Some load cells might have slight variations in color coding such as blue
instead of green or yellow instead of black or white if there are only four
wires (meaning no wire used as an EMI buffer). You might have to infer a
little from the colors that you have, but in general you will usually see these
colors.
If the readings from the HX711 are opposite of what you are expect
(for example the values decrease as you increase weight) simply
reverse the O+/O- wires.
Once the load cell is is hooked up to the amplifier, you can hook up VDD,
VCC, DAT, CLK, and GND to a microcontroller such as a RedBoard or
Arduino board.
Note
VCC is the analog voltage to power the load cell. VDD is the digital
supply voltage used to set the logic level.
PRO TIP:
In many cases, you can just short VCC and VDD together. If
your microcontroller uses 3.3V logic however, you'll want to connect
VCC to 5V and VDD to 3.3V.
Load cell wires hooked up to the HX711 Amplifier board
The example code has
DAT and CLK
hooked up to
pin 3 and 2
respectively, but this is easily changed in the code. Any GPIO pin will work
for either. Then VCC and VDD just need to be hooked up to 2.7-5V and
GND to ground on your microcontroller.
Fritzing diagram of HX711 amplifier connected to a RedBoard
Now, if you would like to set up four single load sensors with our
combinator board and amplifier, connect the five pins labeled RED, BLK,
WHT, GRN, YLW to the matching pins on the HX711. Next, connect each
of the four load sensors to the following pins:
• Red
→
+
• Black
→
-
• White
→
C
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