Featured Product: Stribe1
Lighted Touch Strip

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Stribe1 : Instructions - Curious Inventor

Kits: Stribe1

--- building instructions ---

The parts: (first check to make sure you got everything, let us know if not!)

  • U1, U2: MAX7221 (spec), SPI controlled 64 LED Driver
  • (2) 24 pos. sockets for U1 and U2
  • C1: 10 uF electrolytic capacitor
  • C2: .1uF ceramic capacitor
  • J1: 2x8 male header to select which analog line to transmit on
  • P1: 2x8 male header for ribbon cable connection
  • (1) 170mm SoftPots
  • (14) 20 pos. sockets
  • (14) 10 LED Bargraphs
  • 6 inches of 16 conductor ribbon cable
  • (2) IDC ribbon cable connectors, 16 pos.
  • (1) Jumper / Shunt for choosing an analog channel
  • R1, R2: 47k 1/8W resistor (current limiting / brightness resistor for each MAX7221)
  • R3: 10k 1/8W resistor (pull-down resistor to zero the softpots when not touched)
  • acrylic top and bottom
  • assorted screws and hardware

1. Recommend Tools and Supplies:
  • Soldering Iron and Solder:

    For solder, we recommend .015, .02 or .031" diameter (smaller is easier, but you can get away with .03" for these parts), rosin cored flux, tin-lead solder, either 63/37 or 60/40, whatever's cheaper. See our soldering guide for explanations. Lead-free solder is a little bit harder to use since it "wets" metal somewhat slower and has a slightly higher melting point. If your kit has sat on the shelf for a while (a year), some steel wool or a pink eraser is useful to remove oxidation from the components and board before starting.

  • Needle Nose Pliers: Used to clinch or bend component leads and helpful for pulling out components when fixing mistakes.
  • Flush Cutters: Used to trim leads close ("flush") to the board.
  • Solder Wick: Used to remove bridges between pins on surface mount chips. A popular technique is to flood the leads with solder until everything is bridged together, and then go back with wick to remove bridges. Surface tension will retain enough solder to keep a connection.
  • Clamp: A table top will be fine for most of the job, but a clamp can be handy, especially when removing components.
  • Multimeter: To check your work.
  • Wire Strippers:
  • Small jeweler's phillips screwdriver
2. Soldering the Sockets:

First tack the corners of 4 corner sockets (2 10x2 and 2 12x2) and lay on a table to make sure they're flat. The key with all the sockets is to make sure they're flat before soldering all the pins.

Now we recommend inserting the rest of the sockets, carefully turning it over so that none of them fall out, and tacking their corners in place. Again, check to make sure everything is flat, then solder away!

3. Adding the resistors and capacitors:

Make sure the longer lead of the electrolytic cap (cylindrical) goes in the positive hole. Also, the picture doesn't show it too well, but leave a little air between the black cap and the pcb. This will help it bend out of the way slightly when the IDC connector is connected.

4. Add the (2) 2x8 male headers to P1 and J1:
Also, stick on the jumper / shunt on one of the rows of J1 to select that as the analog channel on the ribbon cable. See the Connecting and Usage Guide for details on this. The 8 pins on the bottom of J1 are all connected to the middle pin of the softpot. The jumper routes this analog signal to one of the even numbered ribbon cable conductors.
5. Install LEDs and MAX7221s
6. Add Data Wire:

The ribbon cable caries all the necessary signal except the SPI Data line, or MOSI (master out slave in) line. This is because this signal gets daisy chained to each MAX7221, going in one side (P4) to the left MAX7221's datain, out its dataout, into the right MAX7221's datain, out its dataout to P5. To attach another Stribe1, you have to connect a wire from the fist Stribe1's P4 to the next Stribe1's P5.

7. Install the ribbon cable.

It's pretty tight spacing, you might have to bend the cap a little to get the IDC in place.

The next pictures show putting the touchstrip and acrylic on without the ribbon cable, but it's very difficult to fit the ribbon cable on once the softpot / touchstrip is soldered in place.

8. Attach the softpot / touchstrip to the acrylic.

Line up the edge of the softpot's adhesive edge before it necks into the blue connector with the bottom edge of the hole in the acrylic. Press down a little of the strip and then check to make sure the other end is centered. Then slowly press it down from the connector to the far end.

If you have to unstick it and start over, it's not the end of the world, but the more times you pull it up the less secure it will be, and the strip's signal will start to degrade a little, also.

Rub with a thumb nail to work out all the air bubbles.

9. Solder the SoftPot (attach ribbon cable first! --not shown in pic--)

Jiggle the softpot leads until they pop into place, then solder the other side.

10. Screw together the top and bottom acrlyic pieces.

Install the two shorter screws from the top of the pcb into the holes that are about a 1/4" from the end of the acrylic. Install the longer screws in the 4 corners, going through the pcb in the end. Use washers on the bottom side if included with your kit. There will be a gap between the holes in the pcb and the screws, but everything will be held in place from top-to-bottom pressure.