Loadcell sensor 24 bit ADC - HX711

This module uses 24 high precision A/D converter chip HX711. It is a specially designed for the high precision electronic scale design, with two analog input channel, the internal integration of 128 times the programmable gain amplifier. The input circuit can be configured to provide a bridge type pressure bridge (such as pressure, weighing sensor mode), is of high precision, low cost is an ideal sampling front-end module. 

Specifications

• Differential input voltage: ±40mV (Full-scale differential input voltage is ± 40mV)
• Data accuracy: 24 bit (24 bit A / D converter chip.)
• Refresh frequency: 10/80 Hz
• Operating Voltage: 2.7V to 5VDC
• Operating current: <10 mA
• Size: 24x16mm 

Board Schematic

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Sample Code

sbit AD_DATA_PIN = P1^5; // Pin mapping of microcontroller
sbit AD_SCK_PIN = P0^0; // Pin mapping of microcontroller

unsigned long ReadCount(void)
{
	unsigned long Count;
	unsigned char i;
	AD_SCK_PIN=0; 
	Count=0;
	while(AD_DATA_PIN); 
	for (i=0;i<24;i++)
	{
		AD_SCK_PIN=1;
		Count=Count<<1;
		AD_SCK_PIN=0;
		if(AD_DATA_PIN) Count++;
	}
	AD_SCK_PIN=1;
	Count=Count^0x800000;
	AD_SCK_PIN=0;
	return(Count);
}

Related Links

• Sparkfun Guide
• Instructable
• Rasberry Pi Interfacing Code
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• Arduino Code