I connected HX711 24bit module to MPS20N0040D (wheat stone pressure sensor) and arduino mega2560 and used sample library for HX711. In the serial monitor, I had acceptable number from 1 to around 10kp and more than 10kp just display 0. My sensor should display to 40kp. I changed my sensor and HX711, but this problem repeated.
I need help to solve this problem.
Thank you in advance
No link to the library you're using and no code you use to produce this. Sorry, my crystal ball is in duty today.
The library that is available in the library manager of the IDE provides no kp value but simply the 24bit value the HX711 amplifier supplies.
I used example library in IDE. I connected air compressor and manual gauge to sensor and checked it for calibration. When I increased pressure more than around 10kp (in manual gauge), serial monitor displayed 0! How I can solve this problem?
Library:
#include <Q2HX711.h>
const byte hx711_data_pin = A2;
const byte hx711_clock_pin = A3;
Q2HX711 hx711(hx711_data_pin, hx711_clock_pin);
void setup() {
Serial.begin(9600);
}
void loop() {
Serial.println(hx711.read()/100.0);
delay(500);
}
Have you tried with digital pins 2 and 3?
hello
I have a problem with the weight sensor I can not determine the meaning of the wires I chose a Chinese model how I can determine the wires???
edgemoron:
Have you tried with digital pins 2 and 3?
Yes, I tried, but my problem not solved.
When I increased pressure more than around 10kp (in manual gauge), serial monitor displayed 0! How I can solve this problem?
Start by printing out the raw value you get from hx711.read(). Try again and post the output of your sketch under different loads.
pylon:
Start by printing out the raw value you get from hx711.read(). Try again and post the output of your sketch under different loads.
These are raw value from serial monitor (with arduino UNO and HX710B module) with above mentioned library (more than 70mmHg, all data s are same=167772.15
0 mmHg~ 95168
10 mmHg~ 103177
20mmHg~ 114620
30mmHg~ 126821
40mmHg~ 136783
50mmHg~ 148332
60mmHg~ 160200
70mmHg= 167772.15
80mmHg= 167772.15
90mmHg= 167772.15
...
I tested with different amplifier such as HX710B and HX711, also with different pressure sensors such as MPS20N0040D and SPD005G but in all cases, results are around same (with different raw values)!!!
The HX711 might be clipping (out of range).
Max range of the HX711 is 20, 40, or 80mV, depending on PGA gain setting (code) and channel (a or b).
Sensor offset could already be 25mV, and pressure adds another 50-100mV.
Start by measuring output voltage of the sensor (<25mV), without pressure. Post it.
You might have to use channel B (32x gain.
Would have been a lot easier if you had bought a sensor with buildin instrumentation amp.
Leo..
Wawa:
The HX711 might be clipping (out of range).
Max range of the HX711 is 20, 40, or 80mV, depending on PGA gain setting (code) and channel (a or b).
Sensor offset could already be 25mV, and pressure adds another 50-100mV.
Start by measuring output voltage of the sensor (<25mV), without pressure. Post it.
You might have to use channel B (32x gain.Would have been a lot easier if you had bought a sensor with buildin instrumentation amp.
Leo..
I tested with 2 different Amp (HX710B & HX711) and changed sensor, but both have same result!
I changed to channel B but problem not solve!
Finally, I ordered new pressure sensor with internal Amp (MPXV5050GP). After test, I'll share results.
So what voltage did you measure on A+ and A- without pressure?
And what voltage with max pressure.
You'll never going to learn anything by just moving on to the next thing.
Leo..
Wawa:
So what voltage did you measure on A+ and A- without pressure?
It is 0V.
Wawa:
And what voltage with max pressure.
In 70mmHg~ 15mv
In 300mmHg~ 65mv
imi1937:
It is 0V.
In 70mmHg~ 15mv
In 300mmHg~ 65mv
Exactly 0mV?
15mV is at the edge of the range with a default PGA gain of 128.
I would try dropping the gain of channel A to 64 (in code). Or switching to channel B.
Not sure how to. Maybe someone who has done that could chime in.
Leo..
Wawa:
I would try dropping the gain of channel A to 64 (in code). Or switching to channel B.
It's easy with the bogde library, either in the constructor or a begin statement. https://github.com/bogde/HX711/blob/master/HX711.h
Wawa:
Exactly 0mV?
Around 4mV
DaveEvans:
It's easy with the bogde library, either in the constructor or a begin statement. https://github.com/bogde/HX711/blob/master/HX711.h
I used this library but problem not solve!!!
Did you change the gain to 64
Leo..
Wawa:
Did you change the gain to 64
Leo..
I use below library, but problem exist!
https://github.com/bogde/HX711/blob/master/HX711.h
Post your latest code and the results from that code.
i got same problem, and what solution here?
i tried 32, 64,128
with 32 value alway const not change when pressure change
64,128: max 8388607 raw, and 80mmHg real pressure ~10kPa
help me thanks. How can i measure 40kPa
