A digital scale comprises a load cell transducer, signal conditioner, and microcontroller; they all work to measure of weight and size of an object to give a reliable value in a specific S.I unit. Upon purchasing this device, an individual gets a guide datasheet where they can set up the scale without difficulty.
Digital scales are applicable in our day-to-day lives; they come in handy at home and in production sectors. One can also apply it in hospital setups by measuring a patient’s weight. The composition of the weighing scale includes as follows;
- Load cell transducer
This component senses the weight applied to the machine producing an electrical output signal proportioning to the weight involved. There are various types of load cells, but not all are transducers. Load cell transducers are sensors.
The sensor detects physical features such as weights and then transforms them into a physical parameter. Moreover, the transducer senses the physical part but converts it to an electrical output. Load cells use hydraulic load, strain gauge, and pneumatic load cells.
- Signal conditioner
A circuit device plays two significant roles; it facilitates amplification of load cell output voltage and filters input and output signals. Since the output of a load cell is very minute, often measured in mV signal condition is very critical in making it at a more functional level. The Signal conditioner filters noise and electromagnetic interference that might interfere with the amplified signals.
The microcontroller is a central processing unit in a digital weighing scale. It reads the digital clocked pulses from the signal conditioner to retrieve the data for determining the weight value displayed. The microcontroller then computes the weight obtained and displays it on the LCD screen.
How to build a digital weighing scale
- Hardware set up
The load cell has four wires, and these wires have different characteristics depending on the load cell’s datasheet. The red wire is the positive power supply, the black wire is the positive output, the white wire is the ground power supply, and the green is the negative output.
An extra wire might be blue or yellow, and the ground wire is connected to the power supply ground. While purchasing a digital scale, you should request the datasheet to aid you in securing the device by yourself.
- Load cell to the amplifier
While connecting the load cell to the amplifier, it should follow the following sequence;
Red wire and white wire for positive and negative supply, respectively, followed by green and black for negative and positive outputs.
- Amplifier and microcontroller connection
The H*711 connects to the microcontroller unit in this step.
- The Code
Upon coupling the components of the digital scale system, one then must upload the program codes to the microcontroller unit. The process has two features the calibration code and the weighing code.
Calibration code plays a role in calibrating the load cell transducer, in performing configuration of the output obtained from the load cell to give an exact weight value at a particular S.I unit. The weighing code uploads the values receive during calibration in the microcontroller unit.
This article provides information on the digital scale’s components, the device’s functions in measuring weights during its applications, and the process of setting up the scale.