Simple Dark Detect LED Robot's Flashlight
by syfrog in Circuits > Sensors
1653 Views, 35 Favorites, 0 Comments
Simple Dark Detect LED Robot's Flashlight
![14, 17:12.jpg](/proxy/?url=https://content.instructables.com/FIB/QUVE/HWCJHZSS/FIBQUVEHWCJHZSS.jpg&filename=14, 17:12.jpg)
I'm going to show you a simple, adjustable light sensor circuit that activates in low light.
Light sensing circuits are versatile and simple enough for beginners to build but have many useful applications.
The circuit I am presenting is to be used as a headlamp for my robot A3-8D (anyone in manufacturing may get joke.) This lamp will automatically turn on when the robot enters a dark room. This will save precious microprocessor inputs and outputs.
Light sensing circuits are versatile and simple enough for beginners to build but have many useful applications.
The circuit I am presenting is to be used as a headlamp for my robot A3-8D (anyone in manufacturing may get joke.) This lamp will automatically turn on when the robot enters a dark room. This will save precious microprocessor inputs and outputs.
The Schematic and the Parts
![14, 17:12.jpg](/proxy/?url=https://content.instructables.com/FGC/WEZY/HWCJHZST/FGCWEZYHWCJHZST.jpg&filename=14, 17:12.jpg)
The schematic is daily simple and there are not too many part required
Parts you will need:
- LEDs from a dollar store flashlight
- 1 x Transistor 2N4401
- 1 x Photoresistor
- 1 x 100 ohm resistor
- 1 x 100K ohm Variable-resistor
- Breadboard and hookup wire
- Perfboard, wire and soldering materials
Parts you will need:
- LEDs from a dollar store flashlight
- 1 x Transistor 2N4401
- 1 x Photoresistor
- 1 x 100 ohm resistor
- 1 x 100K ohm Variable-resistor
- Breadboard and hookup wire
- Perfboard, wire and soldering materials
Prototype Before Soldering
![14, 22:36.jpg](/proxy/?url=https://content.instructables.com/FBQ/Y9TE/HRCJZPFY/FBQY9TEHRCJZPFY.jpg&filename=14, 22:36.jpg)
![14, 22:36.jpg](/proxy/?url=https://content.instructables.com/F0A/M651/HRCJZPFW/F0AM651HRCJZPFW.jpg&filename=14, 22:36.jpg)
Even a simple circuit like this I take the time to layout on a board board and test before soldering. It's better to find you have a bad component or bad idea here than once it is on the CB. Desoldering is a pain.
I soldered some solid core leads on my led package to make it easier to breadboard.
I soldered some solid core leads on my led package to make it easier to breadboard.
Solder It Up and Cable It
![14, 17:12.jpg](/proxy/?url=https://content.instructables.com/F53/LZDV/HWCJHZSR/F53LZDVHWCJHZSR.jpg&filename=14, 17:12.jpg)
![14, 17:12.jpg](/proxy/?url=https://content.instructables.com/FPN/7191/HWCJHZSU/FPN7191HWCJHZSU.jpg&filename=14, 17:12.jpg)
![14, 17:12.jpg](/proxy/?url=https://content.instructables.com/FSH/EA46/HWCJHZSV/FSHEA46HWCJHZSV.jpg&filename=14, 17:12.jpg)
![14, 22:36.jpg](/proxy/?url=https://content.instructables.com/FX7/CIZD/HRCJZPFZ/FX7CIZDHRCJZPFZ.jpg&filename=14, 22:36.jpg)
I laid out my board so that the POT is facing out the direction of the lamp. When this is placed behind the skin of my robot I can have an access hole for adjusting the ON sensitivity without removing any panels.
Run 2 wires to the board for power and ground. I will be powering this with 5vdc.
Run 2 wires to the board for power and ground. I will be powering this with 5vdc.
Mounted and Tested
![14, 17:12.jpg](/proxy/?url=https://content.instructables.com/FM1/Y3ZW/HWCJHZSX/FM1Y3ZWHWCJHZSX.jpg&filename=14, 17:12.jpg)
![14, 17:12.jpg](/proxy/?url=https://content.instructables.com/F95/2DRD/HWCJHZSW/F952DRDHWCJHZSW.jpg&filename=14, 17:12.jpg)
This the Lamp mounted in the robot skin of A3-8D. The lamp works great too bad the robot is not autonomous yet.
He is pretty bare bones so far with only a USB power charging port and Bluetooth speaker system and a few sound sensors. I will share this circuit as soon as I can get it wrote up.
Thanks
He is pretty bare bones so far with only a USB power charging port and Bluetooth speaker system and a few sound sensors. I will share this circuit as soon as I can get it wrote up.
Thanks