Planet maemo: category "feed:dff3398e3342941be010827a35a8ef95"
Unfortunately nokia refuses to fix bug in USSD realization without any explanations. So I have to continue supporting my dirty hack.
I'm currently in a process of making UI for bike computer and I would like to know your opinion about it's usability.
Four types of elements can be placed on display: clock, current speed, counters and graphs. The most interesting ones are counters. They store information about distance, average, maximal and minimal speed and about time spent for riding.
Some time ago I've written about software support for bike speedometer for n900. It was proof of concept CLI realization in Python. Now firs beta of normal application is available. It was rewritten in C++, which decreased CPU usage by four times. For the beginning speed, trip distance, average speed, average speed in last 5 minutes and clock are supported. So this is already a usable solution. Now the main question is "How many people are interested in this and why n900 can be better, than usual bike computer?"
Today I've found some time to write a draft version of software part for a bike speedometer. As far a I could found a good example for getting data from microphone using GStreamer in python, this version is written in python. Now I know that this approach works and I know what tools are needed, so I can write a complete app.
USSD are widely used for communicating with mobile operators: receiving information about balance, prepaid minutes or megabytes left. They were introduced in 1990's and a way they are accessed remains the same. Every time when user wants to know his balance he has to enter unintuitive code to get a message for a short period of time. USSD-widget introduces new usage pattern, which minimizes number of actions needed to make a query to bare minimum, which allows better balance control. This is useful because mobile operators tend to steal money in a hope that users won't notice it.
GPS is good, but it's accuracy is not suitable for measuring bike speed. In this post I'll tell you how to make bike speedometer. It doesn't require any special skills and hardware, only basic soldering skills and soldering iron. This post describes only hardware part, because software is not ready yet, through it is definetely known, that it is not hard to write it.
Currently there are two free navigation applications for n900: mapero and navit. Both are using text to speech syntheses for voice navigation. This problem is solved more or less well for English language, but problem of Russian speech syntheses is much more complicated. It is supported in espeak and festival (launching festival on n900 is another story) but espeak speech quality is wery poor. You need too much attention to understand what it is saying, so it is not suitable for voice navigation. Festival with voice developed in MSU is good, but requires about 130 MB of RAM at moments of synthesis. n900 has 256 on board, so festival is very slow and it takes about 30 seconds to generate a phrase. Not suitable too.
This version fixes old bug with missing python-dbus dependency (the only known to me bug in previous version) and adds some dbus interfaces to widget. It can be useful if you switch on and off some services with USSD codes.
To use them you firstly need to know widget id. You can read it in the header of settings dialog (ussd-widget.desktop.0 is the name of the first widget on your desktop).
I think you wouldn't be pleased if some unimportant call or, what is much worse, SPAM SMS message wakes you up. Solution would be to switch silent profile when you sleep. You can do it by hand ever day, but why not to automate it? You can use silencer, but it has very simple logic, which silences phone when it is late, but not when you sleep. What about something more intelligent?
Today many devices we use in everyday life are called "smart". What does it mean? Electronics (at least now) can't be smart, so we speak about intelligence imitation and following rules can be used for measuring its quality:
- Device should do what user wants
- If device doesn't obey user, it must tell user why it doesn't obey in such a way, that user would agree, that he was wrong. This is user misstakes control.
- Device should guess, what user wants, if possible.
Some operators return balance in SMS messages instead of USSD replies. Now USSD-widget can rule this out. Changes:
- SMS listener
- RegExp groups can be used in parsers
People in this thread have found out, how to add dbus listener, which would be triggered on incoming SMS. But SMS is encoded in-to a PDU string so it has to be decoded first. I've added support for this in-to latest (0.0.9) gsmdecode.py from ussd-comon package.