Hello,
I am using an Arduino Uno/Mega to connect a 100kg S-type load cell(Precision 0.02%FS) to a load cell amplifier.The smallest change in output that I have been able to observe is about 0.100kg.
I wanted to know whether the load cell amplifier gain could be modified to improve the output.If so, would it be possible for you to guide me in that respect?
Thanks.
Links for above mentioned products:
robotshop.com/en/strain-gaug … d-2ch.html
robotshop.com/en/type-s-load … 00-kg.html
Hi,
What voltage are you using for your sensor ?
What voltage are you using for your ADC reverence on the Arduino ?
You can modify the gain but you will need to change the surface mount resistor on the board.
Have you read the blog post about the amplifier ? robotshop.com/blog/en/interf … oard-16247
Best regards,
Hello,
I did post the same question on the blog post and I tried the following recommendations from
Sébastien Parent-Charette
“Yes, the gain can be changed, as mentioned here. Also, please note that RB-Onl-38 works on 3.3 V DC, therefore you should connect the 3.3 V DC to the AREF pin and use this function (external) in your code to ensure maximum accuracy. Also, please note that the Arduino boards do not include a decoupling capacitor on the AREF pin, so we recommend that you add one when you connect it to the 3.3 V DC source.”
I have been able to improve the output a little bit. I have connected the load cell directly to the amplifier shield and a wire from the 3.3V DC port to the AREF port with a 1uF capacitor connected to the 3.3V and the Gnd on the Arduino. On top of the amplifier shield I am using a motor shield and finally a keypad shield. I am currently testing the whole set up using power from a USB port. It seems to be working fine. Still, I am considering to improve the gain. How exactly do I proceed to remove the surface mount resistor and replace it with another one? (desoldering?) . Also, is my current set-up ok?
Thanks.
Links: robotshop.com/en/10a-dc-moto … hield.html
DFRobot Keypad shield for arduino :
dfrobot.com/index.php?route= … tP3v5x97IU
Hi,
Your current setup seems ok.
To change the gain, you must de solder the resistor with the “Gain x” label and solder a new one. See the AD8426 datasheet in the documentation package for the resistor values. Be sure to use 1% resistor to achieve reasonable precision.
Best regards,
