I went and visited Cornell University today – step one of my multiday trip exploring the Northeastern Universities.
Images after the break.
Website Design update!
I’ve been playing around with this design for about a week. Tell me what you think about it?
Arduino Quine
One of the things programmers tend to learn how to do in every language they know is how to write a quine – that is, a program that echoes its own source code out to the user, without reading the source code directly. This is an inherently recursive operation, so language-based tricks are needed to get it to work.
The Arduino is programmed in C++, however, there is no std::cout. Instead, user input is usually through the USART on the Arduino, and as such needs to initialize and print out from that port.
Traditionally, C/C++ quines are written using the preprocessor and the printf command, as it allows for simple replacement of strings with characters, thereby overcoming the recursive operation. As such, I use the sprintf command below (Arduino’s HardwareSerial doesn’t support formatted prints, sadly enough).
Robot updates
So I finally got around to taking some pics of the robot (as it is now):
Mapping FTDI to files with udev
In the course of making a to-be-revealed robot, I’ve encountered problems with various FTDI cables (and their attached peripherals) being automatically mounted in different locations, depending on the order in which they were inserted and initialized. For obvious reasons, this poses an issue – the IMU cable won’t work well with motor commands, and the actuator controller doesn’t give any IMU data.
After some thinking, I decided to solve the problem via udev mounting (somewhat hackish). In Linux, udev controls the mounting of various hardware peripherals to mountpoints in the file system. This tutorial is written for Ubuntu 10.10, but could easily be translated to any distribution of Linux (and probably Mac OS X, as well).