There are several ways to add wireless connectivity to your sensors, relays, motors, or other devices. Bluetooth, Zigbee and Wi-Fi can all do a good job for short ranges, and the Weigthless standard will eventually provide ranges up to 10km with ultra low power on free spectrum, but it is not available right now, and a good way to achieve longer ranges is to use cellular networks. SparqEE has designed a development kit called CELLv1.0 to add GSM and 3G connectivity to the Internet of things, including (optional) shields for Arduino and Raspberry Pi boards. Here are some technical specifications for the kit: Cellular Networks – WCDMA/HSDPA 2100/1900/900MHz, GSM/GPRS/EDGE 850/900/1800/1900MHz, 384Kbps, DL3.6Mbps HSDPA via ZTE modem Protocols – Data (TCP/UDP), SMS ready Serial interface – Serial (UART, From Cellular Board is 1.8V, From Jumper board is any voltage (ex. 3.3V, 5V)) USB – (power, USART, and modem) Input Voltage – […]
HDMI to VGA Adapters Now Cost About $10
I remember when the Raspberry Pi first got out, many people wanted to connected it to a VGA display, and at the time, a cheap HDMI to VGA adapter would have cost $30, about the same price of the low-cost ARM11 board. Since then things have changed since it’s possible to find HDMI to VGA adapters for less than $10, and even less than $7 on Aliexpress. The one linked and pictured above has an HDMI male connector and a VGA female connector, and the following features listed in buyincoins: Support 1080p and 720p. Built-in chipset. No external power required, power supply from HDMI signal. Don’t support audio output. Can use for connecting devices with VGA port to HDTV. HDMI – standard type A port male. VGA – VGA video port, female. The title seems to imply it’s an HDMI to VGA adapter, but the description tells you it’s for […]
WigWag Simplifies Home Automation, Provides Raspberry Pi and Arduino Shields
WigWag is an home automation kit aiming at simplifying home automation, yet allowing developers to roll their own system via Arduino and Raspberry Pi Shields. Wigwag is currently composed of three devices: WigWag Sensor Block – Universal sensor device with 8 environmental sensors (light, detect motion, sound, temperature, humidity, movement…), 4 control features (relay, IR blaster…), and 2 expansion ports. It can be powered by 4x AA batteries (possibly for up to 1 year), or a USB power adapter. This device runs Contiki OS on Freescale MC1322 MCU (with built-in 6LoWPAN radio). WigWag Relay – Connects WigWag and third party devices to their cloud service, allowing interaction with Internet services, such as email, Dropbox and Twitter. It acts a bit like a central server managing all your WigWag Sensor Blocks or other connected devices such as Phillips Hue light bulbs or Belkin WeMo outlets in your house. IP networks (Wi-Fi & Ethernet) […]
DIY Stripboard/Veroboard Enclosure for Raspberry Pi (Part 2)
Following up my previous post entitled “DIY Modular Stripboard / Perfboard Casing for Raspberry Pi (Part 1)” where I explained how I created an modular enclosure made of perfboard, or the overall concept, I’ve now designed two “smart” sides for the enclosure: a 16-LED stripboard side, and a 5V relay stripboard side. Today, I’ll detail how I’ve done this, with details about electronics, soldering, assembly, the Linux distribution (built with Yocto), as well C programs, HTML page, and (CGI) shell scripts used to light up the 16 LEDs, and control a standard 220V lamp with a relay via my phone’s web browser. 16-LED Stripboard Top Schematics, Soldering, and Testing I had decided to design the top board of the enclosure with several LEDs, 3 LEDs on both side, and a Raspberry fruit (6 red LED) and 2 leaves (4 green LED) in the middle. Before getting started, I did some […]
12MB Minimal Image for Raspberry Pi using the Yocto Project
Last year, I wrote instructions and provided a download link about a minimal image for Raspberry Pi based on Raspbian. The compressed image is 84MB, and the good thing about it is that you can just use apt-get to install packages. The problem is that it’s not actually that small as once it is uncompressed the rootfs is still a massive 414 MB. So today, I’ll explain how to create a smaller (and custom) image using the Yocto Project, a platform that let you build an embedded Linux distribution matching exactly your project’s requirements. Other advantages are that the build is configurable with config files, so it’s easily reproducible with a few command lines, and it might turn out to be useful to learn more about the Yocto Project as many boards and SoC are now making use of the framework, including Freescale i.MX6 (Wandboard, Olinuxino-imx233, Sabrelite, etc…), the Beagleboard, […]
DIY Modular Stripboard / Perfboard Casing for Raspberry Pi (Part 1)
I plan to play around with Bluetooth 4.0 LE in Linux using the Raspberry Pi as an hardware platform together with a small LCD display and possibly a relay board. Instead of having boards spread around, I thought it might be a good idea if I could design a case for my setup. I wanted to be able to connect small external boards and things like LEDs, it had to be easily assembled and disassembled, modular so that I could add or remove circuits easily, and about as cheap as existing “dumb” cases. So I though why not use stripboards (perfboards) for that? I searched the web to find out if other people had the same idea, and could only find one other person, but he does not appear to have completed assembly, nor actually used the stripboards to add hardware features. I decided to give it a try anyway, […]
Stealth Nighthawk F-117A is a Raspberry Pi-in-a-Stick Preloaded with XBMC
Stealth Nighthawk F-117A was a “single-seat, twin-engine stealth ground-attack aircraft formerly operated by the United States Air Force (USAF)”, but it’s now an HDMI dongle based on the same processor as the Raspberry Pi, namely Broadcom BCM2825, software compatible with the Raspberry Pi, and preloaded with an XBMC OS, which turns out to the Raspbmc. The main hardware differences with Raspberry Pi are that you lose Ethernet, composite output, and all headers used for hardware hacking, but you gain Wi-Fi, a casing, and an even smaller form factor. Here are the specifications of the device: SOC – Broadcom BCM2835 @ 700mhz with Video Core IV GPU/VPU System Memory – 512MB Storage – micro SD card slot (up to 32GB) USB – 1x USB 2.0 host port + micro USB port for power Video Output – HDMI (up to 1080p) Connectivity – Wi-Fi 802.11n Power – 5V/1A via microUSB port Dimensions – […]
$25 Texas Instruments SensorTag is a Bluetooth LE Devkit with 6 Sensors
Yesterday, I wrote about Wimoto Motes, tiny Bluetooth LE devices with several sensors that can be controlled and monitored via an iOS app, and soon by an Android app, as well as Linux devices. Each mote costs $39 plus shipping, and one commenter mentioned the price may be a bit too high. A Google search for “bluetooth sensor” immediately brings TI SensorTag, which looks somewhat similar, except it is a Bluetooth LE development kit, includes 6 sensors (but no light sensor), and only costs $25 including shipping. SensorTag Specifications: Bluetooth 4.0 low energy (CC2541) SoC 6 sensors connected via I2C: IR Temperature sensor (TI TMP006) Humidity sensor (Sensirion SHT21) Pressure sensor (Epcos T5400) Accelerometer (Kionix KXTJ9) Gyroscope (InvenSense IMU-3000) Magnetometer (Freescale MAG3110) Power – Single cell coin cell battery (CR2032), quiescent current consumption of 8uA, allowing years of battery life. FCC, IC and ETSI certified solution Dimension – 71.2x36x15.5 mm, […]