Elapsed Timer Demo ..Need help.. Clock dose not always restart after removing p

Comments

• Beau Schwabe Posts: 6,572

  2008-07-15 16:01 edited 2008-07-15 16:01

  sam_sam_sam,
  ·
  By adding any additional circuitry to X1 and X2·assigned to the crystal, you negate any kind of accuracy the crystal was able to provide.· The connection to the crystal is very particular and any added capacitance can slow down or kill the oscillator.
  ·
  That said, I don't think that is what you are experiencing...· by placing power on the X1 pin you force the internal oscillator inverter to stay in one state, thus stopping the clock.· When you remove that condition, the oscillator will sometimes start,·most likely because of a noisy condition on your reset switch.· If the noise on the switch is relatively clean however, the oscillator won't start, because the crystal has lost it energy momentum and it can't override the 10k pull-down that's still on the input (X1)·of the oscillator.
  ·
  If·you must "gate" the crystal input like this, I would get rid of the resistor divider scheme, and use an open-collector transistor configuration that pulls X1 to ground and keep the leads as short as·possible from the transistor collector to X1.
  ·
  
  ·
  
  Edit:
  
  sam_sam_sam,
  
  I think I completely misread your post... I thought you were putting power to pin #2 on the RTC.
  
  I can't offer any advice, other than are you sure you are connected to the 3rd input on the BS2 and not the 2nd ... IN0, IN1, IN2
  
  
  
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  Beau Schwabe
  
  IC Layout Engineer
  Parallax, Inc.
  
  Post Edited (Beau Schwabe (Parallax)) : 7/15/2008 4:15:58 PM GMT
• sam_sam_sam Posts: 2,286

  2008-07-15 16:32 edited 2008-07-15 16:32

  Beau Schwabe·
  
  ·
  I I can't offer any advice, other than are you sure you are connected to the 3rd input on the BS2 and not the 2nd ... IN0, IN1, IN2
  
  I should have made it more clear than·I did·
  
  I am using·IN2 on the Basic Stamp
  
  
  
  I have a 10k ohm rest from··I\O pin 2 to vss and from· ·I\O·2 pin·a 220· ohm rest to vdd when powering·I\O pin on # 2 on the Basic Stamp
  
  ·Now if i do not use this part in the routine them the clock will start every time·with·no problem except the second start over·
  
  Now I could use that way and just have a counter that counts how many starts there are but this would be my second choice
  
  ·
  
  ·reg = $80······································· ' Point to register 80h
  ioByte = secs + 128·························· ' Set Clock Halt Bit
  GOSUB RTC_Out······························· ' Send Command
  
  Is there a way to fix this part of the routine or add some thing to it ··
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  ··Thanks for any··that you may have and all of your time finding them
  
  ·
  ·
  ·
  ·
  Sam
• Beau Schwabe Posts: 6,572

  2008-07-15 16:41 edited 2008-07-15 16:41

  sam_sam_sam,
  
  Ahhh! Try OR'ing the 'secs' with 128... if the seconds already have 128 added (i.e. the bit set), then you don't want to do it again...
  

   reg = $80                                   ' Point to register 80h
  ioByte = secs | 128                          ' Set Clock Halt Bit
  GOSUB RTC_Out                                ' Send Command
  
  

  
  Likewise for similar reasons, where you have this...
  

  ioByte = ioByte - 128                              ' Clear Clock Halt Bit
  

  
  ...use this instead...
  

  ioByte = ioByte & 127                              ' Clear Clock Halt Bit
  

  
  ·
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  Beau Schwabe
  
  IC Layout Engineer
  Parallax, Inc.
  
  Post Edited (Beau Schwabe (Parallax)) : 7/15/2008 4:52:49 PM GMT
• kelvin james Posts: 531

  2008-07-15 17:02 edited 2008-07-15 17:02

  I am wary of the " gosub main " line. There is no return from the gosub. I think a " goto main " should be used.
• sam_sam_sam Posts: 2,286

  2008-07-15 20:48 edited 2008-07-15 20:48

  I fix it with a way that I can live with when the timer restarts it go to 30 seconds every time
  By adding this· secs = 30
  
  
  reg = $80·················· ·' Point to register 80h
  ioByte = %0110000····· ·' starts the clock by clearing the Clock Halt bit
  ·································' and·sets the·Seconds to "30"
  GOSUB RTC_Out·········· ·' Send Command
  
  ·······························instead of· %0000000 which·resets· seconds· to = 00
  
  DO
  · GOSUB Get_Time
  ·· DEBUG HOME, HEX2 day, " DAY···· ",· HEX2 hrs, " HRs····· ",
  ························· HEX2 mins, " MINs····· ", HEX2 secs, " secs "
  
  · INPUT 2····································· ·' Make P2 an input
  · DEBUG· CR, CR, "State of P2: ",
  ······· BIN1 IN2, CR
  
  ·LOOP UNTIL IN2 = 1
  
  ·DO
  ·reg = $80··································· ·' Point to register 80h
  ioByte = %10000000····················· ·' Set Clock Halt Bit
  GOSUB RTC_Out·························· · ' Send Command
  LOOP UNTIL IN2 = 0
  
  reg = $80··································· ·' Point to register 80h
  ioByte = %0110000······················ ·'·starts the clock by clearing·
  ················································· '·the·Clock·Halt bit and clears
  ··················································'·the·Second to"00"
  GOSUB RTC_Out························· ·' Send Command
  
  GOTO· main
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  ··Thanks for any··that you may have and all of your time finding them
  
  ·
  ·
  ·
  ·
  Sam
  
  Post Edited (sam_sam_sam) : 7/16/2008 11:29:36 AM GMT