BedLed

Video

In this video you see the switches I've chosen. These are 5V metal momentary switches along with a socket.

These switches have 5 pins, with the following colors attached on the socket:

1. Red - LED Source (+)
2. Black - LED Ground (-)
3. White - Normally Open (NO)
4. Green - Common (C)
5. Blue - Normally Closed (NC)

When the button is released NC is connected to C and NO is not connected. When the button is pressed NO is connected to C and NC is not connected.

I have connected + to 5V, - to NC, NO to my button pin, C to ground. So when the button is not pressed, current flows from - through NC, to C, to ground, connecting the LED - to ground. When the button is pressed, the LED flow is interrupted and the LED turns of (signaling the user a confirmation of the pressing). The button pin on the ATtiny is then connected through NO to ground.

Schema

Also available on Aisler

Parts

• D1 - Skottky diode (20V, 3A)
• C1 - 16V, 0.33µF
• C2 - 5V, 0.1µF
• IC2 - LM7805
• Q1 - IRFZ44N
• U1 - ATtiny85
• J1 - 2 pin header with jumper
• Power supply socket
• Terminals for button and LED connections
• Buttons

Optional:

• J2 - 2x3 pin ICSP header (optional)
• RF expansion (e.g. 433 MHz receiver)
• Reset button (with 2-pin connector)

Connector pins:

• J1, 1 - Pin 6 (PB1, MISO)
• J1, 2 - Q1 gate

J1 - Jumper options:

• 1-2: Pin 6 (PB1) connected to Q1 gate

J2 - ICSP

• 1: MISO
• 2: VCC
• 3: SCK
• 4: MOSI
• 5: RESET
• 6: GND

J3 - RF expansion

• 1: GND
• 2: NC
• 3: Data
• 4: VCC

A serial connection with status/debug info (at 9600 baud) is available on J2-3 (SCK) which is connected to U1-PB2.

The optional reset button can be connected to J2-5,6. Computer power/reset switches are very suitable for this.

Flashing

To prevent interruptions and blinking the LED strip during flashing:

• Disconnect the MOSFET by removing the jumper on J1 (freeing pin 6 - MISO)
• Remove the RF expansion (freeing pin 5 - MOSI)

Version 2

After years of use I've made some software improvements in version 2.

The KlikAaanKlikUit module and code is removed. I've never managed to get a remote to work from more than half a meter away and have given up on it.

In the dark we sometimes would like to turn on the light, but really dimm. To enable this I have added an even dimmer setting (1/255 PWM). Additionally if the button is held while turning on, it turns on with the dimmest option.

To quickly turn on the brightest a simple double click will suffice.

Additional clicks immediately after turning on will cycle through other modes.