Chopping Board Scales
| Projects | |
|---|---|
| Participants | Amx109 |
| Skills | |
| Status | Dead |
| Niche | Other |
| Purpose | Fun |
purpose: to build a big chopping board with inbuilt scale
Design
- Waterproof
- must display weight on surface of chopping board
- minimum 'maximum weight' of 5kg, with minimum 1g increments. pref 0.1g
- touch sensitive button
- on/tare
Electronics
Inspired by http://jdesbonnet.blogspot.co.uk/2010_10_01_archive.html
Materials
Chopping board:
- http://www.ikea.com/nl/nl/catalog/products/90115544/
- http://www.ikea.com/nl/nl/catalog/products/00233429/
Sensors
Specification:
Size: 34mmX34mm
Internal 1000 Ohm half-bridge strain gauge load cell, range is 50kg, half-bridge structure.
When measuring, the correct force is applied to the outer side of the strain E-shaped beam portion of the sensor (i.e., a strain gauge affixed to the middle, with a beam of white plastic cover arm) and the outside edges to form a shear force in the opposite direction, i.e., in the middle of strain beam bending necessary changes can occur under stress, strain beam side by another force can not have a barrier.
The sensor use the following three methods:
1, using a sensor with external resistors full bridge measurement range of a sensor range: 50kg. Higher requirements for external resistor
2, the use of only two full-bridge sensors measuring range is the range of the two sensors and: 50kgx2 = 100kg
3, the use of four full-bridge sensors measuring range is the range of four sensors and: 50kgx4 = 200kg
Wires
Red
Black
White
White->black=2k
White->Red=1k
Red->Black=1k
