Okay, if feel like the question may have too much baggage. I just want to clarify what I want to do, simply.
OBJECTIVE: I want to calibrate, then record output variations from (1) a Hall Effect Sensor and (2) an FET and record them both onto a txt file.
Lets start with (1): Has anyone had experience with this specific melexis hall effect sensor US5881? I read the following thread:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1244878863/0
It helped a bit to understand, but it never reached a conclusion. Right now I have pin 1 of the sensor to 5V, pin 2 to gnd, and pin 3 to analog 0. Here's my code and pictures.
int inPin = 0; // select the input pin for the Hall Effect Sensor
int val = 0; // variable to store the value coming from the sensor
void setup() {
Serial.begin(300); // connect to the serial port
}
void loop() {
val = analogRead(inPin); // read the Hall Effect Sensor
Serial.println(val);
}
RESULT: Outputs 0-10 depending on whether I have my hand or ceramic magnetic in the vicinity.
ALT 1: putting 10k pullup from output to 5v brings the serial out to a constant 0.
ALT 2: i put a 100nF ceramic cap between out and ground. it varies around 3-4 and when i take it out suddenly, the value goes high and starts decreasing back to 0-10.
ALT 3: i put the capacitor between 5v and gnd ... it goes high and then saturates low.
NOTE: i put my hand near the device (a ceramic magnet is useless) and then pull it away, the value goes up to around 30! if i wave my hand, the output varies. maybe the sensor is dependent on the frequency of the magnetic field?
Any ideas?