This project is about making portable luxmeter. It can be used in schools, where children can measure different kinds of light sources.
Functions:
1. measure intensity of light in lux.
2. calculate solar irradiation from lux to watts/m2 (factor 112)
3. charging battery using USB port
Total cost is around 13 $ without case. Luxmeter take 15 mA, so it will works long time on one Li-Ion battery.
Step 1: BOM
- For project you need this components(affiliate links, if you want to support me):
Arduino Pro Mini 5V
MAX44009
- Wide 0.045 Lux to 188,000 Lux Range
VCC = 1.7V to 3.6V () - ICC = 0.65µA Operating Current
- -40°C to +85°C Temperature Range
- Link
OLED display
- Diagonal Screen Size：0.96″
- Number of Pixels：128 x 64
- Color Depth：Monochrome (Yellow&Blue)
- Dimension：27.8 x27.3x 4.3 mm
- Working Voltage: 3.3~ 5V DC
- Power: 0.06W
- MaxViewing Angle: >160 Degree
- Duty：1/32Brightness ( cd/m2)：150 (Typ) @ 5V
- Interface： I2C
- Link
TP4056
- need USB to micro USB cable for charging
- input 5V
- Link
Li-Ion battery
- 3 – 4.2 Volts
- Link
18650 holder
Switch jumper
Cables and header
- female to female
- female and male header
- Link to cables
- Link to pin headers
Step 2: Circuit
You need of course 5V Arduino to power it with Li-Ion battery (4,2 V!)
Connections:
Arduino – MAX44009 (same for OLED display)
A4 – SDA
A5 – SCL
VCC – VIN
GND – GND
TP4056 – Arduino Pro Mini
OUT+ – VCC
Arduino – battery
VCC – plus terminal (max 5 V for Arduino 5V)
Arduino – switch jumper
GND – first switcher
TP4056 – switch jumper
OUT – – second switcher
Battery – switch jumper
minus terminal – first and second switcher
Read more: Portable Luxmeter
