The SparkFun OpenScale is a simple-to-use, open-source solution for measuring weight and temperature. It has the ability to read multiple types of load cells and offers a simple-to-use serial menu to configure calibration value, sample rate, time stamp, and units of precision.

Simply attach a four-wire or five-wire load cell of any capacity, plug the OpenScale into a USB port, open a terminal window at 9,600bps, and you’ll immediately see mass readings. The SparkFun OpenScale will enable you to turn a load cell or four load sensors in a Wheatstone bridge configuration into the DIY weigh scale for your application.

Onboard the SparkFun OpenScale is the ATmega328P microcontroller, for addressing your communications needs and transferring your data to a serial terminal or to a data logger such as the OpenLog, an FT231 with mini USB, for USB to serial connection; the HX711, a 24-bit ADC for weighing scales; and the TMP102, for recording the ambient temperature of your system. The OpenScale communicates at a TTL level of 9,600bps 8-N-1 by default and possesses a baud rate configurable from 1,200bps to 1,000,000bps.

The OpenScale was designed for projects and applications where the load was static (like the beehive in front of SparkFun HQ) or where constant readings are needed without user intervention (for example, on a conveyor belt system). A load cell with an equipped OpenScale can remain in place for months without needing user interaction!

Features:

1. Selectable 10SPS or 80SPS Output Data Rate
2. Local & External Temperature Sensors
3. Fixed & Adjustable Gain

Package Includes:

1 x SparkFun OpenScale

A strain gauge is a device used to measure strain on an object. This strain gauge module uses the strain gauge BF350-3AA, it has an onboard amplifier and potentiometer to adjust the measured results

A Strain gauge is a sensor whose resistance varies with applied force; It converts force, pressure, tension, weight, etc., into a change in electrical resistance which can then be measured

A strain gauge works on the principle of electrical conductance and its dependence on the conductor’s geometry. Whenever a conductor is stretched within the limits of its elasticity, it doesn’t break but, gets narrower and longer.

Features:

1. Two tubes reverse protection ~ (to prevent the power supply from connected to the back)
2. On board with a blue LED power indicator
3. Analog output
4. The higher the bending degree, the higher the output voltage
5. Zero potentiometer
6. Can be used to adjust the output voltage of the starting voltage

Specifications: 

1. Voltage: 5V
2. Model: BF350-3AA/1.5AA
3. Sensitivity factor: 2
4. Strain limit: 2%
5. Grid wire: longxwide2x3.5mm
6. Base size: long the width of 5X4.5mm
7. Base material: modified phenolic substrate
8. Resistance: 350 ohms
9. Fatigue life: >10000000 times
10. Flux: ordinary rosin solder

Packages Includes: 

1 x Strain Gauge Bending Sensor Module

FSR series is a force sensing resistor that exhibits the unique characteristic of dynamic resistance related to the amount of applied force. Typical force-sensing resistors are characterized for HumanMachine Interface (HMI) or Machine-Machine Interface (MMI) applications with a sensing range from circa 20g to 5Kg. Specific device characteristics will depend on the size, shape, and materials used in construction. Force-sensing resistors are intended for applications where a delta in applied force is to be detected. They are not intended for high accuracy or specific weight measurement applications.

Note: Images shown may vary from actual product in terms of branding and labeling.

Specifications and Features:

1. 39.70 x 39.70mm active area
2. Standard square format
3. Connector housing (female, equivalent to Nicomatic 14106-12 and OF02)

1 x OHMITE FSR Series 20 g to 5 kg Force Sensitive Resistor Sensor with Square Connector Housing

The FlexiForce Prototyping Kit allows engineers and designers the freedom to plug their preferred circuit module(s), easily make sensitivity adjustments, and gain confidence in how a FlexiForce sensor will behave in their prototype. The open-source nature of this kit makes for a more efficient progression to field-testing and the final embedded design.

Advantages:

1. Sensitivity adjustment made programable via reference voltage. An onboard jumper easily selects the applied voltage.
2. Resistor/capacitor values are easy to swap out.
3. Be more confident in FlexiForce sensor performance in your proof-of-concept and prototype.
4. See instant feedback of sensor performance under different loading actuators and interfacing materials.

Features:

1. The small and affordable kit saves engineers and designers the effort of building circuitry and other components for their FlexiForce-embedded proof-of-concept or prototype.
2. Interchangeable analog circuit modules allow users to test the functionality of their FlexiForce sensors with ease.
3. The open-source software interface allows users to control loading, record sensor data, adjust sensitivity, and calibrate the sensor.

Package Includes:

1 x FlexiForce Prototyping Kit FLXPK1

This S-Type load cell can convert up to 200kg of pressure (force) into an electrical signal. Each load cell can detect changes in electrical resistance as a result of the strain (pressure or force) applied to the form. This gauge can be used to measure how heavy an object is, if its weight changes over time, or simply to detect the presence of an object by detecting strain or load applied to a surface.

Each straight bar load cell is made of alloy steel and can hold up to 200 kg. In these load cells, four strain gauges are coupled in a Wheatstone bridge design. On the connection wiring, red denotes E+, green denotes O+, black denotes E-, and white denotes O-. Furthermore, these load cells have an IP66 protection certification and two M4 and two M5 sized through-holes for attachment.

It has Four lead wires which can be connected to  HX711 A/D Pressure Sensor.  It is easy to use with driving voltage 5-10V and produces the output voltage as per the force changes over it.

Connection Diagram with Arduino via HX711:

Applications:

Electronic weighing, weighing, and other power measurements, weighing the industrial automation measurement and control system.

Package Includes:

1 x Pull Tension YZC-516C Pressure Sensor 200KG

The DT series of piezo film sensor elements are rectangular elements of the piezo film with silver ink screen
printed electrodes. They are available in a variety of different sizes and thicknesses. The DT film element produces more than 10 millivolts per microstrain, about 60 dB higher than the voltage output of a foil strain gauge. The capacitance is proportional to the area and inversely proportional to the thickness of the element.

Features:

1. Piezoelectric film sensor without lead attachments
2.  Silver ink electrode
3.  Available in different sizes and thicknesses
4.  Great for making your own senso

Specifications:

1. Thin Piezo polymer w/ high piezo activity
2. Flexible silver ink metallization
3.  Min. input impedance: 1 MΩ,
4. Recommended Impedance: 10 MΩ
5.  Output voltage: mV to 100s of volts
6.  Operating temp: -40 to 60°C
7. Capacitor: 1.38 nf

Package Includes:

1 x PIEZOELECTRIC SENSOR, VOLTAGE, 1.38NF