Hello. I am a beginner. I want to work with a load cell through an amplifier, and I have seen that you need to connect the amplifier to digital pins. I don't understand that, since I know that digital pins are binary, so how can information such as weight can be transferred like that? My logic says that it must go to the analog pins, 0-1023...?
Can someone explain that please?
Thanks
What sort of signal or value does the amplifier output and at what voltage ?
Please provide a link to the amplifier that you are referring to
Sorry I thought these were a universal standard components for basic scales.
I'm using a load cell and the HX711 amplifier, as shown in the pic. Thanks
The HX711 and its associated library do all the hard work and allow the library to return a float value using the getData() function, hence the use of digital pins for data and clock
This provides better accuracy and a greater range than if the scales returned a simple 0-1023 value
Ok thank you.
Could explain or refer me to an explanation to this function and mechanism of work of digital pins? As far as I know they can only receive HIGH\LOW.
Yes, but they can receive a series of 0's and 1's and assemble the received bits into bytes. That is how a serial interface works.
The interface can put a 0 or 1 on the data line (DT) then set the state of the clock line (SCK) to indicate that a valid bit is available to be read and so on until all the bits have been read into bytes to be used by the receiving program
Do some research on how an I2C interface works
The HX711 has an amplifier, an ADC and a digital interface in one chip. You can google "HX711 datasheet" for the detailed information about it.
Your close on understanding it. Analog is a signal that conveys information by its voltage or current level, a digital conveys information by being either on "1" or off "0". Usually on is above a certain value and off is below, anything in between is undefined. These 1's and 0's are grouped in bundles of 8 called bytes. A word is two bytes or 16 bits. This is relative common but there is nothing stating the sensor has to conform to that, that is the manufacturer's decision. The actual values of this vary with the various logic families. In your case the HX711 reads the analog value from the sensor and converts it to a digital signal. This keeps your design much easier as analog is more sensitive to and subject to electrical noise. the HX11 then converts the analog signal to a digital signal is a predefined format and sends it serially to the Arduino. The pattern of the data is specific to the module and the weight on it but there is a protocol that defines what the patterns indicate, The Arduino reads this digital data and converts it whatever you want. Sparkfun has some good reading at this link: Analog vs. Digital - SparkFun Learn
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