Multiple hall-sensors uneven analog readings

Other Hardware Sensors
1

Hi every one

I'm desperately trying to get multiple hall sensors (SS49E) to work at the same time on an arduino nano.
When only one hall sensor ist connected everything ist working fine. But when I hook up five of them, the analog reading are very uneven.
Here's the setup:

812×756 106 KB

Here is my code:

byte inputPin[] = {A0, A1, A2, A3, A4}; // Pins on which the hall-sensors are connected

void setup() {
  Serial.begin(9600);
  for (int i = 0; i < 5; i++) {
    pinMode(inputPin[i], INPUT); //initialize all pins as input
  }
}

void loop() {
  for (int i = 0; i < 5; i++) {
    Serial.print(analogRead(inputPin[i]));
    Serial.print("t         ");
  }
  Serial.println("");
}

This is the output:

163	         859	         265	         820	         357	         
803	         446	         699	         530	         550	         
655	         445	         786	         346	         894	         
259	         928	         202	         951	         130	         
982	         155	         955	         193	         951	         
242	         894	         300	         839	         347	         
764	         412	         670	         521	         542	         
645	         436	         777	         333	         883	         
251	         923	         199	         948	         127	         
976	         149	         954	         188	         943	         
234	         886	         292	         833	         337	         
762	         407	         670	         515	         536	         
639	         431	         769	         326	         875

Here's what i've tried so far:

  • add a delay after each reading
  • add a second analogread() in front of the one that is printed
  • adding a smoothing-function for the read outs

I'm clueless...

Does anyone have a clue why I don't get stable readings?
Do the sensors have to be more spread out?

I am happy about every input. Thanks in advance and have a great day!

2

blacklotus1990:
I'm clueless...

So are we :frowning:

Honeywell SS49E: SS39ET, SS49E, SS59ET Linear Sensor ICs | Honeywell.

Can you measure the voltage of the 5V pin ? It should be about 4.5V for an Arduino Nano. Get a better USB cable if it is below 4.0V.
The one that works, gave it a value of about 512 ?
Can you test the others one by one ?
If one sensor works, but not five together, will two sensors work ? and three ?
Do you use a breadboard and jumper wires ? There are many problems with broken jumper wires and breadboards with bad contacts.

Can you show of a photo of it ?

3

Check the wiring (with a meter). Are these a long way from the Arduino? If so you'll probably
need supply decoupling close to the sensor chip.

Did you buy from a reputable supplier? Expensive sensors like this are very likely to be fakes
if bought from a random seller on eBay etc, these days only reputable electronic suppliers can be
trusted for any semiconductor.

4

Double check your sensors' connection

5

Thank you guys.
It turns out my Arduino was broken and it was not able to provide the needed voltage...

It's working perfectly now!

Have a great day!