Author Topic: Force Sensor to Servo  (Read 1147 times)

0 Members and 1 Guest are viewing this topic.

Offline ImignantTopic starter

  • Jr. Member
  • **
  • Posts: 20
  • Helpful? 0
Force Sensor to Servo
« on: April 25, 2010, 02:00:25 PM »
Hello from Iraq, 
I am, or was, building an RC arm with grippers.  I want to use CH 7, which is only an off and on switch, to control the gripper.  My only focus for now is to pick up a full coke can.  I want to connect a FSR to the servo so I can flip the switch and have a controlled grab on the hand.  As is, I have to set the servo at a certain angle which is stressing the servo.
I found a FSR with three leads, is there any way to connect this directly to the servo, as in the potentiometer leads, or do i need some sort of circuitry, or MCU.
Been flying planes for a while but I'm brand new to the microcontroller word.
trying to have it all figured out by the time I go home.
here's the link http://www.trossenrobotics.com/flexiforce-25lb-resistive-force-sensor-4inch.aspx?feed=Froogle
Thanks

Offline Soeren

  • Supreme Robot
  • *****
  • Posts: 4,672
  • Helpful? 227
  • Mind Reading: 0.0
Re: Force Sensor to Servo
« Reply #1 on: April 25, 2010, 05:25:31 PM »
Hi,

My only focus for now is to pick up a full coke can.  I want to connect a FSR to the servo so I can flip the switch and have a controlled grab on the hand.
[...]
I found a FSR with three leads, is there any way to connect this directly to the servo, as in the potentiometer leads, or do i need some sort of circuitry, or MCU.
No, you'd need further circuitry.

The FSR gives out a varying voltage (if used as a potential divider) or a varying resistance, while the servo needs a Pulse Width Modulated signal (Google "Servo signal" to learn more).

It would be much easier for you to use a common DC motor and let the button control a circuit that engage/disengage that and you can get rid of the FSR by just limiting the max. current the motor is allowed to draw (that's how torque control works in most handheld battery drills).
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

 


Get Your Ad Here

data_list