Monday, September 10, 2012

Creating Bluetooth 4.0 accessory - How to start?

We predicted that the Bluetooth 4.0 will be the technology that will revolutionize the gadget and accessory market for mobile devices. The trigger for the avalanche of wireless gadgets could be the upcoming release of iPhone 5 / iOS 6. At the same time as the next generation wireless connectivity finds its way to mobile devices, the world of gadget making has been revolutionized by the crowd-funding sites such as the kickstarter or the Indiegogo. These sites give opportunity to anyone to start manufacturing gadgets of their liking, as long as their idea appeals to large enough audience.

We roundup Bluetooth 4.0 modules from different manufacturers to see what they have to offer for a gadget maker that needs to get
  1. Get their project on a Crowd-funding site
  2. Quick proof-of-concept ready as fast as possible (no one wants to fund slideware)
  3. Final product has decent manufacturing cost (no one wants to buy expensive gadget event for iPhone)
  4. Final product has to have global certifications (FCC and CE minimum)

Sunday, September 2, 2012

Bipolar microstepping motor driver roundup

Bipolar stepper motors are easy to drive using a microcontroller, but using a separate driver chip can arguably be a simpler and a safer option. Using a dedicated chip is especially convenient when controlling multiple steppers or using micro stepping.

There are currently a huge selection of stepper motor driver chips on the market, a single vendor may carry over a dozen slightly different versions.

A list of interesting stepper motor drivers after the break.

Thursday, August 30, 2012

iPhone 5 - enabling the Internet of Things?

When iPhone 4S was introduced approximately one year ago, not that many people realized what was perhaps the most crucial feature that differentiated the iPhone from the other mobile phones. It was not the easily breaking glass design, the dual core  ARM Cortex-A9 or even the Retina display. It was the Bluetooth 4.0 that really made the iPhone 4S to standout from the competition. Even though the general public did not really see the difference between Bluetooth version 4.0 and its predecessors, the 4.0 included a totally new technology under the Bluetooth specification which allowed the creation of extremely energy efficient wireless accessories and gadgets.

You might ask how this relates to the iPhone 5? Well, let me go though some facts and let you figure it out. Prior to releasing iPhone 4S, Apple joined the Executive Board of Bluetooth SIG. Coincidence, perhaps? Joining the board of the organization that controls the development of Bluetooth gives them capability of both monitoring the adaptation rate of the technology and to certain extent, steering the development of it. Apple has since released new iPad, MacBook Air, Mac Mini and MacBook Pro; all with Bluetooth 4.0 support. Now one year after the release of the iPhone 4S there are only couple of other mobile phones that support the latest Bluetooth version.

Tuesday, August 28, 2012

Azoteq's IQS232 offers inexpensive capacitive touch

Azoteq's new IQS232 is a 2-channel capacitive touch senor with some interesting features, such as an impressive 3uA operating current and a claimed sensing distances of 25cm in air and 2.5cm through glass (although the exact setup for achieving these is not mentioned).

For ease of integration and lower cost, the IQS232 is designed so it can operate in a stand alone mode, only notifying using I/Os. Alternatively, it is capable of streaming measurements over I²C to a microcontroller. The inbuilt automated re-calibration and RF noise immunity should further facilitate successful designs.

Adding a couple a capacitive touch buttons to your new design would only run you 0.30USD and is not likely to break your power budget either. You can even get an IQS232 evaluation/breakout kit for less than ten bucks.

More: IQS232, Capacitive touch application notes

Saturday, August 25, 2012

Understanding I²C and some typical uses

Having worked with multiple I²C sensors, I thought that it might be time to summarize some of my findings. For those new to I²C, the name is short for "inter integrated circuit", sometimes also known as "two wire interface" (TWI), and is very commonly used for communicating with sensors.

I²C a simple bus and allows ICs to communicate with each other in a star topology. Star topology in I²C  means one master, typically a microcontroller communicating to one or more slaves (sensors). Today it is one of the most common, if not the most common, digital interface used for to ICs to communicate.

The basics as well as the stranger features and typical terminology of I²C is covered after the break.

Monday, August 20, 2012

MEMS microphones

Traditionally a microphone is considered to be a relatively large electromechanic component that involves coils and bias currents. In the recent years the MEMS techniques have revolutionized also this area of sensors. The constant shrinking and lower power consumption of sensors makes us curious of the possible use cases those open.

One example of a small and energy efficient microphone is the Analog Devices ADMP404. Its dimensions are 3.35 mm × 2.50 mm × 0.88mm, which is rather small even for a MEMS microphone. The budgetary price listed by the manufacturer is $1.20@1kpcs, which should not be a deal breaker for most of the applications.

NXP TFA9887 amp cranks out 6dBs more sound from tiny speakers

Targeting portable devices where space is at a premium, the NXP claims its new TFA9887 can  deliver 2.6 watts RMS to speakers normally limited to 0.5 watts. In practice this means that tiny speakers can be 5 times louder without the sound deteriorating to garble.

According to NXP this is possible to do without damaging the speaker by having the chip monitor and modify the signal to keep it within safe limits. The protection also extends to monitoring the temperature of the speaker through monitoring the current draw of the element and limiting gain before the speaker gets damaged.

These protection features also allow designers to remove the high pass filtering which is typically used to limit the base, and thus the system can deliver an improved audio bandwidth.

A video demonstration and the full press release after the jump

Saturday, August 18, 2012

What is Bluetooth Smart?

Bluetooth Smart Logo
When the Bluetooth SIG released the Bluetooth 4.0 core specification in 2010, it came with a lot of confusion: terms like  Bluetooth 4, Bluetooth Smart, Bluetooth Smart Ready, dual mode, single mode and Bluetooth low energy where being used and mixed in the press as well as by chip vendors.

Explanations of what all of these mean, and how they work together (or don't), after the jump.

Thursday, August 16, 2012

Analog Devices' new IMU is not for the stingy hobbyist

Analog Devices has a new inertial measurement unit, the ADIS16480, featuring 10 degrees of freedom and incorporating sensor fusion using kalman filters. The 10 DOF come from a 3-axis gyro, a 3-axis accelerometer, a 3-axis magnetometer and an altimeter, all available over a SPI interface.

However what is sure to keep this out of the hands of hobbyists and away from your Arduino project is the price tag. Budgetary pricing for 1000pcs is an impressive 1545.00USD and even the "low cost" little brother (ADIS16448) is close to half a grand at 1k quantities. Ouch. 

Full press release after the jump.

Panasonic's long range PIR motion sensors are frugal with their energy

Passive infrared sensors (PIRs) are commonly used for motion detection in applications like burglar alarms,  automatic lighting fixtures and more recently in occupancy detection. 

Panasonic's "PaPIRs" line of  PIR sensors are small in size and have a detection range of 12m and a wide detection angle. However what makes them interesting is that they consume as low as 1.6uA of current from 3.3V whilst actively detecting any motion. This means that a single coin cell could theoretically power the sensor for a ridiculous 15 years. They're also extremely easy to use as the only output is a single digital line indicating detected motion. We can imagine these being used up in some wireless motion sensing applications where battery life is crucial.
Panasonic doesn't mention pricing details, but they are available from for example Digikey with prices around 20USD for single pieces of the lowest power model. 

More: Panasonic PaPIRs

New Beagle Board expansion boards released

The Beagle Board, an OMAP3 development board by Texas Instruments geared towards enthusiasts, now has 20 new extension boards. The boards which are called capes, likely a play on words referring to the expansion boards of Arduino called shields, add DVI connectivity, LCD displays, CAN support, Cameras, weather sensors etc. 

The goal is to let hobbyists and professionals quickly develop their ideas into working devices. According to the press release, the expansion boards are popular and more are on the way. “I expect there to be more than a hundred by next year.” said Jason Kridner, community advocate for who also happens to be working for Texas Instruments.

Analog Devices make things turn off when you stop moving

Need to make your device drain zero power when it is not used, but still keep it responsive to any movement, tapping or vibration? Analog Devices illustrates how their new ADXL362 3-axis accelerometer can be used as a power switch. While the main system remains switched off, only the accelerometer keeps draining the battery. With 300nA current consumption the ADXL362 is able to sample all three axis @ 6Hz and in case of movement occurring raise a GPIO. 

Micro Joystick

Interlink Electronics released a tiny, high-precision micro joystick. It delivers simultaneous 360-degree control of direction and speed at the touch of a fingertip. The kit includes the joystick component and a micro controller with proprietary measurement firmware. If you are limited on space then this is ideal for notebook computers, remote controls and games for example.  With its support for serial and PS/2 hardware interfaces it should be simple to use.  It claims to perform smooth cursor movements thanks to the dynamic response of the Force Sensing Resistor technology.  The evaluation kit cost around 175 GBP.  

Features and Benefits
  • Intuitive control
  • Durable
  • Smooth cursor movement
  • Versatile
  • Low power usage
  • Compact design
more: datasheet

Wednesday, August 15, 2012

Maxim pushes out more integrated light sensors

If you need a small sensor to get not just the ambient light, but the hue and infrared values, you might want to have a look at the MAX44006 and MAX44008 from Maxim. The chips both pack RGB, ambient light, IR and temperature sensors into a 2x2mm footprint. They're also touting very low power consumption numbers (15µA active) and are apparently very sensitive with 0.001Lux steps. However, his level of integration doesn't come cheap: the budgetary prices at 1000pcs start from 4.69USD and the small size means the only interface is I2C. Hobbyists will be happy to know that Maxim is quite liberal with their free samples, and such are available of these sensors as well.

More: MAX444006/MAX44008datasheetpricing