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aas2 3.1 1 = Program LEGO Mindstorms with leJOS and SCCharts =
2
3
4
5 {{toc minLevel="2"/}}
6
7 ----
8
9 == Overview ==
10
aas2 21.1 11 Mindstorms is a product family from Lego, with sensors, motors and a programmable brick. The newest iteration of the product family is the EV3 programmable brick. Its predecessors are NXT and RCX. In the following we will see how to develop applications for the NXT brick.
aas2 1.1 12
aas2 7.1 13 Several open-source, third-party replacements for the offical Lego firmware have been developed. These support many well known programming languages, such as Java, C/C++, Python, Lua, etc. In the following we will use KIELER SCCharts to program Mindstorms running the Lego Java Operating System ([[leJOS>>url:http://www.lejos.org/||shape="rect"]]). Therefore we will first install leJOS NXJ and flash its firmware. Afterwards we will create a simple SCCharts project in KIELER that we will compile and deploy to the NXT brick.
aas2 5.1 14
aas2 3.1 15 ----
16
17 == Download and install leJOS ==
18
cmot 22.1 19 Download and extract the newest archives for your Operating System from [[Sourceforce>>url:http://sourceforge.net/projects/nxt.lejos.p/files/||shape="rect"]] (Linux/Mac) or use the Setup.exe (Windows).
aas2 3.1 20
aas2 7.1 21 The further installation is explained in detail at [[http:~~/~~/www.lejos.org/nxt/nxj/tutorial/Preliminaries/GettingStarted.htm>>url:http://www.lejos.org/nxt/nxj/tutorial/Preliminaries/GettingStarted.htm||shape="rect"]].
aas2 3.1 22
aas2 31.1 23 Do not forget to flash the download leJOS firmware to the Mindstorms brick as explained in the tutorial!
24
aas2 7.1 25 === Known issues ===
aas2 3.1 26
aas2 27.1 27 ==== Linux ====
aas2 17.1 28
aas2 7.1 29 On Linux there is an issue when uploading the firmware because of a kernel module ([[http:~~/~~/ubuntuforums.org/showthread.php?t=1123633>>url:http://ubuntuforums.org/showthread.php?t=1123633||shape="rect"]]). If you can't upload the firmware with your Linux OS, add **blacklist cdc_acm**{{code language="none"}}{{/code}} at the very end of the file **{{code language="none"}}/etc/modprobe.d/blacklist.conf{{/code}}**. Afterwards execute **{{code language="none"}}sudo rmmod cdc_acm{{/code}}**. This will remove the cdc_acm module from the kernel and prevent its restart. Now try to flash the firmware again.
aas2 3.1 30
aas2 17.1 31 Another issue is that the development package of **libusb** has to be installed. On Ubuntu you can do this by using **{{code language="none"}}sudo apt-get install libusb-dev{{/code}}**.
32
aas2 30.1 33 Furthermore, to use USB connection, a java library has to be compiled via **ant**. To do this perform **cd /path/to/leJOS/build** and start **ant**. If the ant build tool is not installed on your system, you can do so via **sudo apt-get install ant**.
aas2 17.1 34
aas2 27.1 35 ==== Windows ====
36
37 The setup.exe of the current LEGO Fantom driver for Windows (1.2.0) has an awkward issue. If you get an error message (Developer Error) because an .msi file could not be found, don't panic. The file is part of the downladed archive (in the Products folder) but you have to start it manually.
38
aas2 30.1 39 ==== Mac OS X ====
40
41 The **leJOS NXJ** tools require a **32 Bit** version of Java. However, newer 32 Bit versions of Java are not longer available for Mac. Thus to use leJOS the installation of **Java 1.6 is required**, which is the last one that supports a 32 Bit mode. You can download the installer for Java 1.6 from [[https:~~/~~/support.apple.com/kb/dl1572?locale=en_US>>url:https://support.apple.com/kb/dl1572?locale=en_US||shape="rect"]]. It will install Java 1.6 to ///System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home// so that the environment variable //LEJOS_NXT_JAVA_HOME//, which is set in the installation instructions, points to the correct path.
42
aas2 33.1 43 The environment variable LEJOS_NXT_JAVA_HOME is set in the installation tutorial by editing ~~/.profile. However, on a Mac the environment variables defined in this file are not visible for GUI Applications, only for apps started from terminal. Thus to use leJOS together with KIELER, one either has to start KIELER from terminal or set the environment variable so that all GUI applications can access it. However, this does not seem to be trivial on Mac (see also [[http:~~/~~/stackoverflow.com/questions/135688/setting-environment-variables-in-os-x>>url:http://stackoverflow.com/questions/135688/setting-environment-variables-in-os-x||shape="rect"]]).
aas2 30.1 44
aas2 3.1 45 ----
46
aas2 7.1 47 == Test the Mindstorm ==
aas2 3.1 48
aas2 7.1 49 A simple Hello World application for the Mindstorms is developed as part of the leJOS tutorial [[http:~~/~~/www.lejos.org/nxt/nxj/tutorial/Preliminaries/FirstProgram.htm>>url:http://www.lejos.org/nxt/nxj/tutorial/Preliminaries/FirstProgram.htm||shape="rect"]]
aas2 3.1 50
aas2 27.1 51 If this works with your device, you are able to start using KIELER to develop applications for the NXT brick.
aas2 3.1 52
53 ----
54
aas2 28.1 55 == Download and Configure KIELER
56 ==
aas2 27.1 57
58 Download and unpack the nightly build of KIELER for your OS. It is available at the [[doc:Downloads]] page.\\
59
aas2 33.1 60 **Note:** Java 1.8 is needed on all operating systems. With Java 1.7 not all plugins of KIELER will be loaded. **Furthermore on Windows**, you will need to download the **32 Bit version of KIELER** – even if you have a 64 bit operating system! Otherwise flashing the brick and uploading to the brick will fail.
aas2 27.1 61
aas2 28.1 62 === The Eclipse plugin for leJOS ===
aas2 27.1 63
cmot 24.1 64 There is an Eclipse plugin for leJOS which adds a project creation wizard and launch configuration to the platform.
aas2 3.1 65
cmot 24.1 66 1. You have to install it via the Eclipse Marketplace (//Help > Eclipse Marketplace...//).
67 OR
cmot 25.1 68 1. Install the plugin manually (Help > Install new Software...). Use the following update site\\
69 11. for NXT: [[http:~~/~~/www.lejos.org/tools/eclipse/plugin/nxj/>>url:http://www.lejos.org/tools/eclipse/plugin/nxj/||shape="rect"]]
70 11. for EV3: [[http:~~/~~/www.lejos.org/tools/eclipse/plugin/ev3/>>url:http://www.lejos.org/tools/eclipse/plugin/ev3/||shape="rect"]]
cmot 24.1 71
cmot 25.1 72 If you have an **NXT** **brick**, install the **leJOS NXJ** Plug-in. If you have an **EV3 brick**, install the **leJOS EV3** plugin.
73
aas2 8.1 74 [[image:attach:lejos_eclipse_plugin.png]]
75
aas2 28.1 76 After the installation, the plugin requires a **little configuration**. Go to //Window > Preferences > leJOS NXJ// (//Window > Preferences > leJOS EV3 //respectively) and enter the base directory of your **leJOS** **installation** in the **NXJ_HOME field**.
aas2 19.1 77
aas2 33.1 78 For EV3, the plugin requires the IP address to connect to the brick (it may work without, but its safer to directly set the name. Reduces headache ). Check **Connect to named brick** and enter the **IP adress** of the brick (displayed on the brick at startup).
aas2 3.1 79
80 ----
81
aas2 14.1 82 == Creating an Example Project ==
83
aas2 33.1 84 The following shows how to create a project, which will turn on a light if a button is pressed.
aas2 14.1 85
aas2 15.1 86 === Create a new project: ===
aas2 14.1 87
aas2 18.1 88 1. Choose //File > New > Project > KIELER SCCharts > SCCharts Project//
aas2 21.1 89 1. In the project creation wizard that opens, select //Mindstorms NXJ// or// Mindstorms EV3// (depending on your brick) as environment and hit //finish//
aas2 14.1 90 1. The project wizard from the leJOS plugin opens. Set the project name to //Flashlight// and click //finish//.
91 1. The project is created and the model file is opened in an editor (This might take a few seconds).
92
aas2 15.1 93 === Edit the model: ===
aas2 14.1 94
95 Change the contents of the model file to the following code and save it.
96
aas2 32.1 97 {{code language="sct" theme="Eclipse" title="Floodlight.sct"}}
aas2 14.1 98 scchart Flashlight {
99
100 @Wrapper TouchSensor, S4
101 input bool button;
102
103 @Wrapper Floodlight, S1
104 output bool light;
105
106 initial state lightOff
107 --> lightOn with button / light = true;
108
109 state lightOn
110 --> lightOff with !button / light = false;
111 }
112 {{/code}}
113
114 This model will start in the state lightOff. If the button is pressed, it will turn on the light and change to the corresponding state, where the light is turned off, as soon as the button is not pressed anymore.
115
aas2 21.1 116 The annotations on the input and output variable are used to define which wrapper code is used to set / read them. **@Wrapper TouchSensor, S4** will set the input variable to true iff the touch sensor on the port S4 is pressed. **@Wrapper Floodlight, S1** on the output variable will turn on the red led of the light sensor that is attatched to port S1 iff the variable is true.
117
aas2 33.1 118 The available wrapper code snippets are defined in the //snippets// directory of the project in ftl files (FreeMarker template files). The table below gives an overview of the available wrapper code snippets.
aas2 21.1 119
aas2 26.1 120 **Note:** The Floodlight of the EV3 has a pretty high latency when switching between on and off.
121
aas2 28.1 122 **Note: **To view ftl files with highlighting, you may want to install the //FreeMarker IDE// feature from the JBoss Tools. However, this is not necessary to work with KIELER. JBoss Tools is available in the Eclipse Market Place and via update site. The update site for Eclipse Luna is [[http:~~/~~/download.jboss.org/jbosstools/updates/stable/luna/>>url:http://download.jboss.org/jbosstools/updates/stable/luna/||shape="rect"]] . Note that only the //FreeMarker IDE// feature is required (Abridged JBoss Tools > FreeMarker IDE).**
aas2 14.1 123 **
124
aas2 15.1 125 === Launch the project: ===
aas2 14.1 126
127 With the mouse over the SCT file in the project explorer, perform //Right Click > Run As > KiCo Compilation.//
128
aas2 21.1 129 A launch config is created, which compiles the model to Java code and creates wrapper code from the annotations in the model file. Afterwards this output is compiled and deployed to the Mindstorms brick, by using the launch shortcut from the leJOS plugin. If any errors occur, you can see them in the Console View.
aas2 18.1 130
131 For a deeper understanding of the project launch and initialization, take a look at the [[wiki page for Prom>>url:http://rtsys.informatik.uni-kiel.de/confluence/pages/viewpage.action?pageId=13762626||shape="rect"]].
aas2 19.1 132
aas2 33.1 133 === Available Wrapper Code Snippets ===
134
aas2 34.1 135 There are several wrapper code snippets that can be used as annotations on input and output variables in the model file. These snippets are inserted in the main file template as part of the project launch. The available snippets are listed below.
aas2 33.1 136
137 For sensors, the port has to be on of S1, S2, S3, S4.
138
aas2 34.1 139 For motors / actuators the port has to be one of A, B, C, D.
aas2 33.1 140
141 |=(((
142 Snippet Name and Parameters
143 )))|=(((
144 Description
145 )))|=(((
146 Use on
147 )))|=(% colspan="1" %)(% colspan="1" %)
148 (((
149 Variable type
150 )))|=(((
151 Remark
aas2 34.1 152 )))|=(% colspan="1" %)(% colspan="1" %)
153 (((
154 Defined in File
aas2 33.1 155 )))
156 |(% colspan="1" %)(% colspan="1" %)
157 (((
158 **Clock,** milliseconds
159 )))|(% colspan="1" %)(% colspan="1" %)
160 (((
161 Sets a variable to true if the time in milliseconds passed
162 )))|(% colspan="1" %)(% colspan="1" %)
163 (((
164 input
165 )))|(% colspan="1" %)(% colspan="1" %)
166 (((
167 bool
168 )))|(% colspan="1" %)(% colspan="1" %)
169 (((
170 See also ResetClock.
aas2 34.1 171 )))|(% colspan="1" %)(% colspan="1" %)
172 (((
173 timing.ftl
aas2 33.1 174 )))
175 |(% colspan="1" %)(% colspan="1" %)
176 (((
177 **ResetClock,** clockVariableName, autoFalse
178 )))|(% colspan="1" %)(% colspan="1" %)
179 (((
180 Resets a clock, such that the full time intervall of the clock has to elapse, before the clock will be set to true again.
181
182 If autoFalse is true, the reset variable will be set to false automatically.
183 )))|(% colspan="1" %)(% colspan="1" %)
184 (((
185 output
186 )))|(% colspan="1" %)(% colspan="1" %)
187 (((
188 bool
189 )))|(% colspan="1" %)(% colspan="1" %)
190 (((
191 autoFalse is true per default.
aas2 34.1 192 )))|(% colspan="1" %)(% colspan="1" %)
193 (((
194 timing.ftl
aas2 33.1 195 )))
196 |(% colspan="1" %)(% colspan="1" %)
197 (((
198 **Time**
199 )))|(% colspan="1" %)(% colspan="1" %)
200 (((
201 Reads the elapsed time since program start
202 )))|(% colspan="1" %)(% colspan="1" %)
203 (((
204 input
205 )))|(% colspan="1" %)(% colspan="1" %)
206 (((
207 int
208 )))|(% colspan="1" %)(% colspan="1" %)
209 (((
210
aas2 34.1 211 )))|(% colspan="1" %)(% colspan="1" %)
212 (((
213 timing.ftl
aas2 33.1 214 )))
215 |(% colspan="1" %)(% colspan="1" %)
216 (((
217 **TickDuration,** targetInMilliseconds
218 )))|(% colspan="1" %)(% colspan="1" %)
219 (((
220 Delays the execution until the tick loop takes at least as long as the given target duration.
221
222 The input variable is set to the actual tick loop duration.
223 )))|(% colspan="1" %)(% colspan="1" %)
224 (((
225 input
226 )))|(% colspan="1" %)(% colspan="1" %)
227 (((
228 int
229 )))|(% colspan="1" %)(% colspan="1" %)
230 (((
231 Should be used on the very first input variable in the model, such that waiting is the last action in the tick loop.
aas2 34.1 232 )))|(% colspan="1" %)(% colspan="1" %)
233 (((
234 timing.ftl
aas2 33.1 235 )))
236 |(% colspan="1" %)(% colspan="1" %)
237 (((
238 **Sleep**
239 )))|(% colspan="1" %)(% colspan="1" %)
240 (((
241 Lets the current thread sleep the time in milliseconds of the variable value.
242 )))|(% colspan="1" %)(% colspan="1" %)
243 (((
244 output
245 )))|(% colspan="1" %)(% colspan="1" %)
246 (((
247 int
248 )))|(% colspan="1" %)(% colspan="1" %)
249 (((
250
aas2 34.1 251 )))|(% colspan="1" %)(% colspan="1" %)
252 (((
253 timing.ftl
aas2 33.1 254 )))
255 |(% colspan="1" %)(% colspan="1" %)
256 (((
257 **Print,** autoReset
258 )))|(% colspan="1" %)(% colspan="1" %)
259 (((
260 Prints a string variable if the string is not empty. If autoReset is true then the string variable is set to the empty string after it has been printed
261 )))|(% colspan="1" %)(% colspan="1" %)
262 (((
263 output
264 )))|(% colspan="1" %)(% colspan="1" %)
265 (((
266 string
267 )))|(% colspan="1" %)(% colspan="1" %)
268 (((
269 autoReset is true per default.
aas2 34.1 270 )))|(% colspan="1" %)(% colspan="1" %)
271 (((
272 print.ftl
aas2 33.1 273 )))
274 |(% colspan="1" %)(% colspan="1" %)
275 (((
276 **DrawString,** x, y
277 )))|(% colspan="1" %)(% colspan="1" %)
278 (((
279 Prints a string to the given x and y coordinate on the LCD.
280 )))|(% colspan="1" %)(% colspan="1" %)
281 (((
282 output
283 )))|(% colspan="1" %)(% colspan="1" %)
284 (((
285 string
286 )))|(% colspan="1" %)(% colspan="1" %)
287 (((
288
aas2 34.1 289 )))|(% colspan="1" %)(% colspan="1" %)
290 (((
291 print.ftl
aas2 33.1 292 )))
293 |(% colspan="1" %)(% colspan="1" %)
294 (((
295 **Button, **buttonId
296 )))|(% colspan="1" %)(% colspan="1" %)
297 (((
298 Sets a variable to true iff the button on the Mindstorms device is pressed.
299 )))|(% colspan="1" %)(% colspan="1" %)
300 (((
301 input
302 )))|(% colspan="1" %)(% colspan="1" %)
303 (((
304 bool
305 )))|(% colspan="1" %)(% colspan="1" %)
306 (((
307 The buttonId has to be one of ENTER, LEFT, RIGHT
aas2 34.1 308 )))|(% colspan="1" %)(% colspan="1" %)
309 (((
310 touch_and_buttons.ftl
aas2 33.1 311 )))
312 |(% colspan="1" %)(% colspan="1" %)
313 (((
314 **TouchSensor**, port
315 )))|(% colspan="1" %)(% colspan="1" %)
316 (((
317 Sets a variable to true iff the touch sensor on the given port is pressed.
318 )))|(% colspan="1" %)(% colspan="1" %)
319 (((
320 input
321 )))|(% colspan="1" %)(% colspan="1" %)
322 (((
323 bool
324 )))|(% colspan="1" %)(% colspan="1" %)
325 (((
326
aas2 34.1 327 )))|(% colspan="1" %)(% colspan="1" %)
328 (((
329 touch_and_buttons.ftl
aas2 33.1 330 )))
331 |(% colspan="1" %)(% colspan="1" %)
332 (((
333 **LightSensor,** port, percentValue
334 )))|(% colspan="1" %)(% colspan="1" %)
335 (((
336 Reads  the value of a light sensor.
337
338 If percentValue is true, the a percent value is retured, based on the light sensor calibration.
339 )))|(% colspan="1" %)(% colspan="1" %)
340 (((
341 input
342 )))|(% colspan="1" %)(% colspan="1" %)
343 (((
344 int
345 )))|(% colspan="1" %)(% colspan="1" %)
346 (((
347 percentValue is not available on EV3
aas2 34.1 348 )))|(% colspan="1" %)(% colspan="1" %)
349 (((
350 light.ftl
aas2 33.1 351 )))
352 |(% colspan="1" %)(% colspan="1" %)
353 (((
354 **CalibrateLightSensor,** port, signal
355 )))|(% colspan="1" %)(% colspan="1" %)
356 (((
357 Calibrates a light sensors high or low values. This means if the variable is true, the current value of the light sensor is taken as its reference high / low value.
358 )))|(% colspan="1" %)(% colspan="1" %)
359 (((
360 output
361 )))|(% colspan="1" %)(% colspan="1" %)
362 (((
363 bool
364 )))|(% colspan="1" %)(% colspan="1" %)
365 (((
366 signal has to be one of High, Low
aas2 34.1 367 )))|(% colspan="1" %)(% colspan="1" %)
368 (((
369 light.ftl
aas2 33.1 370 )))
371 |(% colspan="1" %)(% colspan="1" %)
372 (((
373 **Floodlight,** port
374 )))|(% colspan="1" %)(% colspan="1" %)
375 (((
376 Reads / Sets the state of the red lamp of the light sensor.
377 )))|(% colspan="1" %)(% colspan="1" %)
378 (((
379 input
380
381 output
382 )))|(% colspan="1" %)(% colspan="1" %)
383 (((
384 bool
385 )))|(% colspan="1" %)(% colspan="1" %)
386 (((
387
aas2 34.1 388 )))|(% colspan="1" %)(% colspan="1" %)
389 (((
390 light.ftl
aas2 33.1 391 )))
392 |(% colspan="1" %)(% colspan="1" %)
393 (((
394 **RCXLamp,** port
395 )))|(% colspan="1" %)(% colspan="1" %)
396 (((
397 Turns an RCX lamp on (variable is true) or off (variable is false)
398 )))|(% colspan="1" %)(% colspan="1" %)
399 (((
400 output
401 )))|(% colspan="1" %)(% colspan="1" %)
402 (((
403 bool
404 )))|(% colspan="1" %)(% colspan="1" %)
405 (((
406
aas2 34.1 407 )))|(% colspan="1" %)(% colspan="1" %)
408 (((
409 light.ftl
aas2 33.1 410 )))
411 |(% colspan="1" %)(% colspan="1" %)
412 (((
413 **MotorSpeed,** port, brake
414 )))|(% colspan="1" %)(% colspan="1" %)
415 (((
416 Reads / Sets the speed of the motor in degrees per minute. If the speed value is negative, the motor will drive backwards. If the speed is zero, the motor will actively brake until it stops (brake is true) or remove all power and rollout (brake is false).
417 )))|(% colspan="1" %)(% colspan="1" %)
418 (((
419 input
420
421 output
422 )))|(% colspan="1" %)(% colspan="1" %)
423 (((
424 int
425 )))|(% colspan="1" %)(% colspan="1" %)
426 (((
427 brake is true per default.
aas2 34.1 428 )))|(% colspan="1" %)(% colspan="1" %)
429 (((
430 motor.ftl
aas2 33.1 431 )))
432 |(% colspan="1" %)(% colspan="1" %)
433 (((
434 **MotorIsMoving,** port
435 )))|(% colspan="1" %)(% colspan="1" %)
436 (((
437 Sets a variable to true iff the motor on the given port is moving.
438 )))|(% colspan="1" %)(% colspan="1" %)
439 (((
440 input
441 )))|(% colspan="1" %)(% colspan="1" %)
442 (((
443 bool
444 )))|(% colspan="1" %)(% colspan="1" %)
445 (((
446
aas2 34.1 447 )))|(% colspan="1" %)(% colspan="1" %)
448 (((
449 motor.ftl
aas2 33.1 450 )))
451 |(% colspan="1" %)(% colspan="1" %)
452 (((
453 **MotorRotation,** port
454 )))|(% colspan="1" %)(% colspan="1" %)
455 (((
456 Lets a motor rotate the variable value in degrees. This is only done if the value is unequal zero. If the value is negative, the motor rotates backwards. The variable is set to zero afterwards, such that setting the variable once to a value //X//, will let the motor rotate //X// degrees.
457 )))|(% colspan="1" %)(% colspan="1" %)
458 (((
459 output
460 )))|(% colspan="1" %)(% colspan="1" %)
461 (((
462 int
463 )))|(% colspan="1" %)(% colspan="1" %)
464 (((
465
aas2 34.1 466 )))|(% colspan="1" %)(% colspan="1" %)
467 (((
468 motor.ftl
aas2 33.1 469 )))
470 |(% colspan="1" %)(% colspan="1" %)
471 (((
472 **Beep,** volume
473 )))|(% colspan="1" %)(% colspan="1" %)
474 (((
475 Plays a beep sound as long as the variable is true.
476 )))|(% colspan="1" %)(% colspan="1" %)
477 (((
478 output
479 )))|(% colspan="1" %)(% colspan="1" %)
480 (((
481 bool
482 )))|(% colspan="1" %)(% colspan="1" %)
483 (((
484 default volume is 10
aas2 34.1 485 )))|(% colspan="1" %)(% colspan="1" %)
486 (((
487 sound.ftl
aas2 33.1 488 )))
489 |(% colspan="1" %)(% colspan="1" %)
490 (((
491 **Buzz,** volume
492 )))|(% colspan="1" %)(% colspan="1" %)
493 (((
494 Plays a buzz sound as long as the variable is true.
495 )))|(% colspan="1" %)(% colspan="1" %)
496 (((
497 output
498 )))|(% colspan="1" %)(% colspan="1" %)
499 (((
500 bool
501 )))|(% colspan="1" %)(% colspan="1" %)
502 (((
503 default volume is 10
aas2 34.1 504 )))|(% colspan="1" %)(% colspan="1" %)
505 (((
506 sound.ftl
aas2 33.1 507 )))
508 |(% colspan="1" %)(% colspan="1" %)
509 (((
510 **BeepSequence,** direction, volume
511 )))|(% colspan="1" %)(% colspan="1" %)
512 (((
513 Plays a sequence of tones in either ascending or descending tone frequency if the variable is true.
514
515 The variable is set to false automatically.
516 )))|(% colspan="1" %)(% colspan="1" %)
517 (((
518 output
519 )))|(% colspan="1" %)(% colspan="1" %)
520 (((
521 bool
522 )))|(% colspan="1" %)(% colspan="1" %)
523 (((
524 direction has to be one of Up, Down
525
526 default volume is 10
aas2 34.1 527 )))|(% colspan="1" %)(% colspan="1" %)
528 (((
529 sound.ftl
aas2 33.1 530 )))
531 |(% colspan="1" %)(% colspan="1" %)
532 (((
533 **UltrasonicSensor,** port
534 )))|(% colspan="1" %)(% colspan="1" %)
535 (((
536 Reads the distance that an ultrasonic sensor measures.
537 )))|(% colspan="1" %)(% colspan="1" %)
538 (((
539 input
540 )))|(% colspan="1" %)(% colspan="1" %)
541 (((
542 int
543 )))|(% colspan="1" %)(% colspan="1" %)
544 (((
545
aas2 34.1 546 )))|(% colspan="1" %)(% colspan="1" %)
547 (((
548 ultrasonic.ftl
aas2 33.1 549 )))
550 |(% colspan="1" %)(% colspan="1" %)
551 (((
552 **Gyro,** port, mode
553 )))|(% colspan="1" %)(% colspan="1" %)
554 (((
555 Reads the value of a gyroscope.
556 )))|(% colspan="1" %)(% colspan="1" %)
557 (((
558 input
559 )))|(% colspan="1" %)(% colspan="1" %)
560 (((
561 int
562 )))|(% colspan="1" %)(% colspan="1" %)
563 (((
564 Not available on NXT
565
566 mode hat to be one of Angle, Rate
aas2 34.1 567 )))|(% colspan="1" %)(% colspan="1" %)
568 (((
569 gyro.ftl
aas2 33.1 570 )))
571 |(% colspan="1" %)(% colspan="1" %)
572 (((
573 **CalibrateGyro,** port, autoReset
574 )))|(% colspan="1" %)(% colspan="1" %)
575 (((
576 Resets a gyroscope if the variable is true.
577
578 If autoReset is true, the variable is set to false automatically.
579 )))|(% colspan="1" %)(% colspan="1" %)
580 (((
581 output
582 )))|(% colspan="1" %)(% colspan="1" %)
583 (((
584 bool
585 )))|(% colspan="1" %)(% colspan="1" %)
586 (((
587 autoReset is true per default
aas2 34.1 588 )))|(% colspan="1" %)(% colspan="1" %)
589 (((
590 gyro.ftl
aas2 33.1 591 )))
592
593
594
aas2 19.1 595 ----
596
597 == Using the Remote Console (RConsole) ==
598
aas2 21.1 599 The display of the **NXT brick** is rather small compared to a Monitor. To ease debugging, one can print to a Remote Console (RConsole), if the USB cable is connected. This enables easier collection for example of sensor data.
aas2 19.1 600
aas2 21.1 601 To use the RConsole, **uncomment** the **RConsole** lines in the wrapper code template **Main.ftl**. Start the **nxjconsoleviewer** tool in the bin directory of your **leJOS installation**. Now, when **starting the application**, the brick tries to connect with the nxjconsoleviewer. **Press the //Connect//** button. If connected succesfully, RConsole.println(...) commands will be written to this window.
aas2 19.1 602
aas2 21.1 603 The **EV3 brick** has a similar feature. However it does not require any code changes. Just run the ev3console program in the bin directory of your leJOS installation from command line. The output of the brick will be printed to this command line.
aas2 23.1 604
605 ----
606
607 == Problem Solving ==
608
609 The following presents typical issues and how to solve them.
610
611 |=(((
612 Issue
613 )))|=(((
614 Typical Error Messages
615 )))|=(((
616 Description
617 )))|=(((
618 Solution
619 )))
620 |(((
621 leJOS EV3 does not support Java 8
622 )))|(((
623 "java.lang.UnsupportedClassVersionError"
624
625 "unsupported major.minor version"
626 )))|(((
627 You compile the sources in your project with Java 8 and upload them to the brick. However the lejos EV3 does not support Java 8
628 )))|(((
629 Go to the project properties and switch to Java 7 (Right Click on project > Properties > Java Compiler > Compiler compliance level)
630 )))
aas2 31.1 631 |(% colspan="1" %)(% colspan="1" %)
632 (((
633 Uploading to the brick does not respond
634 )))|(% colspan="1" %)(% colspan="1" %)
635 (((
636
637 )))|(% colspan="1" %)(% colspan="1" %)
638 (((
639 You compile a file successfully and when uploading the result, the connected brick is found. Anyway the upload does not terminate and does not react.
640 )))|(% colspan="1" %)(% colspan="1" %)
641 (((
642 Flash the brick with the current leJOS firmware. If the brick is recognized correctly and the attempt to upload a compiled file fails then the firmware on the brick might be outdated.
643 )))
644 |(% colspan="1" %)(% colspan="1" %)
645 (((
646 Compilation and uploading works from command line but not when using KIELER
647 )))|(% colspan="1" %)(% colspan="1" %)
648 (((
649 This Java instance does not support a 32-bit JVM. Please install the desired version.
650 )))|(% colspan="1" %)(% colspan="1" %)
651 (((
652 You can compile and upload code to the brick using the command line tools but when using KIELER an error message apprears because Java does not support 32-bit JVM.
653 )))|(% colspan="1" %)(% colspan="1" %)
654 (((
655 Set the LEJOS_NXT_JAVA_HOME environment variable, such that it points to an 32-bit JDK and is visible for GUI applications (or at least KIELER). The process to do so differs on every OS. As alternative, execute KIELER from terminal.
656 )))
aas2 32.1 657 |(% colspan="1" %)(% colspan="1" %)
658 (((
659 Brick does nothing after program finished and prints "Program exit"
660 )))|(% colspan="1" %)(% colspan="1" %)
661 (((
662
663 )))|(% colspan="1" %)(% colspan="1" %)
664 (((
665 A program was uploaded and finished without errors. Afterwards the brick prints "Program exit" but does not open the main menu.
666 )))|(% colspan="1" %)(% colspan="1" %)
667 (((
668 This is normal behaviour if uploading a program in debug mode instead run mode (//Debug As// instead //Run As// in Eclipse). To get back to the main menu, press the ENTER and ESCAPE button of the brick at the same time.
669 )))
aas2 23.1 670
671
672
673
aas2 33.1 674
675 input