Hx711 the hx711 is a 24 bit analog to digital converter adc.
Load cell adc calculation.
Figure 5 is a block diagram of a reference design a weigh scale system evaluation board designed at analog devices.
From equation 42 and supplying the values determined for a 2mv v sensitivity and 10kg load cell you should be able to achieve better than 1g resolution using the settings shown in this application.
With an onboard low noise amplifier onboard oscillator precision third order 24 bit delta sigma modulator and bridge power switch the ads1231 provides a complete front end solution for bridge sensor applications including weigh scales strain gauges and load cells.
Strain gauge load cells.
The ads1231 is a precision 24 bit analog to digital converter adc.
Hx711 is a precision 24 bit analog to digital converter adc designed for weigh scales and industrial control applications to interface directly with a bridge sensor load cell strain guages.
A conversion scale graphic for each load and millivolt output range combination entered is also displayed below the calculated values.
It interface with simple digital i o to any controller.
If you are working with a standard 2mv v load cell and a 10v excitation current this will give you a full scale input range of 20mv at the ad7730.
While on the left side we have e e a a b and b.
And lastly though there are many other less common load cell set ups there is a strain gauge load cell which is a mechanical element of which the force is being sensed by the deformation of a or several strain gauge s on the element.
Strain gauge load cells are by far the most common type of load cell based weighing system in 2010.
As you can see on the right side we have ground dt sck and vcc.
If you were using a 5v excitation current with the same load cell your full scale would be 10mv and therefore you would be effectively loosing one bit of resolution.
Which has an amplifier which gives maximum gain of 128 as per the datasheet.
The load cell can be directly interfaced to this adc.
This load cell millivolt output calculator provides a way to determine the output reading and range from the applied load load cell range and strain gauge output characteristics.
It consists of an ad7799 adc controlled by an aduc847 microcontroller.