4-20mA sensor explained with a simple Arduino example! 

Glad you found it useful Silas!

Mega Amps!

Glad you found it useful!

Hello Paco: glad you found it useful!

Have you took a trail with pressure sensor with ardunio mega. Is it showing correct feedback? Please reply.

Thank you! Glad you found it useful!

Glad you found it useful! Hope you are successful with your project! I'm incorporating these sensors into my 12,500 gallon rainwater collection project right now.

@@werewolfwu In my case, I am designing a Personal Weather Station, the anemometer and the vane both are 4-20mA. Your video helped me a lot to understand the hook-up and calculations, etc. In the meantime, I am using a 4-20mA simulator to get the calculations right before hooking the anemometer and vane, for example, the vane at 8mA (25%) should indicate 90°, at 12 mA (50%) 180°, etc. You are right, in my case, a 160Ω is the magic resistor value for a 3.2V ESP32 Controller. Here is one problem I solved after I watched your video: I was using two power supplies, one for the ESP32 and one for the 4-20mA simulator, that did not work because the grounds MUST be all connected together. I scaled down the 12V to 5V for the ESP32, same ground all over, bingo! Problem solved. Once again, thank you. Happy new year!

That sounds like a great project! Interfacing with the real world and all! Happy new year to you too!

Glad you found it useful!

Glad you found it to be useful!

@@werewolfwuCorrect me if i'm wrong but didn't you miss a black cable in your picture of the drawing going from the 24v to sensor?

@@ChristianGrau92 Hello! Sorry for the late reply. There are only two wires connected to the sensor: red and orange. The best way to internalize the working mode of these sensors is to treat them as "smart" resistors, that adjust itself so that the current flowing through them "happens to" scale perfectly with whatever they are sensing. The common arrangement of "red for power black for ground plus some signals" does not apply to these sensors. Hope this helps!

Glad you found it useful!

:-)

Glad you found it useful!

Which specific aspect of ADC? Perhaps I can help you out in the comment section first. Let me know what you'd like to know about ADCs. We'll see who answers it better: human or AI.

Indeed!

Yes! It's amazing that if you search for LCD screens with i2c for Arduino on the internet, there's pretty much only one kind of model that's available, perhaps with different sizes. And that's what I'm using. I actually don't know what I should call it. I only know that all the sellers sell the same thing and all the libraries that you can find in Arduino are actually just slightly different from each other!

because it is :-)

You would need one power supply and 2 return paths to carry two signals.

Glad it helped!

Hello Diego: if your sensor is a resistive one, it is definitely NOT the same as 4-20mA sensor. You can still use a similar circuit as shown with minimal modification: simply form a resistive divider with your sensor (which is a resistor) and another resistor (say around 100ohms), and sense the divided voltage compared to the reference. This way you get the ratio between the resistors, and hence the resistance value. A little math is needed but not too hard.

should be!

It's a generic module that I bought off Jeff Bezos' establishment. Similar things can be found on all sorts of online retailers, simply search for "5V to 24V converter". Required power level is low, a 50mA output capacity (or higher) is enough.

Not sure if that's a 4-20mA type sensor, that being said you can probably find what you need on Google. Good luck!

😂😂😂 Didn't want to directly name the establishment

Hello Darragh: What you are asking for is essentially the output portion of an actual 4-20mA sensor. There are many ways to create a current source with digital control. e.g. a current DAC or a voltage DAC with a regulating feedback loop etc. If you don't need a lot of resolution, you may want to look at something like Max5550. If you do require a lot of resolution, search for "16 bit current DAC" and there are tons of options out there.

@Werewolf Wu yeah what I am trying see if I can do is use an arduino to drive a 4 to 20 ma positioner.

Thanks and great videos

My humble suggestion would be to use some kind of USB to I2C/SPI converter to control the current DAC on your dev bench. This makes the development easier. Once you have the control of the DAC verified, you can code that into an Arduino of sorts if your application requires it.

@@darraghross4310 glad it helped!

I would politely caution against using 250Ohms for 5V operation: the "5V" on Arduino is often QUITE OFF from 5V. E.g. if the "5V" is actually 4.5V, you'll lose quite a bit of measurement range. In my very humble opinion, it is much better to have a little bit more quantization noise than losing a chunk of measurement range.

I'm working on uploading it! I'll reply back here once I have it uploaded together with the next video.

github.com/WerewolfWu/420mAsensor

Of course! I'll reply back once I put it into the cloud.

github.com/WerewolfWu/420mAsensor

I know right?

indeed!

Yes it is!

It's just a joke man... besides It's trivial to calibrate the zero level and gain etc...

Hello GRM Central Kenya TV: If your reading keeps changing while the water level is not changing, then I would start by swapping out the sensor... :-) These sensors are enclosed micro computer systems, it's quite possible to be broken...

Start with power supply, follow the signal flow, check power supply and signal flow chains at every point.