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Mini Weight Unit (HX711)

Mini Weight Unit (HX711)

Description
WEIGHT intergrates an 24 bits A/D chip HX711 that is specifically designed for electronic weighing device.
The input multiplexer selects either Channel A or B differential input to the low-noise programmable gain amplifier (PGA). Channel A can be programmed with a gain of 128 or 64, corresponding to a full-scale differential input voltage of ±20mV or ±40mV respectively, when a 5V supply is connected to AVDD analog power supply pin. Channel B has a fixed gain of 32. There is no programming needed for the internal registers. All controls to the HX711 are through the pins.
In the test, we have this Unit channel A to connect a pressure sensor. Then use M5Core screen to display the weight data.
Product Features
  • Two selectable differential input channels
  • On-chip active low noise PGA with selectable gain of 32, 64 and 128
  • On-chip power supply regulator for load-cell and ADC analog power supply
  • On-chip oscillator requiring no external component with optional external crystal
  • On-chip power-on-reset
  • Simple digital control and serial interface: pin-driven controls, no programming needed
  • Selectable 10SPS or 80SPS output data rate
  • Simultaneous 50 and 60Hz supply rejection
  • Current consumption including on-chip analog power supply regulator: normal operation < 1.5mA, power down < 1uA
  • Operation supply voltage range: 2.6 ~ 5.5V
  • Operation temperature range: -40 ~ +85℃
  • 16 pin SOP-16 package
  • Program Platform: Arduino, UIFlow(Blockly, Python)
  • Two Lego-compatible holes
Kit includes
  • 1x WEIGHT Unit
  • 1x Grove Cable
Application
  • Micro weight meter
  • Kitchen Scale
Documents
Learn
Example
1. Arduino IDE
We used a pressure sensor(10kg) in this experiment. (Unit: gram)
To get complete code, please click here。 
/*   This Unit connects to GRVOE B on M5Core. */  #include <M5Stack.h> #include "hx711.h"  HX711 scale(36, 26);// GROVE B  void setup() {   M5.begin();   M5.Lcd.clear(BLACK);   M5.Lcd.setTextSize(2);   M5.Lcd.setTextColor(YELLOW);   M5.Lcd.setCursor(50, 10);   M5.Lcd.print("UNIT_WEIGHT EXAMPLE\n");   M5.Lcd.setCursor(15, 50);   M5.Lcd.print("Connect Unit to GROVE B");   Serial.begin(115200);    scale.setOffset(125184);   scale.setScale(67.4);    M5.Lcd.setCursor(0, 90);   M5.Lcd.print("The weight: "); }  void loop(){   // Serial.println(scale.averageValue());   float weight;   weight = ((float)((int)((scale.getGram()+0.005)*100)))/100;   // sprintf(&weight, "%0.2f", scale.getGram());   Serial.print("The weight: ");   Serial.print(weight);   M5.Lcd.fillRect(150, 90, 100, 20, BLACK);   M5.Lcd.setCursor(150, 90);   M5.Lcd.print(weight);   Serial.println(" g");   delay(100); }
2. UIFlow
To get complete code, please click here。

More information
Schematic

Pinmap
If WEIGHT was connected to GROVE AM5Core(GROVE A)GPIO22GPIO215VGNDWEIGHT UnitDATA Pin (DAT)CLOCK Pin (CLK)5VGND
If WEIGHT was connected to GROVE BM5Core(GROVE B)GPIO36GPIO265VGNDWEIGHT UnitDATA Pin (DAT)CLOCK Pin (CLK)5VGND
If WEIGHT was connected to GROVE CM5Core(GROVE C)GPIO16GPIO175VGNDWEIGHT UnitDATA Pin (DAT)CLOCK Pin (CLK)5VGND 

The Mini Weight Unit (HX711) appears in the following collections:

SKU M5-U030
by Little Bird