These are simple modules I made with a pic 12c508 microcontroller. I use them to create different effects. The Mosfets are capable of some decent curernt with very little heating. I have used these for sequential turn signals, flashing brake lights, alternating flashers, strobe effects for leds, fade in out for a dome light etc etc
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Step 1: Picking a Mosfet
there are two ways to do this. Use P channel mosfets to switch the power lead or N channel mosfets to switch the ground lead.
I made an 8 channel one for a traffic advisor clone for my truck. I got a bunch of 3rd brake lights from a surplus house for $2 each. I mounted them to a piece of kindorf and used a couple of muffler clamps to hold it to the rollbar. they all share a common ground lead so P-channel mosfets were used. that requires a 2n2222 transistor to pull the gate down. if you tried to hook the gate to the micro directly the mosfets would partially turn on and heat up. the trick is to always run them fully on or off. there will be very little heating.
Step 2: Single Light Controller
this is the simplest one to build. it can be used for a third brake light flasher or sequential flasher for signal lights that have 2 bulbs in a horizontal layout. This is common on the front on many trucks i've seen..
Step 3: Double Light Controller
This is the one I use for Mustang/Cougar sequential turn signals and alternating headlight or taillight flashers.
Step 4: Triple Light Controller
this one is great for those RGB light strips. You can replace the pic micro with an arduino to make it easier to experiment with. just remember to use digital pins d9 d10 and d11 to drive the mosfets. Many of those strips are common Anode style so you need to use the schematic with N-Channel Mosfets....
i made a small movie of it running the arduino example crossfade sketch
Step 5: Bareduino Version
You can use bare 328P chips on the final board to save on the cost of the arduino.Just use "arduino as ISP" to load your sketch onto the chip. The nice part about loading a sketch this way is there is no bootloader running. that means your program starts immediately at power up. there is no delay from the bootloader polling the serial port.
On my prototype I used a headphone jack connected to the TX & RX pins. I used an old Nokia cell phone programming cable. Just cut off the Nokia connector and solder on a headphone plug. I used the arduino ISP sketch running on an arduino uno with a custom isp sheild to load the nano bootloader into the bare chip. I put a zif on the sheild as I do a bunch of these chips
You can use the uno bootloader if you have a good quality usb to serial adapter. The nokia cable cant run that fast. the nano bootloader is slower and more reliable on slow ports.
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