# Tag Info

6

You can use an external onmidirectional wifi antenna, like these on ebay. If your wifi chip does not have a U-FL connector, you can use a SMA to U-FL adapter or directly a SMA Antenna.

3

To access your RPi over the WiFi, you can use any SSH client like PuTTY. Once you have established a connection between your RPi and computer, then you can control GPIOs through a TCP connection. Use Socket Library in Python for this. You have to set a static IP for your RPi though, and use it in your code. Hope it would help.

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You are confused by the "channels" term here. The resource you are linking to is talking about "conventional" remote control, using it's own frequency and it's own protocol, not compatible with WiFi in any way. In this case the term "channel" means just a specific radio frequency the control is operating. When talking about WiFi, the channels are frequencies ...

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Yes. Sure. We've been doing this long time. ROS is not an "OS" and it's not big. It's just "middleware" which runs well in "Raspbian". We just burn with the official Raspbian(so we hope it can make us work on a "stable" environment) and compile the ROS with source. Here's the step-by-step link(for ROS Kinetic): http://...

2

There is a product from Pololu called the Wixel. In a classroom environment, when one of them transmits a signal all of the others will receive the message. The radio interconnections between the wixels are essentially just like serial communications. It wouldn't be too much work to bash together a protocol that can either 'broadcast' to all devices in the ...

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LEXAN has low absorption and reflection to WiFi as long as not touching say a dielectric antenna where it might shift tuning but unlikely in your situation.

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Have you taken a look at LeJOS? It's a port of the Java VM and SDK to the various Lego MINDSTORMS robot kits. The Lego kits themselves are quite capable as hobbyist robotics kits go, I bought the NXT version years ago and had a lot of fun with it. The newest EV3 kit has a powerful ARM CPU and an SD card reader for loading software, it looks like a good ...

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HTTP is a request reply communication. This is inherently limited to only one of the parties (the client) to initiate the exchange of messages. Furthermore as it is defined at the upper layers of the OSI stack it has more overhead, then protocols on lower layers. One alternative a protocol on the transport layer, like TCP, SCTP or UDP. TCP opens a ...

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There is a project called ROSpberry Pi you can check out. And a company in Pasadena called Acrobotic is now selling SD images of ROSpberry pre-installed.

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The easiest way is to set up a new router that is not connected to the internet. This gives you an isolated network that only local devices can see and connect with. You can even hide the SSID so it can be even more private. This requires the expense of purchasing a new router but has the advantage that you can use a router with multiple high gain antennas ...

1

Another alternative are robots based on the Raspberry Pi or Arduino microcontrollers. The Pi4J library implements convenient API's for accessing Raspberry Pi I/O's, while the JArduino distribution enables controlling Arduino boards from Java over a serial or Bluetooth connection. You can search for "arduino robot kit" or "raspberry pi robot ...

1

The idea is very interesting, and I wish you good luck implementing it. However, it is not (very) simple to implement. Some reasons: GPS is not at all accurate; smartphones usually have a positioning error of +- 10 meters (30 feet). Unless your boats are actually some transatlantic beasts, this error is unacceptable; GPS receivers with (very) high ...

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Yes, robotic arms or other devices could write for you. They can even be more prolific than Shakespeare. But probably the poetry they write is not your desideratum. If you plant numerous electrodes in your head to monitor the spikes your neurons generate, the robotic arm may have a chance to share your thoughts thereby writing for you as you wish. However,...

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You will need to determine if the Zumo is Arduino shield pinout compatible. It appears the Zumo has a compatible microcontroller. This likely means that you would be able to use the Arduino IDE, compiler and libraries to program your robot. If the Zumo is not pin compatible, you may want to investigate the ESP8266 range of SoCs. They're a microcontroller ...

1

Unfortunately I don't have enough rep to comment or I would do that instead of a full blown answer. I think Rf modules would be the way to go in this situation, I have played around with this trans/recv pair before and had pretty good results, however I don't think the range would quite be enough for your setup. With regards to you mentioning 16 robots ...

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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 ...

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I have experience installing ROS on a Raspi using Ubuntu Mate as an operating system. It is essentially a regular ubuntu operating system, but on an arm device. It can install ROS through pre-built binaries. It requires no more configuring than a regular Ubuntu laptop. I know that there is one version of the Pi that is not officially supported (I think it is ...

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In contrast to what has been said in the other (rather outdated) answers, I've successfully tried running ROS on either Raspbian or Ubuntu with a Raspberry Pi 2 Model B. After some back and forth, I'll stick with Ubuntu: While I didn't managed to access the Raspberry camera module with Ubuntu, I see major advantages in its superior package management and ...

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What parameters should I watch when selecting an antenna? The biggest one is going to be the application, does it need to operate outside? in pouring rain? does it need to be omnidirectional? Is it ok to use indoor stick antenna and seal the mounting point with hot glue? Generally this will work just fine depending on how harsh the environment, outside ...

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Depends whether you're talking Point to point or just in a wifi field. According to the datasheet the transmit power is +16dBm or 40 mW and a maximum sensitivity of -93dBm. According to my favorite link budget calculator with 2 of these modules both with 22dBi gain antennas on them you will get around 6 miles (RF line of sight) out of them with a respectable ...

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To my knowledge, the WifiBee doesn't support network scanning. You must specify the SSID of the Wifi network that it should connect to, the IP address it expects to be assigned, and the gateway address as part of its initial configuration.

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You're attempting to move a robot along a predefined path without the aid of sensors, so really we just need to convert the list of points into a list of pre-scripted actions. Convert input points to $({\Delta}x, {\Delta}y)$ pairs Convert $({\Delta}x, {\Delta}y)$ pairs to $(\Delta\theta, d)$ pairs Convert $(\Delta\theta, d)$ pairs to \$(V_{left}, V_{right}, {...

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There are two ways you can approach this problem, open-loop and closed-loop. Open-loop approach should be easier although it will be highly inaccurate. The closed-loop is more complex but it should improve the accuracy. The decision depends on your application and how much time you can spend. The robot has to follow a requested path drawn by the user. To do ...

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for the hardware You don't say what type of motor you use. If it's a DC-brushed type, putting more or less voltage will not necessary linearly alter the speed, in fact if you increase the voltage the relative amount the load on the motor increase the speed won't change. To do a good control you need a feed-back of the motor or wheel speed, or an angle ...

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Any WiFi system should be able to report the signal strength (in dBm), but the question will be how quickly you need it to report values and how accurate a measurement you are looking for. The main problem with what you're suggesting is that the relationship between signal strength and distance is not necessarily linear. Antennas produce an interference ...

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