Updates
Below you will find updates and errata corrections.
Chapter 1
- Pages 7-8. The RIS 1.5 does not contain an RCX 1.5 brick. It contains an RCX 1.0 brick without an A/C adapter port.
- Page 53. Brake mode uses little or no battery power. The technical explanation is as follows: The motors are accessed via H-bridge. Braking the motor is accomplished by a short-circuit between both motor pins. (You can test this with a motor.) The braking effect is produced through the attempt of turning the motor-axle. The motor generates an electro-motive force with an opposite sign to the axle-motion. So, the only power consumption consists of what is added to the motor-axle and not from the power-supply. (Explanation courtesy of Claude Baumann.)
- Page 54. The Prgm button selects the program, not View.
Chapter 2
Page 80. legOS currently allows floating point operations.
Chapter 7
- Page 235. A loop needs to be added to the end of the main() method: for(;;);
- Page 236: A loop needs to be added to the end of the main() method of both programs on this page: for(;;);
Chapter 8
Pages 280-281. The code for robots that use Navigator classes is highly interchangeable, however since Trilobot uses two bumper sensors and Tippy Senior uses only one sensor, the code must be altered slightly. To fix this, remove the LeftBump and RightBump objects, then replace them with a single Bump class that uses input S2 instead of S1 and S3.
Chapter 11
- Some changes have been made to the leJOS communications API:
-
- josx.platform.rcx.comm has been changed to josx.rcxcomm.
- pc.irtower.comm has been changed to josx.rcxcomm.
- RCXDataPort and PCDataPort have both been changed to RCXPort.
- The RCXPort() constructor throws an IOException.
- For specific changes, please see the source code for Chapter 11.
- Pages 425 to 426. You do not have to install the Javacomm API. The new version of leJOS contains native methods to handle communications with the USB and Serial ports. The PC side JAR file must be placed in the classpath, however. Please consult the leJOS readme for full leJOS Comm API installation instructions.
