![]() For this reason, I reccomend that you use the PICAXE 18X rather than the 18A that I used here (which has been discontinued but it was the one in stock at my local electronics shop). These are an educational variation of the PIC microcontroller family and whilst they have several major limitations, the only one that is going to be a problem here is the memory capacity. Here, I have chosen to use a PICAXE microcontroller. Figure 3 shows the rest of the circuit for the disco lights. I would urge that you also purchase some holders for these bulbs as they get rather hot so the proper ceramic bases are much less likely to cause a fire than any impromptue mounting solution and take it from me, the pins don’t solder well and it’s a pain to change bulbs if soldered to wires. I purchased them from Jaycar Electronics, catalogue numbers SL2741-SL2744. These lamps are rated at 12V, 50W and came in red, yellow, green and blue. Instead of each beat triggering a high voltage xenon flash tube to create a bright white flash, it serves as a cue to a microcontroller to produce the next pattern on a set of coloured halogen lamps. This is where the disco lights are different to the beat triggered strobe light. Disco lights specific circuitry and microcontrollers U2C detects the rising edge and converts it into a brief pulse. ![]() ![]() The 555 timer must complete it’s delay before U2B will allow it to retrigger, forcing a limit on the trigger rate. I have found the music triggering to be excellent, especially when the audio line input is used rather than the internal microphone. I also left out S1 & R18 but it is a matter of personal preference. It is shown in figure 2 below and again is the same as what was used in the beat triggered strobe light, except that instead of an opto-isolator, we take the pulses off to a point marked A. The next section of the strobe circuit is the pulse shaping section. This consists of a microphone amplifier, 2nd order low pass filter and peak detector. For details on how it works, please check out the beat triggered strobe light. Yes it is almost verbatim from the beat strobe, the only differences being the supply voltages. Figure 1 shows the initial analogue processing. If you choose to take this route, just be very careful and check your work as I myself made a few errors along the way, it’s fairly easy with vero-board. Since I did not have any spare strobe boards and the circuit is relatively straight forward, I assembled it on vero-board. In fact, it would be possible to assemble half of the circuitry on the beat strobe’s circuit board, simply omitting the high voltage section and the opto isolator. Most of the circuit is actually borrowed exactly from the low voltage section of the beat triggered strobe light. The substitution would be very simple, just use appropriate pins of the arduino and leave out the programming header (use the onboard USB). These days most readers would likely use an Arduino instead. Note: This project was originally created in 2008 using a Picaxe microcontroller. Some seriously cool patterns can be achieved and the effect is really amazing!Įven better, the effects are achieved using a microcontroller, so you can program your own patterns and effects in fact you can even choose to use your own microcontroller that you are familiar with or if you’re not familiar with microcontrollers, you can use the one shown in my design which can be programmed in either basic or with a flow chart, all you need is a PC with a serial port an old mouse cable & a couple of resistors and you’re away! The Disco Lights project is what you get when you combine the fantastic beat detection circuitry of my ever popular beat triggered strobe light with coloured halogen lamps! In other words, four coloured lights flash in a variety of patterns in time with your music.
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