Weight Scale using DAQ USB-6000 and HX711

[alsabri_71]

Hello, I want to make a Weigh Scale using load cell, HX711, and the DAQ to analyze the weight using LabVIEW software.

I have connected the load cell to HX711, and connected the HX711 pins as below:

VCC - 5 V supply

GND - ground

DT - Analog input pin

SCK - Digital output pin

When I make the programming, I use two DAQ assists, but it is not working well. I have merged the two signals, but still it is not displaying reliable number.

I used Arduino instead, it was quite easy. And now I am thinking of making it in Arduino, and display it in the LabVIEW.

How can I do it? Because I have used VISA, and didn't know how to continue the project.

[Bob_Schor · Accepted solution]

According to the HX711 Data Sheet, it appears to communicate with the user using digital lines (pins 11-15).  A USB 6000 is an analog input device -- you need a Digital I/O device.

Bob Schor 

[santo_13]

HX711 uses I2C protocol to return the data equivalent to the load. USB-6000 does not support I2C protocol.

Your options,

1. Connect HX711 to Arduino, install LINX, use the LINX I2C APIs to tell Arduino to read HX711
2. Buy a USB to I2C board like USB-8451, then use the 845x drivers to read/write I2C commands to read data from HX711
3. Find another load cell amplifier that outputs 0-5V instead of digital data, then you can use it with USB-6000
4. Find a load cell amplifier with a USB COM port interface like this one from Sparkfun

[GerdW]

Hi,

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@santo_13 wrote:

Your options,

1. Connect HX711 to Arduino, install LINX, use the LINX I2C APIs to tell Arduino to read HX711

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1b: Connect the HX711 to an Arduino, use the Arduino IDE to communicate with that sensor and use the (virtual) COM port of the Arduino to talk to your host computer with LabVIEW using plain VISA functions… (Will be very easy when there are libraries for Arduino supporting that kind of sensor!)

[alsabri_71]

Thank you bro for helping.

I have already made a weigh scale script that reads the voltage reading and convert it to weight reading by using a calibration factor, but I just need to view the readings that I see (in Serial Monitor) to the LabVIEW.

I have seen some is mentioning LINX and some are mentioning VISA. I am confused between them.

What do you mean by (virtual) COM port of the Arduino?

You have mentioned sensor here, which sensor you mean?

If you have similar project reference from Youtube, so I can understand better, or has the same perspective of connecting Arduino to he LabVIEW interface.

Thanks.

[GerdW]

Hi alsabri,

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@alsabri_71 wrote:

1. I have seen some is mentioning LINX and some are mentioning VISA. I am confused between them.
2. What do you mean by (virtual) COM port of the Arduino?
3. You have mentioned sensor here, which sensor you mean?

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1. LINX provides a runtime engine for your Arduino with several pre-defined capabilities and an interface/API to access those capabilities from a connected host computer running LabVIEW. Using the default VISA communication you can communicate with your Arduino, but then you need/can provide your own Arduino sketch. LINX is limited to what is contained in the provided runtime engine, using VISA+Arduino sketch you can use any Arduino code you want…
2. The Arduino provides a USB connection to a host computer, which by default is handled by a virtual COM port.
3. You already mentioned the HX711 load cell sensor, that is what I'm talking about!