Finally, some pictures and a video clip.
The main PCB:
The touch PCB:
Completed:
Function video clip:
Category Archives: Showcase Lighting
The circuit of the control unit for my showcase lighting is very simple. The core is the microcontroller MSP430G2553. A linear voltage regulator generates the required 3.3 V. The board has 2 connections for LED strips that are driven by a MOSFET. The brightness information is passed on to the ADC of the controller with a photoresistor and is evaluated there. Most I/O of the controller are required for the 5 capacitive touch fields and the feedback LEDs.
Dimming is done by PWM.
Assignment of the 5 touch fields:
- Cap_Middle: Manual lighting on/off (1s touched), reset of settings (2s touched), saving of settings (3s touched); The feedback is via the surrounding LEDs
- Cap_Up: Brighter
- Cap_Down: Darker
- Cap_Right: Upper turn-on threshold; A touch will take the current brightness
- Cap_Left: Lower turn-on threshold; A touch will take the current brightness
I would like to have a solution for my showcase lighting which is small, simple, inconspicuous, but chic.
There are 2 showcases to be illuminated. LED strips are already installed in the showcases, once 2 and once 3. The strips are operated with 12V. The power is about 3Wmax per strip. For 5 strips, this is 1.25 A, which is not to much. In addition, this is much too bright and will probably be operated mostly dimmed.
Power supply is a 12 V plug-in power supply. To build something by myself is not necessary.
Since I like to try other things, I did not take an Arduino, but a TI MC of the type MSP430G2553. For development, I got the launchpad MSP-EXP430G2 , which already brings the programming interface for programming my own board later. At the same time I didn’t want any buttons and found the idea of capacitive switch fields very elegant. The MSP430 Capacitive Touch BoosterPack is compatible with the Launchpad.
There are Code Composer Studio builds for Windows, MacOS and Linux, however, the MSP-EXP430G2 is not supported in MacOS, so I had to take the Windows version🙁.
Perhaps you know this too: You have finally decided for a new living room furniture and maybe this includes also a glass showcase. If that would be illuminated … (I know, this is old-fashioned (or a matter of taste)).
Something like this is well-known for a long time. Problem with this: with normal incandescent light it is expensive and if you have to switch on the lighting manually, you will not do it anyway.
Today, LED strips are used. A problem remains: manual switch-on is uncomfortable.
I faced this problem a while ago.
The available automatics were expensive and / or crap and did not what I wanted anyway.
I don’t want to have to worry about this lighting again after I first switched it on, if I don’t want to.
The following characteristics are important to me:
- Lighting dimmable
- Lighting is off when it is bright outside
- Lighting is off when it is night and the room is dark
- The thresholds for switching on and off are adjustable
- I can save the settings (optional)
The next contributions show how I solved the challenge.