24 Channel USB Connected LED Controller, upto 1A per Channel

This device was designed to be a versatile high-current LED controller, with the ability to sink or/and source high currents, up to 1A per channel with dissipation of up to 1w per channel. Using the various jumpers, the LEDs can use voltages from 5v-36v as long as each channel stays under the transistor's max dissipation.

Easily controls, 5mm LEDs,1w LEDs, 3w LEDs, 3w RGB LEDs, 5w RGB LEDs, 12v RGB Lightstrip, 12v solid color light strip, common anode RGB LEDs, common cathode RGB LEDs. Any combination of LEDs in parallel/series. Whatever kind/wattage/configuration can be made to work, to a max of 1A per channel or 1w dissipation.

A PIC18F4550 controls 24 high-current darlington transistors. The PIC is ready for USB Communication and using Microchip's Library there is a multitude of USB connected devices can be made. From a simple serial port, keyboard, mouse, HID, MIDI Devices, Audio Devices, and more.

There are 4 pins left to use for other purposes, such as AdC, more transistors/mosfets, shift register whatever is needed. Accessed via the 6-pin polarized header.

This Instructable will only cover the building of the circuit and cover the basic firmware that is currently ready for release. It accepts data from a PC/MAC/Linux over emulated serial port to the circuit board which outputs 8-bit PWM for all 24 outputs.

I have Kits For Sale in My Store and all the files to recreate this project is in the ZIP file below.

The current kits have are the v.2 Hardware, shown in this Instructable. The v1 hardware project files can be found in the ZIP. 
Changes v1 to v2
- A few parts are repositioned
- Lables are moved
- v2 has Top-side copper, v1 uses jumper wire(more DIY friendly)

Datasheet, Updates and More Info Can Be Found On My Site

2/10/12: Update, a new firmware is almost finished for control of RGB LEDs and single color LEDs, will have the ability to create patterns on a computer and upload to the controller to run the patterns by itself. Also greater and easier control of streaming data to the device, to control it live from a computer.

Step 1 Supplies

The Eagle Files for version 1 are available Here

Electronics: You Can Purchase a Kit in My Store

• 18F4550, DIP
• Circuit Board Buy One
• 24x MPSW45AG Darlington transistors or similair
• USB Type-B jack, board mount
• 20 mhz series oscillator
• 10kohm 1/4w resistor
• 24x 220 ohm 1/6w resistor, might vary depending on transistor
• 220nF disc capacitor
• 2x 0.1uf disc capacitor
• 2x 1uF electrolytic capacitor
• 5 pin ICSP header, optional
• 6x 4-position terminal blocks
• 2-pin header, KK6410, optional
• 2-pin housing, KK6471, optional
• 6-pin header, KK6410, optional
• 6-pin housing, KK6471, optional
• 8 wire crimps for housings
• 7805, 5v regulator, optional, can't be used in most cases

Tools:

• Soldering Iron
• Diagonal Cutters
• Wire Strippers
• Flat screw driver for terminals
• Multimeter

Other:

• USB Type A to Type B cable
• LEDs, I have some in My Store
• Resistors for the LEDs

Comments

[simmunity]

I've been busy and just got around to updating my CCS PIC compiler and bringing up the three 24 channel boards I bought and assembled. I built an adapter for the CCS ICD-U40 programmer I use and substituted a 47k ohm resistor between MCLR and 5 volts instead of the 10k one provided. I had an invisible solder bridge between PDC (programming clock pin and ground) that I had to find with a meter and cut open. The board has very tight trace spacings so be careful.

Finally a significant oversight with the parts supplied with the kit is that it is missing two 15pf (surface mount) capacitors that go to ground on each side of the crystal. Without those the crystal and oscillator circuit will not start and run correctly. All the CCS prototype boards and Microchip's data sheets and schematics include them when using a crystal. After I added those and programmed the PIC with a color changing patter on an RGB LED, the board worked perfectly. Very pleased with the result.

[ChromationSystems]

The oscillator starts and runs correctly, the oscillator capacitors were excluded to allow the circuit boards to be one sided, to make it more DIY friendly. Though it would be better to have them included. There are 2x 100nF capacitors on the v.2 PCB, those could be soldered on the bottom of the board, directly to the PIC's Vss & Vdd pins.

[simmunity]

One detail is that the kit comes with one 100nf cap and that should be soldered as close as possible to the power and ground pins on the chip, not off to the side as recommended. The reason is that this cap prevents power spikes and when mounted far from the power pins, causes the PCB trace wires to become inductors and the effect of the cap to smooth the power is reduced. So lay the cap on the bottom of the board between the two sets of power pins and solder to teh traces there for best effect. Prefereably the kit would ship with two and those would be soldered directly across each power and ground pin set, on the chip but my kits only included one cap.

[Dream Dragon]

Interesting project.