HX711 Dual-Channel 24 Bit Precision A/D weight Pressure Sensor

A breakout board for the HX711 IC that makes it simple to read load cells for weight measurement is the HX711 Dual-Channel 24 Bit Precision A/D weight Pressure Sensor. You may read changes in the load cell’s resistance by attaching the module to your microcontroller, and after some calibration. It will be possible to obtain extremely precise weight measurements.

This is useful for simple presence detection, process control, or building your own industrial scale. The HX711 Weighing Sensor communicates via a two-wire interface (Clock and Data). The GPIO pins of any microcontroller should be compatible, and a number of libraries have been created to make reading data from the HX711 simple.

The HX711 is connected to load cells using a four-wire Wheatstone bridge. Typically, these are RED, BLK, WHT, GRN, and YLW in colour.

Every colour matches the standard load cell colour coding scheme as follows:

• Red (VCC or Excitement+).
• Black (GND or Excitement).
• White (Output+, Signal+, or Amplifier+).
• A-, S-, or O-green.
• (Shield) in yellow.

The YLW pin serves as an extra input that is used to ground and provide EMI (electromagnetic interference) shielding without connecting to the strain gauge. Please be aware that the colour coding of some load cells may differ.

Pinouts :

Analog Side :

1. E+: Excitation positive.
2. E-: Excitation negative.
3. A-: Channel A Negative Input.
4. A+: Channel A positive Input.
5. B-: Channel B Negative Input.
6. B+: Channel B positive Input.

Digital Side :

1. GND: 0V / Ground Power Connection.
2. DT: Data IO Connection.
3. SCK: Serial Clock Input.
4. VCC: Power Input.

Featuers & Specifications:

• 5–10 V is the recommended excitation voltage.
• Two differential input channels that can be selected.
• Active low noise PGA on-chip that may be adjusted to have a gain of 32, 64, or 128.
• ADC and load-cell analogue power supplies are powered by an on-chip power supply regulator.
• 80 Hz or 10 Hz output data rate selection.
• On-chip oscillator with an optional external crystal that doesn’t require any external components.
• Reset the power on the chip.
• Pin-driven controls with a serial interface are simple digital controls that don’t require programming.
• simultaneous supply rejection at 50 and 60 Hz.