I just finished my first month of having the shop open and it feels pretty good. After I was able to open the shop up, I could finally get down to other pressing things like designing new boards and looking for interesting products to stock. There are also tons of other things that needed to be done like writing documentation and putting together tutorials on how to actually use what I’m selling. I think that’s one of the hardest parts about having a shop and one of the areas that can really make or break things.
I really enjoy scouting for new products. It gives me an excuse to buy a bunch of parts and try them out. There are a lot of duds, but the more things you try, the more ideas you get and recently, I seem to be bursting with ideas…well that or I’m going to have an aneurysm soon. I try to keep the theme of wireless sensor networks in mind when I’m scouting for products and you can see that a lot of the new products are somehow related to this, however there are a couple that get through because they’re just too cool to pass up. Here’s the rundown on what’s new:
GMM Speaker Actuator
WTF’s a GMM? That was the first thing I asked myself but decided to check it out. The GMM speaker actuator is extremely cool and turns any flat surface into a speaker.
GMM stands for Giant Magnetoresistive Material and it works based on the principle that some materials change shape when exposed to a magnetic field. For this device, a GMM is placed inside a coil and when current flows through the coil, the induced magnetic field forces the GMM to elongate. So when an amplified audio signal is passed to the device, the actuator head will vibrate according to the signal and turn anything its in contact with into a speaker. I took some videos of it in action, one with instrumental music and one with vocals:
I have a slight obsession with LEDs and created a toplevel category just for them . I also overhauled the category and removed the regular LEDs for the moment and added a bunch of power LEDs. Normal LEDs that are used as indicators or blinkie lights usually run at around 10 to 50 mW. The LEDs that I'm stocking are all running in the range of 1 to 3W and require heat sinks.
There’s a general trend towards solid state lighting and LEDs are getting more and more powerful. LEDs have a lot of benefits over standard AC lighting. They’re much more efficient than incandescent bulbs and even more efficient than fluorescent lighting. You can also dim and control them much more easily and without the headaches associated with dealing with high voltage AC like isolation and zero-cross detection. Normally, all you need is a power transistor and a microcontroller pin that outputs a PWM signal. Many wireless sensor network developers/enthusiasts are targeting home automation and lighting which I’d like to say is one of the reasons I decided to carry them. But in reality, I love LEDs and 1W and 3W power LEDs are just too cool.
All of the LEDs come mounted on a thermal heat sink which consists of a PCB with a thermally conductive substrate and coated with aluminum. The 3W LEDs will require extra heat sinking because those guys get really hot. The 1W and 3W RGB LEDs are especially interesting because they can be used as mood lighting for art projects, interior design, or retail displays.
1 Watt LED Module
White, Warm White,
Blue, Green, Red, Yellow
3 Watt LED Module
White, Natural White, Warm White
Blue, Green, Red, Amber
| 1W RGB LED Module|| 3W RGB LED Module|
24 GHz Radar Speed Sensor
Who could pass up a 24 GHz microwave radar speed sensor? This is a short range radar speed sensor that operates at 24 GHz and can be used for motion or speed detection. They’re often used in high end automobiles for collision and obstacle detection, but they can also be used as motion sensors or to measure the speed of oncoming traffic. I actually wrote a tutorial about how to use them and you can see more about this sensor in the tutorial.
Peripheral and Radio Boards
ADXL345 Sensor Board
I released a new sensor board this month which is based on the ADXL345 3-axis accelerometer. There is a lot of interest in using accelerometers with wireless communications for things like fall detection for the elderly, seismic detection, or vibration sensing. The ADXL345 has many interesting features and one of the best ones is that the data is already digitized and available via the I2C or SPI interface. I support both interfaces for the board in case there is any preference.
There are also configuration registers for different power modes on the accelerometer, tap and double tap detection, activity and inactivity thresholds, and interrupts that are mappable to either of two interrupt pins. The board also has the standard FreakLabs interface connector so it will be compatible with any of the MCU boards that are either currently available or will be available in the future.
I think my design pipeline is really exciting and I should be adding a bunch of new boards really soon. Here is a preview of what’s coming up:
900 MHz 802.15.4 Radio with 500 mW Amp
One of my favorite designs is a new radio board which should be released next week. It combines Atmel’s AT86RF212 900 MHz 802.15.4 radio with the TI CC1190 500 mW RF front end. I’ve been eyeing the CC1190 for a while and it just recently became available. It combines a 500 mW Tx amplifier and an 11 dB Rx low noise amplifier. If you’re not familiar with RF specs, I can just say that this radio will get some serious range.
It actually took me quite a bit of effort to get to the final product. Here’s the initial three prototypes that led to the final board.
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And here's a shot with a high gain omni-directional antenna. Perfect for monitoring your volcano sensor network :)
900 MHz Chibi board
This board will be extending the Chibi series of low cost WSN prototyping boards to support 900 MHz. I’ve recently fallen in love with 900 MHz radios which suffer much less path loss than 2.4 GHz and hence get better range. These boards are basically identical to the 2.4 GHz Chibi boards, but use the Atmel AT86RF212 radio. This radio can pump out 10 mW on the transmit side, supports 780, 868, and 915 MHz for China, Europe, and the US unlicensed bands, has a special mode for 1 Mbps throughput, and if more range is needed, can also have the modulation changed for a 5-10x boost in receiver sensitivity (using BPSK).
This one will be available after the 500 mW radio board is released. It’s just waiting on documentation.
Humidity and Temperature Sensor Board
This board combines a Honeywell instrumentation grade humidity sensor (HIH-5030) with a Microchip precision temperature sensor (MCP9804). The actual reason this board came into existence is that one of the Tokyo hackerspace members casually mentioned to me that he’d like a wireless humidity and temperature sensor to monitor his wine/cheese cellar. Yes, he has a wine/cheese cellar. So I figured, why not put that together, and boost the specs a little bit.
The Honeywell device has a covered IC humidity sensor which makes it robust in harsh environments and comes pre-calibrated. The Microchip temperature sensor is one of the most precise IC temperature sensors I could find and it has an accuracy of +/-0.25 deg C and a digital I2C interface. Overall, it looks like quite a nice combination, perfect for cheese cellars…
This one is waiting on documentation and test software. It should be available shortly.
Atmel ATXMega MCU Boards
These just got sent off to the fab last week and I can’t wait to get them back. These boards actually came out of a conversation I had via email about making boards that can be used by TinyOS. Since my current boards use an integrated USB, there is no way to use them for TinyOS without significant low level porting work to the underlying nether regions of TinyOS. Hence, I started looking for a good MCU that I could throw an FTDI USB bridge on which would make a port much easier. A standard ATMega would be too boring since those are already well covered in TinyOS, and if I veered too far off, like say an ARM Cortex-M0, then the porting effort would be really painful. So I started looking into the Atmel ATXMega’s…and then got really excited...
Atmel’s ATXMega MCUs have some extremely interesting features that are perfect for wireless sensor networks. I’ll be doing a full post on why I think the ATXMegas are the "shiz-nitz", but here are a few of the features I really like.
- Integrated 2 MHz clock source and a PLL:
- No external crystal needed and the PLL can multiply the clock source all the way up to 32 MHz via register access. Forget about the single clock frequency MCU. This one lets you run at whatever frequency you need to run at to get the job done. Being able to dynamically scale the clock frequency based on computational load has many possibilities in the area of power conservation.
- Integrated Real Time Clock.
- People often overlook the fact that if you have a distributed sensor network, you need to synchronize the data for analysis. This means you need an accurate clock source for timestamping the data.
- Event system.
- As strange as this sounds, you can actually take samples from the ADC, timestamp them, and move them to memory…all while the MCU is asleep.
- External memory bus.
- This one deserves a full post and I’ll be writing more about this later. But WSNs are generally diverging into the traditional node which is extremely resource constrained and mainly designed to collect & transmit data, and more full-featured nodes that support a rich set of features and application level protocols. The most obvious example is the creeping resource requirements of both Zigbee and 6LoWPAN (mostly due to application level constraints and the need to interface with web technologies). Hence, one of the MCU boards will support the ATXMega-A1 family which has an external memory bus. My original prototype had 512 kB of SRAM loaded on the MCU (heh heh), however AVR-GCC doesn’t support 24-bit pointers so the max RAM it can address is 48 kB (16 kB is used for internal RAM + periphs). So the final boards will probably be loaded with 32 kB SRAM chips.
The PCBs should be arriving in about a week and a half and from there, will undergo testing and documentation. Hopefully they can be released early to mid June.
Well, I guess that's about it for the updates. If you made it this far, thanks!