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1  Using Arduino / Networking, Protocols, and Devices / Re: Poor Man's 2.4 GHz Scanner on: January 27, 2014, 11:23:06 am
Thanks for your comments. The colors were added in the inital example just for marking the different 2.4GHz component seen. Of course there are no colors available in the terminal prg of the Arduino IDE.

The amount of power in each channel is displayed in ASCII grey scale. This is an old technique from the time when lineprinters were the primary output of mainframe computers. Have a try on your favorite search engine to find out more (here's one link which came up http://paulbourke.net/dataformats/asciiart/).

There is no reason why the code should not work with current Arduinos as the code uses only standards. I have however no way of testing the UNO or newer devices - I do not own any of these.

In case you have doubts, try any of the newer RF24-libraries. Most of them feature a scanner example based on my old code. These libraries are pretty much up-to-date.

In any case - have fun!
2  Using Arduino / Installation & Troubleshooting / Re: Leonardo RX and TX LEDs are always on! on: March 10, 2013, 03:17:25 pm
- I had an old version of this board lying around for some time. Never got it to work nicely with the old Arduino IDEs...

As it was one of the first boards, it still had an outdated bootloader on board. Flashed now with the 1.5.2-IDE the new Leonardo-bootloader and encountered the same problem you are describing here: TX and RX pins are always "on". As these guys are quite bright on that board, that's kind of annoying...

Well, the solution turned out to be simple: change the board type in the Arduino IDE to "Micro" (just below the Leonardo-listing). The first time you upload code, the board will reconnect again, your OS (I have done this under WinXP) will detect a "Micro", requesting to install new drivers. Do this. This will get the TX and RX leds into the right mode, i.e. only signalling traffic, not constantly "On".

Note that the serial port the device is attached to will change during this procedure. Check your device manager for the new port and set it correctly for further uploads.

So in summary: seems that the IDE has some issues here - when the IDE thinks it talks to a "Micro", everything is ok. When it thinks it talks to a "Leonardo", the TX and RX LEDs of the Olimexino stay always on.

I have not checked whether the Leonardo bootloader is different from the Micro bootloader and what the IDE is doing differently. But with my board has still having the Leonardo bootloader "on board", selecting "Micro" as board works fine.

Best, cpixip.
3  Using Arduino / Sensors / Re: ARDUINO - SONAR I/O CARD AND 4 SENSOR on: March 20, 2012, 11:29:58 am
hmmm - I thought that I indicated that the solution you are searching for requires some additional, not so trivial work both hardware- and software-wise, and that you are better off by using standard ultrasonic sensors which have been described extensively on Arduino's playground and many other places on the web. These new sensors are easier to use and will give you much better results than the old Cybot-stuff.

For that reason, frankly, I doubt you will find anybody here willing to study the schematics of this old stuff and come up with a solution for you. Also, from experience, I also doubt that the WWW will be of any further help to you with this old circuitry - you have already found most references to the Cybot hardware.

So.... - guess you are on your own on that journey from that point on.... smiley-wink
4  Using Arduino / Sensors / Re: ARDUINO - SONAR I/O CARD AND 4 SENSOR on: March 19, 2012, 03:11:18 pm
- these are boards which were used on an old robot kit called "Cybot". How the circuit works is explained in the pages you provided links to. You need to study the other circuits on these pages as well because these "pure" ultrasound board of the Cybot is not operational without additional circuitry (see below).

Anyway - it worked quite well with the Cybot avoiding that the like robot bumped into things.

While these circuits feature a rather interesting design, I would recommend using instead one of the readily available ultrasound distance units - some of them feature even serial or I2C connectivity which makes interfacing them to an Arduino rather painless. These sensors either give you the distance directly in cm or inch, or a digital pulse which duration is proportional to the distance measured.

If you want to use the old Cybot design anyway, I'd suggest studying the linked circuit diagrams in detail. You will need to design a board creating the "ping" for the ultrasound transmitter, as the circuit you linked to is only the receiving part.

As far as I remember, in the original Cybot design the transceivers were driven by a PIC which was also doing the processing. It was claimed that the sensors were able to distinguish between near and far objects, but from the circuit I would rather judge that they are just giving out a binary "something is closeby"-signal. Again, I would rather go for a newer design.
5  International / Deutsch / Re: LSM303DLH an Arudino Pro mini 5V on: July 24, 2011, 02:36:11 pm
Thanks Sirion - as one can see in the image your second link is pointing to, it is really easy wiring.

- cpixip
6  Using Arduino / Sensors / Re: Distance Sensor(plz help) on: July 20, 2011, 03:10:10 pm
well, with the appropriate Sharp IR sensor you can indeed realize a distance mapper. Have a look at this link here:

http://luckylarry.co.uk/arduino-projects/arduino-processing-make-a-radar-screen-part-3-visualising-the-data-from-sharp-infrared-range-finder/

You might also find this thread here http://arduino.cc/forum/index.php/topic,63433.msg461345.html#msg461345 useful.
7  Using Arduino / Sensors / Re: SHARP IR Distance Sensor - GP2D120XJ00F on: July 03, 2011, 02:20:59 pm
oops... - sorry, I mixed up the Sharp IR distance sensors with the Sharp IR dust sensor (the GP2Y1010AU0F for example). The later is being triggered and has to be read out at a specific time after the trigger. Sorry for this confusion....

The Sharp IR distance sensors are indeed outputting the data continously, but that reading does change only at discrete time points.

Back to the issue of power line spikes: I would try to place the capacitors as close as possible to the sensor, not the Arduino. If you google, you will find people soldering a condensator directly to the pins of the IR sensor (for example: http://www.robotfreak.de/blog/en/robotics/how-to-improve-sharp-ir-sensors/450).

You might also try to power sensor and Arduino with different voltage supplies for a test (batteries for example).

Basically, if the power is not stable enough, the noise spikes created by the sensor kick through to the Arduino, especially the Aref voltage which the DAC uses to digitize the analog voltages. If that happens, the readings of the sensor will get noisy, even so the voltage the sensor is delivering is constant.

Time averaging will stabilize the readings, in any case.
8  International / Deutsch / Re: LSM303DLH an Arudino Pro mini 5V on: July 01, 2011, 11:54:35 am
naja, das Photo hatte ich gerade rumliegen. Aber immerhin habe ich ja die wichtigen Kabel beschriftet, sollte also kein Problem sein, die Verkabelung zu reproduzieren. Hier nochmal (vom Anfang des Threads) zusätzlich das Ganze als Textbeschreibung:


  • den "HV" bezeichneten Eingang des Levelkonverters (auf der "HV"-Seite) verbindest Du mit den 5V vom Arduino.
  • an den "LV" bezeichneten Eingang des Levelkonverters (der liegt gegenüber, auf der "LV"-Seite) legst Du Deine 3.3V Versorgungsspannung.
  • Die SDA Leitung vom Arduino legst Du an einen der mit "TXO" bezeichneten Eingänge des Levelkonverters auf der "HV"-Seite.
  • Es ist noch ein "TXO" Anschluss frei (auf der "HV" (high voltage) Seite - dort kommt der SCL-Anschluß vom Arduino dran.
  • Auf der jeweils gegenüberliegenden "LV" (low voltage) Seite stehen Dir dann die entsprechenden SDA/SCL-Signale mit 3.3V an den jeweiligen "TXI"-Buchsen zur Verfügung.


Man beachte, dass der Levelkonverter selber keine GND-Verbindung braucht, um zu funktionieren!

Hoffe, das beseitigt nun alle Unklarheiten... smiley-wink
9  Using Arduino / Sensors / Re: SHARP IR Distance Sensor - GP2D120XJ00F on: July 01, 2011, 11:49:59 am
actually, reading of the sensor value should occur at a precise time after you trigger the measurement. See the datasheet on how the voltage varies over time, there's a diagram somewhere. That time is the 38 msec robtillaart mentioned. You should not have any jitter in that timing. And yes, sampling with a higher frequency does not make too much sense, provided your powersupply is clean.
10  International / Deutsch / Re: Pegelwandler on: June 30, 2011, 01:28:18 pm
Der Pegelwandler bei Watterott ist für genau diesen Anwendungsfall gedacht. Und ja, die Philips Appnote ist da grundlegend - dort ist auch nachzulesen, warum und wie das funktioniert. In diesem Thread (http://arduino.cc/forum/index.php/topic,63665.msg463407.html#msg463407) kann man nachlesen, wie man den Pegelwandler anschließen muß (angehängtes Bild).

Natürlich gibt es viele Möglichkeiten, verschiedene Logikpegel miteinander zu verbinden. Es gibt ICs auf der Basis der Philips Appnote die es erlauben, mehrere I2C-Busse mit unterschiedlichsten Pegeln miteinander zu multiplexen, einfach auch über I2C gesteuert. Man muß halt sehen, was man braucht. Meiner Erfahrung nach sind die Sparkfun-Teile (um diese handelt es sich bei dem Watterott-Teil) für einen Breadboard-Aufbau keine schlechte Wahl.
11  Using Arduino / Sensors / Re: SHARP IR Distance Sensor - GP2D120XJ00F on: June 29, 2011, 12:08:00 pm
Actually, the measurements of a Sharp IR distance sensor are quite stable over time. If you notice jitter in the readings, it is most probably caused by a not sufficiently stable power supply. As I already remarked, these device draw a lot of current when they are firing. Be sure to have sufficient and good capacitors as close to the sensor as possible (ideally a big one for the large power spike, plus a 10nF one in parallel for the high-frequency components).

One the other hand, due to the principle these sensors work with (triangulation), they have a much greater resolution at short distances than on distances farther away. Very similar to human 3D vision which works best at close distances. Any noise you have in the system is basically magnified (distance-wise) if you are working at the upper edge of the distance range.

Note also that these IR sensors tend to work at distances greater than specified, but these measurements might not be as stable as those taken in the specified range.

In working with Sharp IR distance sensors, it is most important that you get the power supply to the sensors right and that you decouple these sensors sufficiently from the rest of your circuit, especially the Arduino. You might want to compare the readings you get with readings when you power the IR sensor with a separate battery.
12  Topics / Device Hacking / Re: Eaglemoss Cybot on: June 19, 2011, 02:29:30 pm
well, I searched my old bookmarks for still active sites, here's another one which I found quite informative:

http://www.adrirobot.it/menu_new/index/index_cybot.htm

(italian, but with Google translate quite useful.)

There should be still some old Cybots around, waiting to be resurrected. Here some other links showing such efforts:


It would be great if you could share any progress in this forum/thread.

- cpixip
13  Topics / Device Hacking / Re: Eaglemoss Cybot on: June 19, 2011, 11:46:08 am
For those people who do not know what that is... : the Cybot was a small robot which could be build from prefabricated parts, sold (I think) on a monthly basis with a magazine.

The final robot featured a own programming environment where simple behaviors like line following, light seeking or object avoidance could be programmed. In the final parts of the series, the robot could seek an IR-emitting ball, catch it and transport it to a goal. It was also able to react to spoken commands via a headset.

Now, there are still some webpages around dealing with the circuits of this little robot; some people reverse-engineered as much as possible, even were able to figure out the PICs used in the design....

Here are are some links to get you started:



Just a few comments: the Cybot featured two quite strong motors; if you have the motor-driver board as well, it is rather easy to connect that to an Arduino. This should make a simple but fast robot base.

Depending which parts you actually have, you could also use the line-sensor of the robot for line-following and the LDRs for light seeking experiments. The Cybot also featured two ultrasound sensors (pairs of transmitter and receiver) - with enough electronic skills, one could reuse these for an home-brew ultrasound distance ranger.

Communication was done via IR, but as far as I know, an own communication protocol is used. Besides communication, IR was also used for beacon location (namely locating the IR-"soccer ball" and the "soccer goal", which featured also an IR-transmitter).

The different electronic parts and PCBs, for example the ultrasound board, are quite ingenious; after all, the designers tried to achieve a maximal effect with a minimum of effort (and costs). The designers used several PICs and discrete circuits in their robot. I think the different modules used something similar to an I2C-bus for communication, but I am not sure.

As remarked, the motor-driver board is a simple H-bridge type design and can be easily incorporated into an own design. The other stuff might be harder to use directly;  people soon started reverse-engineering the Cybot at the time it was published. However, not many people followed the publication all the way through - so there is little information available on parts which appeared later in the series, like the remote control (including a LCD-display) and the speech recognition circuit.

- cpixip
14  International / Deutsch / Re: LSM303DLH an Arudino Pro mini 5V on: June 17, 2011, 11:38:20 am
Hallo Heckmic - nein, kann er nicht. Steht auch nirgendwo, dass er das kann, wenn ich mich nicht irre. Der Levelshifter (insbesondere der von Sparkfun, den ich ja auch in meinem Aufbau verwendet habe) passt lediglich die Logikpegel auf den I2C-Signalleitungen an. Aber er versorgt nicht die am I2C-Bus angeschlossenen Geräte mit irgendeiner Betriebsspannung.

Schaue Dir mal bitte die folgende Philips-Appnote an, in der die Funktion eines Levelshifters beschrieben wird (http://www.kip.uni-heidelberg.de/lhcb/Publications/external/AN97055.pdf), insbesondere die Seite 10 unten. Damit der Levelshifter funktioniert, braucht er auf der 3.3V Seite entsprechende Pull-Up Widerstände, welche die Signalleitung gegen die 3.3V Betriebsspannung ziehen, wenn keine Aktivität auf den I2C-Leitungen ist.

Du brauchst also unbedingt eine externe Betriebsspannung von 3.3V, um den Levelshifter in Betrieb zu nehmen. Wie die angeschlossen wird, habe ich weiter oben beschrieben. Bei Deiner "Beschaltung" bekommt - das hast Du ja selbst gemessen - der Sensor gar keine Betriebsspannung, kann also nicht funktionieren.

Wie gesagt, einen 3.3V Spannungsregel gibt es für wenige Euro in jedem Elektronikladen um die Ecke.... smiley-wink
15  Using Arduino / Networking, Protocols, and Devices / Re: Can I use serial TX/RX to communicate between Arduinos? on: June 14, 2011, 11:30:39 am
- with the use of the NewSoftSerial-library http://arduiniana.org/libraries/newsoftserial/, you can add software-based RX/TX to other digital output pins of your Arduino. So you can even connect multiple Arduinos with each other - or other serial devices, like GPS or a data logger. Works fine.
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