levitation system - pid controller

[ymmen]

Iam trying to design a magnetic Levitation System, with the help of solenoid, a magnet and PID controller. As iam using a hallsensor for sensing position of magnet and interfacing it with arduino, i dont get much range of voltage i.e. in arduino value varies from 350 to 500 with magnet and without magnet. how to increase the range?

 

[mobinmk]

which hall senser ic ,u used ??
vcc voltage ??

if u wana to use nly sense the position of magnet,

On (LOW) with magnetic South Pole and Off (HIGH) without magnetic field or
with magnetic North Pole, if you need inverted output, use a NPN Transistor like
BC547 or FET or inverter chip like CMOS CD40106 or TTL 74LS04

or use an opamp and get 2 level

then connect to the pin 2 of arduino

 

[ymmen]

i gave 5V as VCC. As under no magnetic field the sensor gives 2.5 V, with a gain=2, it will give 5V which will be above the range of voltage that arduino can sense. what VCC should i provide then?

 

[mobinmk]

which hall sensor ic is used??

check datashet

 

[ymmen]

which hall sensor ic is used??

check datashet

one more question has arised i was experimenting, how does frequency of PWM generated for solenoid effectthe whole system, and how should i decide the optimum frequency to be used?