wiki:DevelopGuide

Version 28 (modified by Frédéric, 16 years ago) ( diff )

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Papywizard Developper Guide

Introduction

Papywizard is entirely written in python. It uses PyGTK (Python bindings for GTK) toolkit for the GUI, and a few additional modules, mainly for hardware control (pybluez and pyserial). Optionnaly, vpython (OpenGL-based module) can also be used to simulate the position of the head (note that this will be soon a separate application).

API

The API documentation is available as web page in the html/ directory.

Architecture

Papywizard uses a MVC-like pattern, which keeps the model separated from the views. This allows to use any other toolkit if needed; I recently switched from Tkinter to PyGTK, to run Papywizard on Nokia plateform. I hope, one day, to be able to run Papywizard on QTopia-based devices, like Openmoko. But I first need to get such device ;o)

Low-levels routines which control the hardware are also in their own package; I plan to made them even more modular, to be used in an external project to control the head. For know, only Merlin/Orion head is supported, but it is very easy to implement other heads.

A word about the simulation (to come).

Hardware

Merlin/Orion protocole

The head uses a simple ascii serial protocol; the serial line uses standard settings: 9600 8N1 (9600 bauds, 8 bits data, no parity, 1 stop bit). The head waits for incoming commands, and send response to them. The 2 axis are identical, and uses the same commands. They both wait for incoming commands; depending of the first value (see below), the command will be sent to one or the other axis.

A commands always starts with ':', and ends with '\r'. The head response always starts with '=', and also ends with '\r'. As TX/RX lines are wired together, the controller has to first readback its own command, before reading the head response. In the following documentation, the command readback is omitted, as the ':', '=' and '\r' chars.

Parameters used in the documentation:

  • <axe>: 1=vertical, 2=horizontal (1 ascii digit)
  • <pos> position coded with 24 bits (6 ascii digits, hex). .
ParameterWhatallowed valueFormatNote
<axis>axis to control1 or 21 ascii digit1=yaw, 2=pitch axis
<pos>position0 to 2²⁴-16 ascii digits, hex.low byte is sent first (A35483 is read 8354A3). When switched on, read value is 800000. Right sens increments axis 1; left sens decrements it. Up sens increments axis 2; down decrements it. A complete turn (360°) increments/decrements by 0E6600 (so, the axis can make almost 9 turns before the counter overflow)
<dir>axis direction0 or 11 ascii digit0=increments (up/right), 1=decrements (down/left)

Merlin/Orion commands set

FunctionCommandResponseNote
Read axis positionj<axis><pos>|
Read axis statusf<axis><s1><s2><s3>
Stop movingL<axis>
Init (at switch on)F<axis>
F<axis>
a<axis>
D<axis>


D3620E
F90600
Start movingL<axis>
G<axis>3<dir>
I<axis>220000
J<axis>



220000 seems to be the divider for the speed...
Drive to position

Model

View

Distributing

Make Debian package

Papywizard includes an distutils extension script to build debian package in a easy way:

$ python debian/setup.py bdist_debian

The package is build in the dist/ directory.

Make Maemo package

Same for debian package:

$ python maemo/setup.py bdist_debian

Make Windows installer

This is a little bit tricky (as always on this plateform!).

You first need to build the executable, by launching the windows setup script. The easier is to use Ipython:

In [1]: run windows/setup.py py2exe

Then, run the script windows/papywizard.nsi (need to install NSIS software) to build the installer itself.

The future

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