# Torque meter sensor

Hello,

I have an HBM T22 torque meter sensor and I need to read this with arduino.

It's possible to read this directly from arduino due analog pins (12bits) ? It's necessary ADC ?

I don't understand how is possible to read this sensor .. It's similar to load cell ?

Yes, if you want to measure an analog voltage with an Arduino.

t's possible to read this directly from arduino due

No, the voltage output from the sensor is ± 5V so the output voltage must be offset and scaled to be compatible with the Arduino ADC. Here is an article on scaling and offsetting a bipolar signal for input to an ADC.

I would put a resistor on pin L to turn the current output back into a voltage for the Arduino. This does not go negative so no bias is required.

You want 18mA to go to 5V so a 277 ohm resistor would be perfect. But that isn't a standard value. 220 ohms is the closest you will see in the 5% tolerances. Or maybe a 250 ohm precision resistor would be good.

MorganS:
You want 18mA to go to 5V…

…but the Due reference is 3.3v so use a 180 ohm resistor.

Using an external voltage reference (<= 3.3v) that is more stable than the on-board regulator is apparently possible with some work.

Hi,

Thanks for the help.

I don't understand how to connect the pinout of this.. If I use the ADS1115 ADC to convert and aplify the singnal, sensor connect directly from PIN C and D to A1 and A2 ?

Resolution: 16 Bits
Programmable Sample Rate: 8 to 860 Samples/Second
Power Supply/Logic Levels: 2.0V to 5.5V
Low Current Consumption: Continuous Mode: Only 150µA Single-Shot Mode: Auto Shut-Down
Internal Low-Drift Voltage Reference
Internal Oscillator
Internal PGA: up to x16
Four Single-Ended or 2 Differential Inputs
Programmable Comparator

The torq is obtained by the diference between C and D pin in volts and converted with math formula to torque ??

Anyone knows an industrial solution to this problem?

C is a 5 volt DC voltage out.
D is ground.

create a voltage divider (couple of resistors) to get the 5v to 3.3 v

pick any of the Ax pins. A0 if you like.

tie A0 to the center of the resistor voltage divider
tie the lower value resistor to C
tie the higher value to D AND to your ground on your arduino. (important)

take 3 of the 10k resistors.
tie them end to end thusly,

C ----///---A0-----///-------///-----D

# connect one end to C, the other to D as shown. tie A0 to the connection between the first two.

for the math, I did not follow the link you posted to that particular make and model device to see what 0 means and what 5V means. nor to see if it is a linear output.

the above will get you readings right away.
a higher resolution ADC will be connected in the same way, but offer more bits of resolution
the on-board will divide the input by 1024 steps.
the ADS1115 will offer 65,536 steps.

any math in your sketch will apply with only a slight alteration of the total bit resolution of the ADC for scaling purposes.
with the exception that with the 16 bit, you might overflow your FLOAT register if you try to multiply.....

===================

first off, get a PLC and not an arduino. the Arduino does not qualify as industrial.
second, buy the device that this connects to.

industrial solution is simple, all you need is a link to the suppliers and a check book.

to review
post #5 shows the simple, albeit crude way to connect and get readings (now)

post #3 adds that if you want higher accuracy, an accurate and stable, voltage reference will be advised.

post #2 offers a way to use the mA (current, not voltage) output. this brings it's own challenges, and benefits.

post #4 shows a higher resolution ADC is available, but brings a bit more work

I would offer that the simple voltage dividers, connect to your on-board ADC and ground the two devices and you will have readings of some sort today.

there is a saying that you can get 90% accurate with 90% of the work.
it will take 900% more work to get the next 90%
and 900% to get the next 90%.....

with the resistors, you can connect them, then test with your multi-meter today.
( you might be able to use 1k ohm resistors in lieu of the 10k )
get your Arduino to output a value in 20 minutes or so. allowing time to heat the soldering iron and self questioning and triple checking..... then connecting device grounds D on the device, gnd on the arduino

first sketch to see results with the resistors. right out of the free examples in the Arduino IDE software.
0 to 100%

revisions to scale your results in software, another 20 minutes to 'figure it out'
0 to xx inch pounds or whatever you want.

== then....

get the ADS11115 and also get an external precision voltage reference source (wait a week for parts)
put them behind the resistors
couple of hours for a ham-fisted, un-sure noob... (sorry, no insult intended)

get higher resolution and a bit more stable and repeatable results.

joy will be had at each step of the way !

based on this ?