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1  International / Deutsch / Re: Wie ein LCD ansteuern ; LMC 1602 I2C ; Tutorial ; Sketch on: Today at 04:55:28 pm
Ich bin mir da nicht sicher, korrigiert mich da bitte falls ich falsch liege,
aber ich denke, dass dieses LCD Display einfach ein ganz normales LCD ist, wo einfach bloß ein I2C Portexpander
(oder sowas in der Art) dran ist.

Das ist genau so. Da aber die Verdrahtung vom I2C Portexpander zum Display von Modul zu Modul etwas unterschiedlich gehandhabt wird, hat der Bibliotheksprogrammierer einfach diese Art der Festlegung gewählt. Man muss dann für das eigene Modul herausfinden (gut wenn der Verkäufer auch ein Datenblatt bereithält), welcher Ausgang des I2C Portexpanders auf welchen Display-Pin geht.
2  International / Deutsch / Re: WIFI+UDP+NTP keine Verbindung on: Today at 04:47:34 pm
zu1. Nein sehe ich nichts.

Dann bezweifle ich, dass die Verbindung über die Fritzbox geht. Wenn das Tool funktioniert und einen Zeitwert liefert, aber auf der Fritzbox keine Pakete durchgehen, dann hast Du womöglich eine falsche Vorstellung, wie Dein Netzwerk aufgebaut ist.

zu 2. ich bekomme auch kein TCP hin. Nix ist erreichbar. Nur in meinem Netztwerk ist das shield sichtbar. Auch wenn ich das Shield als Webserver laufen lasse, ist die IP des Shields  aus meinem netzwerk nicht erreichbar.

Was heisst sichtbar? Kannst Du den Arduino anpingen? Ich fürchte, wenn sowohl TCP als auch UDP nicht gehen, liegt das Problem komplett anderswo und so aus der Ferne würde ich auch auf die Fritzbox tippen, allerdings sind das im Normalfall sehr zuverlässige und einfach zu konfigurierende Geräte. Wenn Du das Teil also nicht komplett verkonfiguriert hast, sollte das schon hinzukriegen sein.
Versuche ein Notebook mit WiFi aufzutreiben, damit Du dort direkt den WLAN-Verkehr sniffen kannst und sehen kannst, was die Fritzbox auf die Anfragen des Arduinos zurückgibt.
3  Using Arduino / Project Guidance / Re: Possible problem using DS1307 RTC while using emonTx Arduino Shield on: Today at 04:39:21 pm
So just to confirm, can´t I use those inputs instead of A4 and A5? After some research I've read that SCL and SDA are/were used for I2C, and that was previously done using the A4 and A5 pins.

The SDA/SCL pins are directly connected to A4/A5 on the Arduino Ethernet board. The additional pins are there to extend the compatibility with the different Arduino board types. So you can use the SDA/SCL pins with a shield and on the UNO (and Ethernet and some other types) they are connected to A4/A5, on the Mega2560 they are connected to D20/D21 and on the Due/Leonardo they are separate pins that are not used otherwise.

BTW: SCL is solely an output on the Arduino (in your usage), while SDA is an input as well as an output, that depends on the current state of the I2C communication.
4  Using Arduino / Sensors / Re: wiring up a sharp GP2Y0A02 distance sensor on: Today at 04:33:24 pm
You mention calibrating... how would i do that?

That's easy: put a big obstacle in front of the sensor, read the value it puts out and measure the distance manually. Do this for several distances and use that as the reference table.

as far as point b is concerned, perhaps the arduino analog input is also converting the numbers it receives some how?

The Arduino is not receiving the numbers, it's measuring them. The value you get is telling you that that many times a 1023th of the reference voltage (if you've not chosen something different explicitly, that's the voltage you're powering the Arduino with) is currently present on the analog input pin. The problem here is that if you're powering the Arduino by USB this voltage may vary over time so you don't get really usable values (although you might get a trend in any case).

I'm trying to compare this number with the chart on page 3 under the "Electro-Optical Characteristics section".

I don't have a chart there, just a table.

How am i supposed to understand the line that has the parameter "Output Voltage"?  does it mean that if I measure 0.4 volts on the wires, then value i get should be divided by 150?

No, it means, if you get a value of 82 (which equals 0.4V if you power with a stable 5V) the obstacle is about 150cm away. But as you also can see there, that value can be in the range between 51 (=0.25V) and 112 (=0.55V). That's why I told you that you might have to calibrate by looking what your sensor is giving you at that distance. If you look at page 4 you can see the curve that describes the relationship between the measured voltage and the distance the obstacle has from the sensor. The calculation is not done by a simple division. If you want a realistic value you have to do at least a square approximation.

It'd be nice to get the algorithm correct for learning purposes and for being able to control my robot with accuracy...

I don't know if that's the right sensor if you want accuracy for your robot.
5  Using Arduino / Sensors / Re: wiring up a sharp GP2Y0A02 distance sensor on: Today at 10:43:20 am
According to the datasheet anything closer than 20cm is not detected correctly but recognized identically as a far away target.

The read value is not in cm it's just a voltage level. The highest value is at about 510 when the obstacle has a distance of about 20cm. At 50cm it's around 350 and from about 130cm the value stays more or less at approximately 100. (See Fig.2 on page 5 of the datasheet). That curve is not linear, so it's not an easy calculation to get a distance in cm out of that sensor and it probably has to be calibrated first. Do you need absolute values from the sensor? Isn't it enough to know when it approaches an obstacle?
6  Using Arduino / Sensors / Re: IR Pulse Sensor Help on: Today at 10:26:22 am
I don't know how exactly this sensor works as the don't provide schematics for it (and we see again, that you should never buy anything from a supplier that doesn't provide datasheets or equivalent documentation for their products).

I guess that the LED emits some light that goes through your finger and the sensor detects how much of it went through. That value probably changes in the rhythm of the heart beat. Have you tried covering the sensor and your finger in it so that no sun or synthetic light is reaching it? I would expect the sunlight not to have a high impact but synthetic light has. Usually these kinds of sensors are in a kind of part-finger-glove to keep away external light sources.
7  International / Deutsch / Re: Hilfe bei IR-Codes senden… on: Today at 10:18:35 am
Du müsstest die Bibliothek anpassen und aus dem "unsigned long data" im Methoden-Kopf ein "uint64_t" machen. Der Rest des Codes könnte dann schon funktionieren.
8  Using Arduino / Networking, Protocols, and Devices / Re: Wire not working on Due? on: Today at 10:10:11 am
The Due apparently has internal pull-ups on SDA(20), SCL(21) as I can measure 3.3V on the pins. Yet when Wire.begin() is called out it (communication to my RTC module) does not work.

The Due has such pull-ups (1k5 according to the schematics) on pin 20 and 21 and it doesn't have on SDA1 and SCL1.
A 10k pullup is probably too weak if the bus is more than a few centimeters long, don't forget it goes to 3V3 and not 5V.

What do you mean by Wire.begin() is working or not working? Wire.begin() does not communicate with your RTC module, it just configures the hardware that the TWI module will be used.

I ask again for a wiring diagram.
9  International / Deutsch / Re: Hilfe bei IR-Codes senden… on: Today at 07:54:12 am
Habe ich das richtig erraten? Du hast 2 Arduinos, einen benutzt Du zum Senden, den anderen zum Empfangen. Du schaust zuerst, was der empfangende als Resultat der Ansteuerung mit der Fernbedienung ausgibt und programmierst den anderen Arduino dann so, dass er diesen Code versenden soll. Mit dem empfangenden Arduino wird das gesendete Signal wieder dekodiert und da bekommst Du ein anderes Resultat als erwartet. Stimmt das soweit?
10  Using Arduino / Sensors / Re: IR Pulse Sensor Help on: Today at 06:30:05 am
This might be because I am placing my finger in the wrong place? or could be a problem with my code/ circuit.

Your finger should be placed between the LED and the sensor plate below it. If you did that correctly and the sensor works, the LED on pin 13 should blink at each heartbeat.

In the serial monitor you should get positive and negative values alternating in about the same rate as your heart beats.
11  Using Arduino / Networking, Protocols, and Devices / Re: Explaining a-, synchronous, SPI, I2C, TWI, 2/3 wire interface, Serial TX/RX on: Today at 06:22:05 am
I2C is asynchronous as there is only one data line. You cannot transmit and receive data at the same time like you can with the SPI & UART interfaces.

Synchronous is not the same as duplex or bidirectional. I2C is synchronous because the clock signal synchronizes the two communication partners but it's not fullduplex, it's a synchronous halfduplex communication.
12  Using Arduino / Project Guidance / Re: Multiple LEDs with analogue output on: Today at 04:16:12 am
Here is the sort of thing but instead of on/off control I'd like to set the voltage.  I'd guess some sort of programmable chips exist but I'd prefer a solution that is wholly controlled from the Arduino's pins.

The Arduino (at least the basic types as the UNO) don't have an analog output where you can set a voltage. The "emulate" such an analog output using PWM (pulse width modulation) which means the turn a digital output on for some time and then off again for some time in quite a fast manner (several hundred times a second). That's a perfect way to dim LEDs because the human eye won't notice the fast on/off switching and get fooled to see a dimmed brightness value.

What kind of Arduino are you using? What LED devices are you talking about (links)? Do you want to dim them all together or each individually? You won't be able to control all devices with just the Arduino itself, you'll need some external hardware to provide enough power to the LED devices.
13  Using Arduino / Networking, Protocols, and Devices / Re: Explaining a-, synchronous, SPI, I2C, TWI, 2/3 wire interface, Serial TX/RX on: Today at 04:08:10 am
The address can be found out with a utility code.

Can be found is correct, but usually you look that up in the datasheet.
I2C has the additional advantage that by design you're able to connect devices with different voltage levels (5V and 3V3) to the same bus without destroying them because the lines are pulled up by resistors and not actively by the master or slave devices.

COM port style TX/RX line pins that run at 5V while PC com port runs at 12V.

PC (better RS232) has +/- 3-12V, the negative levels are usually the bigger problem than the voltage but you should never connect TTL UART devices directly to RS232, that's correct. This interface is asynchronous which means that the timing is more critical. UART allows two way communication (bidirectional) with just two wires (they're usually counted without the power wires Vcc and GND). Using chips as the MAX485 you can use these UART ports to communicate with RS-485 devices (used in ModBux for example).

I2C has two defined speeds (100kHz and 400kHz), SPI usually is much faster with speeds in the MHz range while the UART interface usually is the slowest variant with common speeds in the 1-100kHz range (although i can go higher up to some MHz).
14  Using Arduino / Networking, Protocols, and Devices / Re: Is it possible to communicate the smartphone (Android) and the Zigbee module on: Today at 03:50:06 am
Is your smartphone able to be a USB host (most are not), what ZigBee module are you using (the usually don't have USB interfaces)? How is that question related to the Arduino platform?
15  Using Arduino / Networking, Protocols, and Devices / Re: Wire not working on Due? on: Today at 03:47:29 am
Provide a wiring diagram. I'd guess that the problem is on the hardware side but that's currently just a wild guess.
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