S2 Ping))) Object and a FREE Offer

Phil Pilgrim (PhiPi) · 2012-08-20 12:39

Here's a brand new approach that uses PASM (and no pre-calibration):

CON

  _clkmode      = xtal1 + pll16x
  _xinfreq      = 5_000_000

  PING_PIN      = 0

OBJ

  pst   :       "parallax serial terminal"

VAR

  long echo

PUB  start

  pst.start(38400)
  cognew(@ping, @echo)
  repeat
    pst.char(1)
    pst.dec(dist_mm)
    pst.char(11)

PUB dist_mm

  return (((echo / 80) >> 1) * 10_000 / 29034 - 87) #> 0

DAT

ping          mov       dira,pin_mask
              test      cnt_mask,cnt wc
        if_c  jmp       #ping
        
:wait_hi      test      cnt_mask,cnt wc
        if_nc jmp       #:wait_hi

              mov       outa,pin_mask
              mov       dira,pin_mask
:wait_pulse   test      pulse_mask,cnt wc
        if_nc jmp       #:wait_pulse

              mov       outa,#0

:wait_wait    test      wait_mask,cnt wc
        if_nc jmp       #:wait_wait
        
              mov       dira,#0 
              neg       time,cnt

:echo_loop    mov       dira,pin_mask
              mov       dira,#0
              nop
              nop
              nop
              test      pin_mask,ina wc
        if_c  jmp       #:echo_loop

              add       time,cnt
              wrlong    time,par              
              jmp       #ping

cnt_mask      long      $0040_0000
pulse_mask    long      $0002_0000
wait_mask     long      $0001_0000
pin_mask      long      1 << PING_PIN

time          res       1

-Phil

Ttailspin · 2012-08-20 20:01

This is working great! Phil, no problems to report..:blank:
I will let it heat up for a while, and see whats to see. it's only been running ten minutes or so...

The problem is that the pulse that has to be detected is so short and so runty, that nothing short of waitpeq in Spin will catch it. And, if waitpeq misses it, well, you know what happens then.

Can't tell you how much this short explanation cleared some things up for me. Thanks very much.:thumb:

-Tommy

Phil Pilgrim (PhiPi) · 2012-08-21 09:39

I'm much happier with the new code, since the Ping))) pin isn't being driven all the time during the detect interval, but just pulsed low then tri-stated again. I've created an object from the new code and replaced the previous version in the first post with it.

-Phil

Ttailspin · 2012-08-22 17:29

Works great Phil, thank you for your time with this. :thumb::thumb:

Here is my version of "Roaming with a Ping((("

CON
  _CLKMODE = XTAL1 + PLL16X
  _CLKFREQ = 5_000_000
  PING_PIN      = 0
  
OBJ
  S2       : "S2"
  S2_ping  : "S2_ping"
  
PUB Main | distance
  S2.start                                ' Start S2 object
  
  S2.set_led(s2#POWER, s2#BLUE)           ' Turn on the power LED.
  
  S2.start_motors                         ' Start motor controller
  S2_ping.start(PING_PIN)                 ' Start Ping((( controller
  repeat
    S2.move_now(100, 100, 0, 10, 1)       ' Forward until preempted.
    
    distance := (S2_ping.dist_mm)         ' Get distance reading from ping(((
    
    if distance < 170                     ' if distance less then 170 then...
    
      S2.stop_now                         ' Stop moving
           
      S2.set_speed(15)                    ' Set turning speed 
        S2.begin_path                       ' Begin path
        S2.turn_deg(-90)                    ' Turn right.
        S2.end_path                         ' End movements
        S2.wait_stop                        ' Wait for turn to complete

Not the fanciest code, but she works...

-Tommy

mindrobots · 2012-08-22 17:39

Oooh, oooh!! I forgot to share yesterday.

I loaded the new code, put my PING))) in my new holder and went measuring distances. It worked like a champ for about 30 minutes of playing.

Well done!!!

Now, I'll have to go roaming with Tommy's code. My S2 hasn't had this much attention in a long time!!

Hmmm.....wonder how the S2 would like running under Forth? Hmmm......

erco · 2012-08-22 19:29

Sounds like Phil split the atom AGAIN! Great work PhiPi, as usual, there nothing you can't make the S2 do. How's your hovering object coming along?

Phil Pilgrim (PhiPi) · 2012-08-22 19:57

erco wrote:

How's your hovering object coming along?

There's no hope in that department, I'm afraid, since there's no way I could test such a thing. Lack of eye-hand coordination renders me useless as an RC pilot.

-Phil

erco · 2012-08-23 10:16

Hmm. Parallax ought to pull a Skycrane maneuver, lowering an S2 to the ground from a hovering ELEV-8.

mindrobots · 2012-08-23 10:56

Can we have "Ride of the Valkyries" playing the background??

I love the smell of magic smoke in the morning...
... it smells like.....testing!

S2 Ping))) Object and a FREE Offer

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