Scribbler and PAK IV connected

Bergamotoff · 2008-01-30 13:14

Hello

Just to share bit of gained knowledge! "Hacker port" on Scribbler motherboard is connected to 3 LED's. That means that there is 1.5 voltage drop on those pins.·If PAK IV I/O coprocessor (or any other) is connected to "hacker port" it will not sense·SHIFTOUT·data from BS2. And will not produce any action.
After disconnecting all LED's from "hacker" port (installed small DIP switches to be able enable them if I will ever need them) PAK IV·is performing remarkable well. I solved that mistery thank's to PARALLAX USB osciloscope [noparse]:)[/noparse]

Bet regards

Janis

Whit · 2008-01-30 14:10

Bergamotoff,

Thanks for the info. Did I miss some prevous post about you trying to add the PAK IV coprocessor? I'd love more details.

You've got the most hacked Scribbler around!

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Whit+

"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Bergamotoff · 2008-01-30 15:31

Hello Whit
Actually I missed to tell about my plans. See picture for some clarification. But in brief -
"Hacker port" 3 available pins are connected to PAK IV I/O coprosessor (done, tested, working).

clock· P08
data·· P09
bussy· P10

I/O coprocessor is to control (relay SHIFTIN/SHIFTOUT commands from BS2)

PAK-II Math Coprocessor
PAK-XI Mouse Coprocessor for autonomously tracking my wheel encoder outputs and reporting to BS2 on request
L293D quadruple half-H driver for motors, as I'm not happy with original controller performance (see side note*)
small red laser diode to indicate intended waypoint or object

At this stage coprocessor board will be made as plug in card (check previous posts how EB500 is plugged in to my Scribbler. Coprocessor card will be plugged exactly the same way on other side.· Eventually Scribbler will have 2 connectors for boards on the top)
My next (after this) weekend is supposed to be free and I hope to be able to post report about MHS ("Most hacked scribbler", tank's for idea Whit) update in "completed projects section.
Janis
* problem with Scribbler motor controller
There is unpredictable left wheel speed difference against right one every time I turn on Scribbler. One wheel only. It's always slower than other. But amount of "ticks" it is delayed is always different. I don't know what's SCENIX microcontrolelr is doing there and have no other option as replace this controller with my own I know how to test. Unless some magical gury fairy will help me get it right [noparse]:)[/noparse]

'  {$STAMP BS2}
'  {$PBASIC 2.5}
'  most code by [url=http://www.awce.com/]http://www.awce.com[/url]
'  PAK IV coprocessor board for scribbler test
 
datap   CON 9   ' Data pin (I/O)
clk     CON 10     ' Clk pin (output)
datapin VAR IN8

OUTPUT clk
OUTPUT datap
cmd       VAR Byte  ' command to PAK
response  VAR Byte  ' return value from PAK

DEBUG CLS
GOSUB Xreset        ' always reset 1st!
cmd= %10110110      ' test chip online
GOSUB pakcmd
IF response = $42 THEN
    DEBUG "PACK IV is on-line" ,CR
ELSE
    DEBUG "PACK IV not detected" ,CR
ENDIF
DO
  cmd= %01000001    ' toggle it indefinatelly
  GOSUB pakcmd
  PAUSE 500
LOOP
END
'========================================================
pakcmd:
  SHIFTOUT datap,clk,MSBFIRST,[noparse][[/noparse]cmd]        ' send command
  INPUT DATAP                              ' preparing pin for response
  wait4pak:
  IF DATAPIN=1 THEN wait4pak               ' PAK is bussy
  SHIFTIN datap,clk,MSBPRE,[noparse][[/noparse]response]      ' read response
RETURN
XReset:
  LOW DATAP
  LOW CLK
  HIGH CLK
  HIGH DATAP
  LOW CLK
RETURN

Post Edited (Bergamotoff) : 1/30/2008 8:03:35 PM GMT

Chris Savage · 2008-01-30 20:16

Both the USB Scope and the BASIC Stamp Logic Analyzer (BSLA) are invaluable tools for diagnosing problems in circuits, especially when communication failures are involved. Just today I was demonstrating to another how to troubleshoot communication issues with a GPS Module.

Another seemingly hidden gem is the BSLA and its ability to decode signals. Many people aren’t aware that the BSLA can decode I2C, SPI and Asynchronous Serial data. This can often lead to the causes of communication issues with I/O chips or other peripheral devices. I find that I use both devices an average of once a day. Even before I came to Parallax I used my scope almost every day.

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Chris Savage
Parallax Tech Support

Bergamotoff · 2008-01-30 20:36

Somebody maybe dream about Ferrari. For me my Honda is perfect. But I do dream about professional, desktop digital oscyloscope, signal generator, counter, microscope to work with SMD's ... [noparse]:)[/noparse] And I will have ALL of them ... once I'll really need them [noparse]:)[/noparse] For now USB Scope is doing exactly·what I need. Thank's Chris about reminding of USB BSLA ... that's my next purchase!

Janis

Scribbler and PAK IV connected

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