Conversion

Comments

• Mike Green Posts: 23,101

  2013-01-30 21:18 edited 2013-01-30 21:18

  You need to provide more information about what you're doing. At the very least, provide your source code and a description of how you have things connected.
  
  
  
  If you're referring to the use of RCTIME to measure the resistance of the sensor where RCTIME provides a time value, you'll have to calibrate your system using test weights. The BASIC Stamp Syntax and Reference Manual discusses the use of RCTIME to measure resistance and shows how the resistance can be calculated from the capacitance used and the time measured. Look at this article from the manufacturer's FAQs. In addition to using curve fitting to get an equation for force vs. resistance, you can use the Stamp's LOOKDOWN statement.
• NWCCTV Posts: 3,629

  2013-01-30 21:22 edited 2013-01-30 21:22

  You mean something like this? I used this and once the pressure on the sensor hit the 50000 it would move my bot forward.
  

  IF rawforce >=50000 THEN
  FREQOUT 4, 1500, 1000
  FREQOUT 4, 1500, 1500
  FREQOUT 4, 1500, 2000
  FOR counter = 1 TO 300
  PULSOUT 13, 2030
  PULSOUT 12, 1627
  PULSOUT 14,1650
  PAUSE 20
  DEBUG CLS
  NEXT
  ENDIF
  
• Lizzy1118 Posts: 3

  2013-01-30 22:07 edited 2013-01-30 22:07

  This is my program,
  
  Code:
  
  ' {$STAMP BS2}
  ' {$PBASIC 2.5}
  
  time VAR Word
  sensorPin CON 15
  DO
  HIGH sensorPin
  PAUSE 100
  RCTIME sensorPin,1,time
  DEBUG HOME, "time = ", DEC5 time, CR
  
  IF time>10 THEN
  HIGH 14
  PAUSE 500
  
  ELSE
  LOW 14
  PAUSE 500
  ENDIF
  
  LOOP
  
  The program objective is detect the force applied on a flexiforce sensor, if the force applied is greater than the number assigned then power on a LED, I need to convert the RCTIME into force.
• Tracy Allen Posts: 6,667

  2013-01-30 22:43 edited 2013-01-30 22:43

  This same question came up here on this forum about a week ago, too, how to convert the RCTIME value to force, from the flexiforce sensor. Basically, force is inversely proportional to resistance.
• NWCCTV Posts: 3,629

  2013-01-30 22:52 edited 2013-01-30 22:52

  Still using RCTIME change time to rawforce. Worked for me.
  

  ' {$PBASIC 2.5}
  ' {$PORT COM1}
  ' -----[ Declarations ]----------------------------------------------------
  counter VAR Word
  rawForce VAR Word ' Stores raw output
  sensorPin PIN 14 ' Flexiforce sensor circuit
  duration VAR Word
  ' -----[ Main Routine ]----------------------------------------------------
  Measure:
  HIGH sensorPin ' Discharge the capacitor
  PAUSE 2
  RCTIME sensorPin,1,rawForce ' Measure RC charge time
  DEBUG HOME, "Flexiforce raw output = ", DEC rawForce,CR
  
  IF rawforce >=50000 THEN
  FREQOUT 4, 1500, 1000
  FREQOUT 4, 1500, 1500
  FREQOUT 4, 1500, 2000
  FOR counter = 1 TO 300
  PULSOUT 13, 2030
  PULSOUT 12, 1627
  PULSOUT 14,1650
  PAUSE 20
  DEBUG CLS
  NEXT
  ENDIF
  GOTO Measure
  
• Lizzy1118 Posts: 3

  2013-01-30 23:26 edited 2013-01-30 23:26

  Thanks, I appreciate everyone's help.