Hi everyone, Fairly new to Arduino (month or two), very new to the forum as an active user (first post). I have been using the code below (picked it up somewhere (unfortunately, cannot recall original source, have seen it come back in several places) along the many forum posts and/or YouTube tutori…

Hi, thank you for your quick reply. I am exploring Arduino as a multiparameter controller, where you can connect multiple (water) sensors (e.g. pH, conductivity, temperature), turn on/off small dosing pumps accordingly, display measurements (OLED display) and store them internally (microSD card), t…

Hi, thank you for your quick reply. Thank you for the code, I will have a look but it seems quite extensive with not that many comments so it will take some time to work my way through it, if I can make sense out of it at all. The way I understand it, that is not how analogReference works. I belie…

Can you give an example of a sensor that outputs an analog voltage that would require to know what the VCC is ? The UNO R4 would be a good board for your project, but there are other boards.

Thank you for your input and making me think. It could be that I am just overcomplicating things with the analog sensors and that I am focusing too much on the absolute value of Vcc, while it is in fact always a ratio of the full range and hence, Vcc cancels itself out in the equations in that case.…

I'm not sure anymore if you use the 5V to measure the 1.1V or use the 1.1V to measure the 5V :dizzy_face: In both cases, you lose accuracy. So you need a good multimeter :dollar: I can't find a schematic of the pH sensor :slightly_frowning_face: Does it output an absolute voltage ? then it is an ex…

Thank you for the Pi/Mbed suggestions. For now, I would like to stick with the things I got myself familiar with (Arduino/IDE), took already enough time and sweat to get to this point :slight_smile: . I understand the 1.1 / 5V 5 / 1.1V is confusing, it got me mixed up at first too. The way I have …

Thanks, the output of the pH module is a voltage directly amplified from the pH probe. That is indeed a voltage. So you need to know the VCC :grimacing: [afbeelding] In these situations, Adafruit sometimes connects the AREF pin to the 3.3V output. Thus using the accuracy of the 3.3V voltage regul…

[image] fdw_arduino: I believe it is used to set/choose the analogReference that is used by the ADC as the full scale reference I thought that too, but analog.cpp has two versions (overloaded, a feature of C++) of analogReference(), so I infer that if you pass it an argument, it sets the refe…

I have read parts of the datasheet (p. 95) , documentation and the code of the analogReference function you provided (thank you) and tried to understand it. I took the original code and added comments myself to try and understand). It seems the internal reference of the RA4M1 is not 1.1V like with t…

Good to have it confirmed that my quest for the correct Vcc is justified. Not sure if the 3.3V is as stable as the 1.1V (I do not remember what I read about it) and how it compares to the stability of 5V - which is probably the worst, being the reason people are looking for accurate ways to measure …

readVcc function using new UNO R4 RA4M1 ADC

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readVcc function using new UNO R4 RA4M1 ADC

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