TVbNull

From Null Space Labs

Based on the TV B Gone by Mitch Altman and Ladyada

PARTS

[LED3] x1
[R1] x1
[BATH1] x1
[BATT1] x1
[R2] x1
[R3, R4] x2
[C1] x1
[C2] x1
[C3] x1
[Y1] x1
[IC1] x1
[LED1, LED2] x2
[Q2] x1
[Q1] x1
[Switch1] X1 (from SparkFun)

CODE

Available on the NSL SVN

Under "/032/TV_Nullifier/firmware v1.2/tvbgone.hex"

ATtiny85

Fuses

LOW 0xFD
HIGH 0xDe

BUILD INSTRUCTIONS

So in a few easy steps, you too can have a TVbNull.

Here's the board layout:

1) Place the ATMEL ATTINY85V: The dot on the chip indicates chip orientation and lines up with the circle on the board.

3) Add Resonator:

4) **IMPORTANT** - Program the chip now!!! The chips are pre-programed.

5) Add R2 and R3, the 10KOhm resistors.

5) Add C1, the 0.1uF (or 100nf) capacitor.

6) Add R1, the 1KOhm 1206 resistor. If building a kit, this would be the 860Ohm resistor.

7) Next add the LED. Before placing the LED it's important to test the polarity since orientation matters for this part. You can test it using a multimeter. Turn the mulitmeter on to the diode setting, as shown below. Take the two leads and place them on the ends of the LED. The purpose of this is to figure out which way the current will flow through the LED, since, like regular diodes, current can only flow in one direction. Once the LED lights up, you will have figured out which side of the LED is the anode (the + side) and which is the cathode (the - side).

8) You will want to line up the cathode of the LED with the 3 little dots of the board. The cathode is usually marked with a little green speck. It's important to always check at least 1 LED from a batch since the marking on the LED does change depending on the manufacturer.

9) Next you'll want to add the PNP transistor (BC857AT115)

10) Add R4, the 1KOhm 0805 resistor.

11) Add the NPN transistor (FMB2222A) NOTE: Dot in front of the '1' denotes orientation, as shown in the picture below.

12) Add press switch

13) Add C2, the 10uF capacitor. The stripe on the capacitor should line up with the arc on the board.

14) Add C3, the 100uF capacitor. Again, the stripe on the capacitor should line up with the arc on the board.

15) Now place the infrared LEDs. The cathode (-) side of the LED is the larger part inside and the anode (+) side has slightly longer leads. You'll need to cut them to length.

16) When putting on the battery holder, make sure to line up the notch in the board with the protrusion on the holder.

17) Make sure to clean of the board with Flux Remover, rinse off under very hot water and dry it thoroughly. Put the battery in and you've got a working board!