Hot answers tagged

12

At least in the microcontroller level: Serial ports (usually TTL or LVTTL) are still the most common way to communicate, since most simple microcontrollers don't have a USB controller. For instance: most 8-bit AVR or PIC microcontrollers don't have USB, a few 32-bit ARM microcontrollers do, but they all usually have serial ports. Conversion from TTL/LVTTL ...


9

Simplicity, i guess. A USB implementation (chips and driver software) is usually more complex than good ol' RS232, which can even be found in many 8-bit microcontrollers. While USB has many protocol mechanisms and is designed to deal with many participants over a bus, a RS232 connection doesn't have any of that. Instead, it's the "rawest" form possible of ...


5

I think the biggest reason that RS232 has stayed around is the simplicity in implementing common use-cases in embedded hardware - like sending a sequence ASCII bytes between two devices for control. The use-cases for sending information at the much higher speeds available with USB are not worth the trade-off in complexity caused by implementing the USB ...


4

Simplicity for hardware designers and easy usage for programmers Reliability Well known and supported in many systems Specially in robotics when we forced to use USB instead of RS232 (Our new PCs did not have RS232 ports). We faced many problems: Any USB socket disconnection need so much effort to recover the system. Sometimes it leads to a bad system-...


4

Sure, here are a couple of choices for you: For high end, you can look at a 200 counts per revolution rotary encoder like this one: $30 Sparkfun 200 Counts Per Revolution Rotary Encoder You'll need a microcontroller like an Arduino to count the rotations, there's some sample code to play with. $5 Adafruit 24 Counts Per Revolution Rotary Encoder Cheaper, ...


4

There is a bug in the implementation of sleep/wakeup on Create 2 which was fixed in release-3.8.2 for robots with an older processor, or release-stm32-3.7.7 for robots with a newer processor. To receive a code update that will (hopefully) fix your issue, please e-mail create@irobot.com, referencing this post. Please note that while I'm an iRobot employee, ...


3

I would like to suggest you to use Beaglebone Black , it is smaller than size compared to Raspberry pie. It is just the size of a credit card. And has a faster processor of 1 GHz and has an inbuilt 3D graphics Accelerator. There is already a Cape Board for BBB that supports HD Video sensors. Update : And if you want to use OpenCL then I would suggest you ...


3

Beaglebone USB When you plug a USB cable between the USB B plug of the Arduino Uno and the USB A plug of the Beaglebone Black, the Beaglebone should be able to talk and listen to it the same way any other Linux distribution talks and listens to any other CDC class USB peripheral. On the Beaglebone, a CDC class USB peripheral can be read an written to ...


3

What you are looking for is called serialization. Serialization is the process of creating a string (a serial stream of data) (not necessarily NUL-terminated) from arbitrary data. The issue serialization addresses is the fact that the same data are represented in different computers differently. For example, take this struct: struct A { unsigned int x; ...


3

What you want cannot be simply done by using an Android device and a USB cable. You will need a micro controller to process the instruction sent from your mobile device and then control the motor movement. The android device will communicate to the arduino using say Bluetooth(although there are many other alternatives you can select), the arduino will ...


3

Yes this is pretty easy to solve, you just need basic soldering skills. Just open the cables of your additional USB-devices, you will see 4 wires. 2 of them are for the data, just leave them. The other two are for powersupply, just connect them to your 5V power supply. But make sure you have to right ones, otherwise your device will start producing magic ...


3

Yes, it is possible. You need the Android Accessory API and Android Accessory Development Kit. It is based off Arduino, and is open. In general, if the phone + the ADK is cheaper than buying the components separately (I suspect it would be), then I'd buy the phone + ADK. Your other option is to buy a phone, and a bluetooth shield for a microcontroller, ...


2

Maybe you could take one from an old computer mouse, and count the light pulses directly from the mouse board so you could tell the length of the cord.


2

Communication latency is another reason why USB1.1 or USB2.0 is not always a good replacement for RS232. Data on USB1.1 or USB2.0 bus is formatted into 1ms or 125us frames respectively, which forces minimum receive to transmit latency equal to two frame periods (often more in practise). This is an important consideration for modern PC hardware, which usually ...


2

There have been some projects that allow you to run NXT programs on a computer, like this one: http://ocaml-mindstorm.forge.ocamlcore.org/ However, this is done by downloading and running a different program on the NXT, which acts as a communications bridge -- passing control to and from the main computer. There are probably other libraries that use this ...


2

I don't know how it would be specifically in Python, but generally speaking, when you open a file, you get a handle which you may possibly write to or read from. Again, generally speaking, the read and write system calls return the number of bytes they have read or written. In your case, you are writing "VER\r" to serial port. You get 4 because all four ...


2

ser.write is always returning number of bytes written. It is not the response to your command. In order to get the response, you need to perform a read command.


2

Use a self-powered hub. Look at the power adapter from the mains (220v). In almost all instances, it is converting 220vac to 5vdc (sometimes 5vdc and rarely 12vdv). Cut the power adapter cable to the hub in half after determining which half of the cable pair is negative and which is positive (see picture below). Often it's as obvious as the red wire is ...


2

Whilst your question would be better suited to the Arduino StackExchange site, I shall attempt to answer it nevertheless. Below is the method that I have used in the past, however, there are, obviously, more than one way to skin a cat... For example the same question was asked a few years ago on EE.SE, Connect Android device to Arduino Uno via USB. The ...


2

Did you initialize libusb? From the Sourceforge documentation: int libusb_init ( libusb_context ** context ) Initialize libusb. This function must be called before calling any other libusb function. Seems like a trivial thing to ask but I didn't see it in your code, but I also don't see anything blatantly wrong with your code.


2

If it's a FTDI device, download the latest driver from http://www.ftdichip.com/Drivers/VCP.htm I assume its the original USB to Serial cable from iRobot you're using.


2

USB is more than just a connector. It is a standard communications protocol, voltage levels, and even wiring colors. I suggest you get a standard USB cable, cut it in half, then splice in your wires. http://wikipedia.org/wiki/USB does a good job of describing the pin outs on the various USB connectors.


1

You just need a DC-DC converter. This will take care of stepping down the voltage from battery to USB power specs. You may buy the ICs online and solder them or look for a breakout boards for quick setup. Alternatively, you can look for USB car chargers or LiPo BEC (Battery Elimination Circuit). You can break open the Car USB charger (which has the cigar ...


1

Other possible source of electronics for such applications are pololu, adafruit, and sparkfun. All three of them offer all sorts of motor controllers, servo controllers, sensor interface boards, etc.


1

you dont need to do the soldering for the cypress processor, there are always sdk boards like http://www.cypress.com/?rID=58321 or really just get something like http://www.e-consystems.com/UltraHD-USB-Camera.asp browse e-consystems site and you will find something usefull


1

Thank you for directly linking to the manual -- that makes answering questions like this much quicker. I connected the instrument to my computer using a D-sub/USB conversion dongle. I'm assuming that you've already figured out that the thing that looks like a standard 9-pin D-sub connector on the Harvard Model 33 is completely incompatible with ...


1

First, ensure that your wiring is consistent with the wiring diagram on p. 24-25. I've seen similar "random" behavior when the grounds are not connected properly. Before attempting to programmatically talk to the pump, try it manually. I use TeraTerm to talk to my Harvard 33 during testing - but any like terminal software will do (even Hyperterminal). ...


1

After reading AVR and CrossPack docs, I've found really easy to do this. For AVR development environment setup, do the following thing: Install xCode on your Mac, choose latest version. Now install CrossPack. This will do all the environment setup. CrossPack installs required libs to support USBasp as well. To create project using xCode: Create new ...


1

you can pyusb for send data http://pyusb.sourceforge.net/docs/1.0/tutorial.html and your data information is here http://www.torobot.com/down/usc_en.pdf i think you python code like this import usb.core import usb.util # find our device dev = usb.core.find(idVendor=0xfffe, idProduct=0x0001) # was it found? if dev is None: raise ValueError('Device ...


1

I think you're asking whether you can use a USB-to-serial adapter to enable you to connect a USB webcam to a serial-to-wifi converter. The answer to that is no, unfortunately. USB defines a hardware interface and a communications protocol. Your webcam driver communicates with the physical webcam by sending image data over USB, and your USB-to-serial ...


Only top voted, non community-wiki answers of a minimum length are eligible