Load cell and amplifier question

Sensors Force & Weight
1

Hey guys

My question relates to the Hx711 amp and the 10kg load cell (tal220)

My question is in wiring I’m confused on how it works and I’m needing clarification

I have a 5v supply and ground available to power the unit but what I need is a 0v to 5v output to input into my hardware

Can anyone draw me a simple diagram to depict this

I was hoping that the output voltage would be a linear scale from 0v being 0kg weight and 5v being 10kg weight is this correct

Any help would be amazing

Kind regards

Mathew T

2

Have you taken a look at the [Hookup Guide. That was extremely useful. I’ve used that several times with good success ([ex1, [ex2).](A Simpler Weight Scale | Electronics Forum (Circuits, Projects and Microcontrollers))](Expanding on Simple Weight Scale | Electronics Forum (Circuits, Projects and Microcontrollers))](https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide)

3

I read through it but the output I don’t understand the power side and the load cell I get but It doesn’t list an output voltage range

4

The Hx711 does not have an analog output. It is designed to connect to a processor using I2C digital communications.

For power, Vcc connects to +5V and GND to ground. If your processor runs on 5V, Vdd should also be connected to 5V. If your processor runs on 3.3V, Vdd should be connected to 3.3V. This is all shown in the schematic at https://cdn.sparkfun.com/assets/f/5/5/b … d_Cell.pdf

/mike

5

When it’s all said and done, the quickest and easiest solution for getting an analog output might be buying an off the shelf device:

[Example amplifier

These instruments are sometimes called load cell or strain gauge transmitters.](http://swann-associates.com/load-cell-amplifiers/icas-icah-strain-gauge-or-load-cell-embedded-analog-amplifier/)

6

brow:
When it’s all said and done, the quickest and easiest solution for getting an analog output might be buying an off the shelf device:

[Example amplifier
[/quote]
Right you are. And this is precisely what the HX711 is. Perhaps the difference is on the resolution and quality of the amp; but the HX711 does the amplification, conditioning, ADC, and averaging function (which otherwise would have to be done outside the single analog amp (i.e. at some point or other, you will still need the other functions to get the desired results - unless all one cares for is a raw analog voltage).](http://swann-associates.com/load-cell-amplifiers/icas-icah-strain-gauge-or-load-cell-embedded-analog-amplifier/)

7

MT performance:
I read through it but the output I don’t understand the power side and the load cell I get but It doesn’t list an output voltage range

You connect it exactly as in any of the examples I pointed to (one of which SFE already went through great detail in describing). The HX711 is an analog amplifier, with programmable gain, with some conditioning built-in, with an analog-to-digital converter built-in; so that you can go from raw voltage output (from TAL220 load cell) to a digital output that can be read by a digital device (e.g. MCU, PLC, rPI, FPGA, etc.). The assumption from you using the HX711 with the TAL220 is that you are trying to read the load cell (i.e. TAL220) with some sort of digital device. Perhaps you are trying to do something different; cause the hookup could not get much easier than the HX711 Hookup Guide from SFE.

8

Perhaps the pictorial stuff on the guide is a bit confusing. If that is the case, maybe this can help a bit.

From the [HX711 Hookup Guide pay attention to the table that reads (forgive the poor attempt at table formatting):

Wheatstone Bridge Node … “Typical” Wire Color

Excitation+ (E+) or VCC … RED

Excitation- (E-) or GND … BLACK or YELLOW

Output+ (O+), Signal+ (S+), or Amplifier+ (A+) … WHITE

O-, S-, or A- … GREEN or BLUE

You can then look at this other [guide to get a better description of the pinouts.

You are looking at the “Load Cell” section of the picture (ignore the “Temp” and “Load Sensor Combinator”).](https://learn.sparkfun.com/tutorials/openscale-applications-and-hookup-guide#hardware-features)](https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide#hardware-hookup-)

9

languer:
Right you are. And this is precisely what the HX711 is. Perhaps the difference is on the resolution and quality of the amp; but the HX711 does the amplification, conditioning, ADC, and averaging function (which otherwise would have to be done outside the single analog amp (i.e. at some point or other, you will still need the other functions to get the desired results - unless all one cares for is a raw analog voltage).

OP is looking for a 0-5 volt analog signal that is proportional to the load. Analog outputs are very common for PLC inputs in automated environments, though a 4-20 mA system is probably more typical.

Edit: 5 volts, not 10.