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Is there a way to grab values from a basic stamp with python?

I just bought a Accelerometer and want to read the values with python.

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Good follow-up from — sending the Stamp’s debug output to a host process is a simple, effective approach and answers ’s request for specifics. The posted method works for quick experiments but benefits from a few robustness and usability improvements so the stream is reliable, easy to parse, and produces smooth cursor motion or clean CSV logs for Excel.

Key points and pitfalls:

  • Serial parameters must match on both ends (baud, parity, stop bits, timeout) and the correct COM device and drivers should be confirmed before parsing.
  • Emit a simple, stable delimitered format from the Stamp (CSV or labelled fields) so the host code does not rely on token positions.
  • Replace a blanket except: with targeted exception handling (ValueError/IndexError/SerialException) and use a serial timeout to avoid indefinite blocking.
  • Calibrate raw sensor min/max first, then map and clamp to screen coordinates. Add a deadzone and a low-pass (EMA) filter to remove jitter from the accelerometer-derived cursor.
  • Many BASIC Stamp models lack a native ADC; PULSIN/RC timing works but is noisy and lower resolution—use an external ADC or a microcontroller with ADC (e.g., Arduino) if precision is needed.
  • For GUI integration, run serial reads in a dedicated thread or async loop so the UI remains responsive.

Recommended small examples (formatting + robust parse):

PBASIC-style output (single CSV line):

' Example PBASIC debug format
DEBUG DEC x, ",", DEC y, CR

Python parsing sketch (robust, with smoothing and CSV logging):

with serial.Serial(port, baudrate, timeout=0.5) as s:
    line = s.readline().decode().strip()
    parts = line.split(',')
    try:
        ax, ay = int(parts[0]), int(parts[1])
    except (ValueError, IndexError):
        continue
    # apply calibration, deadzone, EMA smoothing, then map to screen coords

These additions make the solution repeatable, easier to calibrate, and safer to run long-term—use the CSV log for Excel analysis and iterate on calibration and filter parameters for the smoothest cursor mapping.

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Member Avatar for programmersbook

Hi!

Can you be more specific?

Member Avatar for Tech B

I have values in the Basic Stamps debugger and only in the debugger. I want python to be able to read the values. I'm going to map the mouse movements on the computer with the values, and possibly port the values into excel to be graphed. I can do all of that with python except read the values from the stamp.

Member Avatar for Tech B

After putting down this project and revisiting it after several months, I solved it. No click events yet, but it wont be hard at all.
here is the BASIC code that is loaded into the microcontrollers memory:

' {$STAMP BS2}
' {$PBASIC 2.5}

x VAR Word
y VAR Word

DO

  PULSIN 8, 1, x
  PULSIN 7, 1, y
  DEBUG LF, ? x , ? y

LOOP

And this is the python code to map the accelorometer to the mouse movements.
Requires PySerial.

from ctypes import *
import serial
s = serial.Serial('COM5') # this will be different for everyone, I used a Serial to USB cable.
user = windll.user32
x = 0
y = 0
speed = 10
while 1:
  try:
    d = s.readline()
    d = d.split()
    if int(d[2]) > 2700:
        print 'right'
        if x < 1400:
            x += speed
    elif int(d[2]) < 2400:
        print 'left'
        if x > 0:
            x -= speed
    if int(d[5]) > 2600:
        print 'up'
        if y > 0:
            y -= speed
    elif int(d[5]) < 2400:
        print 'down'
        if y < 900:
            y += speed
    user.SetCursorPos(x,y)
  except: pass
Edited by Tech B because: n/a
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