilot and fitted it in the lid of the tin by the side of my main screen. I also cut and bent a piece of acrylic to hold the circuit and support the binder socket and audio input and finished it off with a transparent red top with the Red Tin logo.
The PanelPilot has proved itself to be very versatile and the Design Studio software is really easy to get the hang of. I have been monitoring the temperature of the processor in the Udoo x86 and that is not giving any cause for concern, so the fan control is working as it should be. I am really pleased with the bouncing needles on the VU meters and the voltmeter will really come into its own when running everything from my solar-charged batteries — but the real beauty of this setup is the possibility of easily adapting and developing it further in the future.