I would like to have a minimum of 0.5-1Khz. I would like to use this sensor for static pressure measurement.
I am using other dynamic pressure sensors with Labview and specialized DAQ that can go up to 500Khz.
But if we can design the circuitry to be able to do 50Khz or 100Khz, that would be also great to have.
I think the HX711 is unsuitable because of the lower supply voltage (<5volt).
The sensor is rated for 10volt, so the INA125 with it's 10volt reference would be a good match.
Supply the INA with 12volt regulated, IAref to ground, and a 1:1 voltage divider on the output.
Leo..
Wawa:
I think the HX711 is unsuitable because of the lower supply voltage (<5volt).
The sensor is rated for 10volt, so the INA125 with it's 10volt reference would be a good match.
Supply the INA with 12volt regulated, IAref to ground, and a 1:1 voltage divider on the output.
Leo..
I find no indication that sensor has active components, probably it's just bridge 4- resistive strain gauges, same as load cell.
My understanding of "rated voltage" is the maximum voltage you may apply accounting dissipated power - accuracy loss due temperature change. Nothing prevents to apply low voltage, down to 1V or less.
Magician:
My understanding of "rated voltage" is the maximum voltage you may apply accounting dissipated power - accuracy loss due temperature change. Nothing prevents to apply low voltage, down to 1V or less.
That's what I also understand. The only thing that also will go down with supply voltage is output voltage.
I think the Sparkfun HX711 is set for 4.3volt bridge supply.
Sensor output will be 43mV max at that voltage.
That has to be weighed against the specs of the amplifier and A/D converters.
Leo..
That's what I also understand. The only thing that also will go down with supply voltage is output voltage.
I think the Sparkfun HX711 is set for 4.3volt bridge supply.
Sensor output will be 43mV max at that voltage.
That has to be weighed against the specs of the amplifier and A/D converters.
I agree, that useful signal level diminishing with lower supply voltage. But for low sampling rate , load cell needs only 1- 10 sps, it's not an issue, as 24-bits adc brings 16384x additional gain compare to arduino's 10-bits ADC. The problem may arise if required sampling rate > 1 msps, where high resolution ADC isn't accessible or cost too much.
Author wants 1 ksps, so Hx711 is not an option, but I'd look at ADS1115
IMHO, external ADC with internal PGA is better option, than design INA125 board + 10V power supply interface like they did in 80-x or 90-x, luckily price for such module is quite reasonable.
In my opinion, board is obsolete. You will have to design another interface stage between board(+-12V) and arduino(+5V).
Doesn't make sense. I change my mind saying INA125 in the beginning (so INA122 - single supply 'd be better), to AD7705 or ADS1115 module, but external ADC brings better resolution, sooner or later you 'll realize that arduino's 10-bits is not enough
Getting better resolution, and programmable gain is great. I actually found also a step by step tutorial on Adafruit on how to wire the ADS1115. This would work great as a start.
The only limitation is that the maximum data sampling rate is 860 samples/s.
What are my alternatives if I want to have a high speed data rate (lets say 50Khz) ?
My pressure sensor natural frequency is 700Khz, if I understand correctly this means that I can sample data (and still be safe) at about 20%, or 140 Khz.
I am not sure how complicated this would get, but would like to hear your thoughts about it.
That can't be right. To say that you need to sample your pressure sensor at it's natural frequency doesn't make sense. It should not make any difference how often you sample it. If it is a pressure sensor , it outputs the pressure, period. Suggesting you need to sample it at 140khz sounds absurd. I didn't see anything on the datasheet that supports your suggestion. I would call the company and ask to speak to an Applications Engineer and ask him what sample frequency he recommends.
Let's keep in mind you said this:
I am a beginner in arduino, and electronics in general.
Hi,
Are you going still use the kulite pressure sensor?
Are you aware that it is just a pressure load cell, you need exictation voltage in E+ and E- and you read a differential output from S+ and S-.
So you will need a differential AtoD to read it.
To get 100mV you are going to need 10V excitation.
There are AtoD that are designed for load cells applications HX711.
What is the application that requires such high sample rates?