Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
8 years ago

Altera DE2 read input from a weight sensor's HX711 ADC

question:

Would it be possible and feasible for a beginner to use Verilog HDL and an Altera DE2 board to read input from a weight sensor's HX711 ADC (see below), and if so:

  • What kind of data am I reading?

  • Where/how do I connect it?

(I suppose that "is it possible/feasible for a beginner" could be too vague for this forum, but the two bullet points above are the real question.)

Alternatively, if it's not possible/feasible, what would I need to look for in an Arduino microcontroller to use the HX711, in terms of minimum requirements (for the cheapest possible solution)? I believe I could connect an Arduino board to the DE2 via USB (though I wouldn't know what to do with that either).

context:

I'm a computer science student, working on a final project for a basic (and very rushed) hardware course. I have little to no prior experience with electrical engineering.

For my project, I'm required to either use Verilog HDL or MIPS Assembly Language -- and I'm far more familiar with Verilog at this point.

I am using an Altera DE2 educational board (with Cyclone® II 2C35 FPGA):

https://www.altera.com/solutions/partners/partner-profile/terasic-inc-/board/altera-de2-115-development-and-education-board.html

https://alteraforum.com/forum/attachment.php?attachmentid=14688&stc=1

For my project, I'm trying to build a system that can detect the amount of liquid in a container, can be calibrated for any similarly-sized container, and then can (theoretically) fill the cup to the appropriate level, or at least calculate the amount of liquid needed to fill it.

I could only find one load/weight sensor in a local shop and I unfortunately don't have time to wait for online delivery, so it seems to be my only option. It is "Arduino compatible" and uses an HX711 amplifier/ADC datasheet: http://www.kynix.com/uploadfiles/pdf8827/hx711.pdf

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    8 years ago

    Hello Lingyueqing,

    The fastest and simplest way to go is use VHDL.

    If you know Verilog, VHDL is just a matter of syntax.

    If you want to go the processor way, then you will have to learn how to implement a soft processor on your board and on top of this ARM assembly language.

    What your chances are depends on your experience and drive.

    Best regards,

    Johi.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    8 years ago

    I would think you could completely skip using the Arduino and connect the HX711 directly to your DE2 board via the latter GPIO pins, making

    sure that the DE2 and HX711 are using the same voltage level. Then program the Verilog in the Cyclone FPGA to calibrate and read the HX711,

    perform the needed computations in Verilog, and display the output on the 7 segment display of the DE2. The datasheet for the HX711 shows

    that it is a simple GPIO serial interface. You would need one or more load cells, in addition to the HX711, to make a complete system.

    I would ask somebody locally to help you out, like a graduate teaching assistant, a fellow student, or a professor. Most graduate students

    are happy to help other students.