Arduino read analog input serial#

I would really appreciate it if those with more understanding and knowledge could offer their insights and assert my thoughts above and even elaborate on it to further my understanding and clear up some of my misunderstandings. I realise SE prefers Q&A type of posts, but to me the above is context that fits together for the larger circuit - at least that's what I think. Out of my depth, so some insight would be useful. One particular question that I have is about the fact that the ADC and the 24v sensor signal that I'm trying to interface is that they have different power sources, and apparently this is an issue because they don't share the same GND. I'm not certain why this is useful or what it achieves, but I think it seems to help address the mismatch of impedance from the 24v signal and that of the ADC? But I could be wrong.

Voltage buffer / op-amp: I seen references to including this as part of the circuit, but again my ignorance only makes me dangerous at this point.I'm still lost with the whole impedance thing so I'm still unsure about whether to use R1 and R2 sized as say 4.7Kohm and 1.2Kohm or larger by an order of magnitude or two. I should choose my resistor values not only to achieve the desired divided voltage, but also to suit the impedance of the ADC.I can use a simple voltage divider circuit to 'scale down' to 0 - 5v range.

The resolution is good enough for my needs. The ADC is a 10bit for 0-5v so I have roughly 4.88mV per step (total of 1023 steps).I've searched various posts and sites regarding conversion of the 0-24v analog signal to the range 0-5v the ADC on the Arduino Uno (actually Freetronics Eleven with ATmega328P) can interpret. The sensor is has only two connections which is used both for power and signalling.

I have a proprietary 24v DC analog sensor signal that I'm trying to interface with using a Arduino based microcontroller. But the temperature sensor is still in the room temp air! So the pot value, TSet, goes up like it should, but also affects the sensor reading even though the temperature hasn't really changed.Īny advice would be greatly appreciated.Disclaimer: Please be gentle - I'm a newbie with electronics.

Then when I turn the pot up: TempSensor= 40 C, TSet=55 C.

Arduino read analog input serial#

The serial shows TempSensor = 22 C, TSet = 0 C.

The potentiometer is at its 0 position, and the sensor is in the room temperature air.

However, when I adjust the potentiometer it significantly alters the sensor reading. Individually, I have gotten values for both the potentiometer and the temp sensor that make sense (I am monitoring the values on the serial window). The potentiometer sets the desired temp and the sensor reads the current temperature of a little copper plate that is 'the oven.'īoth the temp sensor are connected to their own analog input pin on my arduino uno.