An Arduino pulse sensor project from Bajdi:
I found a little heart rate sensor @ ICstation. It is a clone of the open hardware pulse sensor. The sensor is well documented, and it comes with Arduino and Processing example code.
To try it out I connected the sensor to an ATmega328 running at 3.3V and loaded the example Arduino code. I could now see my heart beat on the Arduino serial monitor
I then connected a 2.2″ TFT display to the Arduino and tried to figure out how to display the sensor output on it. Sounds simple but unfortunately it isn’t. Updating the full screen (320×240 pixels) is really slow. So I needed some smarter code to update only the pixels that needed to change. I happened to stumble on Matthew McMillans blog, he wrote some smart code to use a similar display as a speedometer. So I borrowed some of his code and mixed it with the example code of the pulse sensor. You can see the result in the above video.
Arduino heart rate sensor - [Link]
Jason over at Rip It Apart did a teardown of a Kentli PH5 1.5 V Li-Ion AA battery:
The PCB that holds the 1.5 volt regulator is inside the end cap, with the rest made up of the Li-ion cell itself. Curiously enough, the cell inside is labeled “PE13430 14F16 2.66wh” which is interesting in more than one way. First of all, the rated energy content of the cell is less than what’s on the outside label (2.66 watt-hours versus 2.8), and the cell inside is actually a Li-ion polymer (sometimes called a “Li-Po” cell) type; I was expecting a standard cylindrical cell inside. Unfortunately, my Google-fu was unable to pull up any data on the cell. I might attempt to do a chemistry identification cycle on the cell and see if TI’s battery database can bring something up.
Teardown of Kentli PH5 1.5 V Li-Ion AA battery - [Link]
by Martin Rowe @ edn.com:
With today’s circuit components in ever–shrinking packages, finding an overheating component or a component damaged from heat during assembly can be a challenge. To help isolate those components, Fluke has introduced the TiX series of high-definition thermal imaging cameras.
Consisting of the models, the TiX series cameras have resolutions of 1024×768 and 640×480 pixels that display across the imager’s 5.6-in. display. That’s 3.1 million pixels and 1.2 million pixels, respectively, when using SuperResolution mode. The TiX imagers have a temperature range of -40°C to 2000°C (-40°F to 3632°F).
See the details with an HD thermal imager - [Link]
by Stephen Evanczuk @ digikey.com:
For rapidly growing markets such as wearables or the Internet of Things (IoT), energy harvesting can significantly enhance battery life—or even enable battery-free designs. At the same time, however, engineers designing wearables and IoT devices face significant constraints in total design size and footprint. To meet growing demands for miniaturized systems, designers can turn to an array of highly integrated energy-harvesting ICs and wireless MCUs from silicon vendors including Atmel, CSR, Freescale Semiconductor, Linear Technology, Maxim Integrated, NXP Semiconductor, Silicon Laboratories, STMicroelectronics, and Texas Instruments, among others.
Energy harvesting offers tremendous benefits for applications able to take advantage of ambient-energy sources. Designers have employed energy-harvesting techniques to power applications ranging from motor and engine monitors to railway trackside electronics. Typically, these applications are based on wireless-sensor designs built to transmit sampled data about the environment or events of interest to a controller, aggregator, or other host (Figure 1).
Specialized ICs Squeeze Large Capabilities into Tiny Energy-Harvesting Solutions - [Link]
Diodes Incorporated introduced a pair of compact 40 V, 1 A-rated gate drivers specifically designed to control the high-current power MOSFETs used in onboard and embedded power supplies and motor drive circuits. Enabling the MOSFETs to be more rapidly and fully switched on and off, the ZXGD3009E6 (SOT26 package) and ZXGD3009DY (SOT363 package) help minimize switching losses, improve power density and increase overall conversion efficiency.
Acting as a high-gain buffer stage for low-power control ICs, the devices can provide a typical drive current of 500 mA from an input current of only 10 mA, ensuring the desirable fast charging and discharging of the power MOSFET’s capacitive load. The drivers’ switching capability is ultra-fast, with a propagation delay time of less than 5 ns, and rise and fall times of less than 20 ns.
MOSFET Gate Drivers from Diodes Incorporated Boosts Conversion Efficiency - [Link]
by Amy Norcross @ edn.com:
A new way of switching the magnetic properties of a material using just a small applied voltage could signal the beginning of a new family of materials with a variety of switchable properties, according to a team of MIT-based researchers. The technique could let a small electrical signal change materials’ electrical, thermal, and optical characteristics.
Researchers use voltage to control magnetic memory - [Link]
by Ludic Science @ youtube.com:
A very simple SSTC based on the slayer exciter circuit (first developed by GBluer) is shown and construction instructions are given.
Miniature Solid State Tesla Coil (Slayer Exciter) - [Link]
If anybody is interesed, I have posed a follow up to this original post with a simple PWM LED driver, adding an ATtiny85 mCU. The post includes schematic, board layout and code for the ATtiny85. I hav tested the circuit up to 22 volts without a current limiting resistor. The FET only needs a small heat sink. Efficiency can be further improved by replacing the LM358 with an RC/LM741. The LM741 has a much sharper rise and fall time than the LM358 when run at 2KHz, resulting in the FET spending less time as a resistor. (during the slow ramp/fall the FET acts as a resistor, generating heat)
PWM Based LED Driver - [Link]
Moreover, new UMTS/HSPA module Quectel UG95 is pin-compatible with GSM/GPRS module M95 thus offering extraordinarily simple way to migrate to 3G without a PCB redesign.
To have a possibility to choose a component on a given PCB place according to our wish is certainly advantageous. For example in audio equipment to use a simple operating amplifier (for less demanding applications) or in other case to use a pin-compatible high-end operating amplifier for more demanding applications (on the same PCB position). This compatibility is common in some fields, in other ones not that much …
In a segment of GSM/GPRS/UMTS modules is this compatibility a sort of an exception, so arrival of the new Quectel UG95 module on the market can be an interesting solution how to use the same design for smaller GSM/GPRS/EDGE connection (with the M95 module) and also for a substantially faster UMTS/HSPA connection with the UG95 module.
Do you use 2G module M95 and you wish for a higher transfer speed?
UG95 offer extraordinary possibility to design your device able to work with M95 or also with UG95 module. UG95 features more pins than M95 but their position is compatible, so at a PCB design it´s possible to place all pins on a PCB and their real use will depend on whether you´ll use M95 or UG95.In result it´s possible to assemble the same PCB with M95 or UG95 module according to given application requirements.
UG95 is based on a new Intel XMM6255 chipset. In general, UMTS/HSPA transfer offers not only a higher transfer speed of pictures and data but mainly higher reliability of connection even in hazard conditions. That can be very important for critical applications like telemetry, process control, security and similar. Because from a new module we usually expect enhanced functionality, even in this field the UG95 has what to offer, for example:
- rich set of internet protocols – TCP/UDP/PPP/MMS*/SMTP*/FTP*/SSL* (*-in development)
- standard industrial interfaces – USB 2.0/UART/I2C/PCM
- high sensitivity and top-class audio algorithms, digital audio output (PCM)
New module is available in a form of the module itself – UG95EA-02-NCH-STD (suitable for a mass usage into a target appliance) and also in a form of a known „adapter board“ UG95-TE-A mainly intended for development using the UC20EVBKIT development kit.
UMTS module UG95 = reliable transfer even in hazard conditions - [Link]