Monthly Archives: February 2015

Rapiro the Customizable Robot with Raspberry Pi

If you have a kid aged 15 or above with a Raspberry Pi and he is clueless about his next project, Rapiro, the customizable robot may be very suitable for him. Designed for the tiny credit card sized single board computer, the Raspberry Pi or RBPi, Rapiro is a humanoid robot kit. It is an affordable kit and is very easy to assemble, needing only two screwdrivers. With an Arduino compatible controller board, the kit comes with 12 servomotors and limitless possibilities.

Even if you are not a programmer, Rapiro is easy to assemble and set up. The assembly instructions are simple and given in a step-by-step method, so anyone can follow them. Rapiro’s controller board is pre-programmed, so that Rapiro will come alive as soon as you have finished assembling it. However, if you are a programmer, you could make Rapiro sweep your desk or have him dance to a tune. For this, you will need to use the Arduino IDE to reprogram Rapiro.

Rapiro is highly customizable. Limited only by your imagination and the sensors you have at hand, simply install the RBPi board and go on expanding the capabilities of Rapiro. For example, you can add image recognition, Bluetooth, Wi-Fi and anything else you can think of to make Rapiro livelier.

Rapiro has 12 servomotors to make it move. There is one servomotor in its neck, one in its waist, two each in its feet and three each in its two arms. There are six servos in its neck, waist and feet have a torque of 2.5kgf-cm each. The servos in its two arms have a torque of 1.5kgf-cm each. The operating speed for all the servos is 0.12sec/60° and the maximum angle they can move through is 180°.

You can program it’s eyes to give its face a full and colorful expression. Its eyes are made of bright LEDs, which can be programmed for different colors as they are of the RGB type. Plastic parts of Rapiro suit both models of RBPi – A and B. With small modifications, Rapiro can accommodate RBPi model B+ as well.

Rapiro’s controller board is very similar to an Arduino board and you can program it using the Arduino IDE. Anyone familiar with C++ development environment can use the Arduino IDE to program the 8-bit AVR based micro-controller on board Rapiro. However, that does not mean only those with programming skills can work with Rapiro – beginners can also learn how to program.

Once you have installed RBPi inside Rapiro, you can make it do more functions. With RBPi, you can use your favorite programming language on Linux to program Rapiro. For example, you could program Rapiro to watch over your home while you are away and to keep in touch by sending you text messages over Wi-Fi. You could have Rapiro acting as a security robot for your house if you give it vision by installing a camera module.

Rapiro requires five AA Ni-MH batteries to function. You can replace this with an AC adapter also. For transferring data, you will also require a USB cable to connect Rapiro to your PC.

How Do RCDs Protect?

If you touch something electrically live, such as a bare wire, chances are that you will receive an electrical shock that may even be fatal. An RCD or a Residual Current Device protects you from this danger, offering a level of personal protection not provided by circuit breakers and fuses. The RCD, being a sensitive safety device, automatically switches off electricity when it senses an earth fault.

Earth faults are associated with the risks of electrocution and fire. Such faults happen, for example, when you accidentally touch a faulty appliance or an exposed live wire, causing electric current to flow to earth. Outdoors, such faults may be the result of a lawn mower cutting through the supply cable.

When an RCD is protecting a circuit, it constantly monitors the electric current flowing through the different paths. The RCD switches off the circuit very quickly as soon as it detects an unusual electrical activity such as current flowing through the body of a person who has accidentally touched a live part. This reduces the risk of serious injury or death.

Using RCDs is an effective way of protecting oneself from electric shock in potentially dangerous environments such as gardens and bathrooms. To be as safe as possible, the RCD to be used must be chosen carefully from among fixed, socket-outlet and portable types.

Fixed RCDs are usually installed in commercial and industrial places at the consumer unit or fuse box. Typically, they provide protection to individual or groups of circuits. As all wiring, sockets and connected appliances on a circuit remain protected by the fixed RCD, it offers the highest level of protection.

Special socket-outlets can have RCDs built into them and you can use them in place of standard socket-outlets. This type of RCD will protect only the person who is in contact with the equipment plugged into the special socket-outlet, including the equipment’s lead.

You can plug portable RCDs into any standard socket-outlet. Just like the socket-outlet RCDs, It will protect any person who is using a device (including its lead) plugged into the portable RCD. This is a very useful device when neither the fixed nor the socket outlet RCDs are available.

Reliability of an RCD increases when tested regularly. Apart from reducing the risk of electric shock to you and your family, fixed RCDs will also defend your home against the risk of fire caused by an appliance or faulty wiring.

Although protection by using an RCD does reduce the risk of injury or death from electric shock, it does not mean that you should not be careful. Get your home wiring checked every ten years to ensure the safety of your home and your family. A registered electrician should immediately attend to any fault in the wiring or an appliance.

Be aware that if the RCD does not shut off the electricity supply even after you have held the test button for a long time, the RCD is most likely not functioning. Have it replaced or take advice from a registered electrician.

How Are Sensor Hubs Helping Android?

The duties of a sensor hub are rather specific. They usually take the form of an additional micro-controller unit, a coprocessor or a DSP that integrates data from various sensors and processes them for the benefit of the main central processor. Not only does this technology off-load several jobs from the main central processing unit of a product, it saves battery consumption and provides an upward jump in its performance.

Most smartphone, tablet and wearable manufacturers including application developers are targeting mobile devices in the near future that will always be aware of their surroundings and activities. This will lead to providing meaningful results and content to the user. Inputs for the Always-on Context Awareness will be delivered by numerous sensors located within a mobile device, a separate micro-controller or a sensor hub fusing and computing their data.

PNI Sensor Corp. is making such a tiny 2×2 millimeter package as a sensor hub. It is by far the smallest, smartest and the lowest power-consuming implementation of a sensor hub. Consuming barely 200µA, this sensor hub implements the complete sensors function for the latest KitKat Version 4.4, as mandated by Google. Furthermore, PNI has incorporated all the KitKat functions without implementing an extra processor. This will greatly extend the battery lives of Android devices, even if they are using all their functions 24×7.

Android device manufacturers have two other choices. They could write their own fusion software and have them run on processors such as from Atmel or ARM. They could even license such software from others. On the other hand, OEMs could use smart sensors that have some functions implemented on-chip, while running the rest on the application processor. However, both the above methods are power-hungry and likely to consume up to ten times the power compared to the solution offered by PNI.

SENtral-K hub (the K standing for Google’s KitKat), from PNI can handle all the hardware connections from the MEMS sensors, while managing the virtual sensor functions in the software including the dedicated state-machine logic. The hub uses a tiny processor, the Synopsys ARC, along with specialized state-machines. Together, they achieve 140-thousand FLOPS or floating-point operations every second, while consuming less than 200µA at 1.8V. Being sensor agnostic, SENtral-K allows OEMs to select the lowest power consuming sensors from all different suppliers. This includes sensors such as for ambient light, pressure, proximity, magnetometer, gyroscope, accelerometers and many more.

SENtral-K combines all the outputs from the raw sensors and provides KitKat with the necessary functions it demands. These include functions such as step-detect, step-count, significant motion, linear acceleration including all the functions based on location and others that Google wants to incorporate at all times for their apps such as Google Now. The tiny chip comes fully pre-programmed to handle all functions demanded by Google’s KitKat 4.4.

For example, SENtral-K is capable of handling Android 4.4 KitKat functions such as those with nine degrees of freedom or DOF – 3-axis magnetometer, 3-axis gyro and 3-axis accelerometer. It can also handle six DOF – accelerometer and gyro or accelerometer and magnetometer. Other functions it can handle include Timestamp, Data Batching, Uncalibrated Sensor, Calibrated sensor, Significant Motion, Step Detect/Count, Linear Acceleration and Gravity.

Expansion Board for Wi-Fi Connectivity for Raspberry Pi

The tiny credit card sized single board computer, the mighty Raspberry Pi or RBPi is mostly self-contained. However, the small footprint of the SBC has not allowed many important functions to be integrated within it. For example, the RBPi lacks an in-built Wi-Fi. This has led to several developments of Wi-Fi add-on kits, with the xPico Wi-Fi Plate from Lantronix leading the pack.

This pluggable, simple and easy-to-use expansion board from Lantronix provides a feature-rich and robust Wi-Fi solution that few can match. It enables the RBPi to attain several mobile-ready capabilities very easily and quickly. Not only does the xPico completely offload all Wi-Fi connectivity from the RBPi, it also provides many advanced capabilities such as Soft Access Point or Soft AP and Client Mode, along with QuickConnect and Wi-Fi connection management.

Combining xPico with RBPi allows developers to concentrate on the main application for RBPi. This is possible because xPico takes care of all the concerns about wireless connectivity management and wireless stacks while providing hassle-free Wi-Fi connectivity. Users get a robust and true 802.11 b/g/n solution, which provides a painlessly enabled Wi-Fi access either as a client or as a Soft AP. In fact, xPico offers a whole gamut of features along with industrial-ready quality and ease-of-use. Therefore, whether you are a hobbyist, a student or an engineer, you can readily enable your RBPi platform to achieve mobility by offloading the TCP/IP stacks and networking applications such as a web-server to the xPico Wi-Fi.

The xPico expansion board is an embedded wireless device server and has several useful functions. For example, it can provide a universal wireless technology to your tablets and smartphones. Your product designs can be faster now with the simplification of Wi-Fi implementation and integration. It provides unmatched flexibility as the footprint is compact and power consumption is very low. The proven feature-set includes simultaneous Soft AP and client mode, configuration by customization and zero host load. The user improves his competitive position by saving on cost and time-to-market. In short, xPico is designed with the necessary functionality to differentiate your Wi-Fi enabled products by providing flexible, mobile-ready Wi-Fi solutions for IOT and M2M applications.

If you are looking for a robust, full-fledged networking solution, the Lantronix xPico Wi-Fi module provides an extremely compact and low-power alternative. It will provide wireless LAN connectivity on virtually any platform that has SPI, USB or serial interface, such as on an RBPi.

Being one of the smallest embedded device servers in the market at present, you can utilize the xPico Wi-Fi module in designs that require chip solutions, as it befits the advantages to cost and time-to-market. The connected micro-controller need not have any drivers as xPico provides the zero-host-load feature. Therefore, implementation becomes very simple, since not a single line of code has to be written. That translates to a considerably reduced development cost and complexity. Additionally, xPico Wi-Fi meets all EMC and safety compliances such as EN, UL and FCC Class B.

Another advantage with the xPico Wi-Fi module is that it is compatible to a huge range of embedded microprocessors and controllers.