The Best NiMh Charger


Paul Allen build a great NiMh charger that connects to PC for controlling full aspects of charging process. He writes:

It’s been a long time since I posted an update on my battery charger project (in fact it has been a long time since I have posted anything!). I have been Very Busy with projects for my work and when I am not working for work, I am working on battery chargers. When I am not working on battery chargers I am trying to be a good husband and father as well as find time to do things like mow the lawn or fix the handle my son broke off the faucet.

“The Best NiMh Charger” Some may say that is quite the claim, but wait until you see all it can do (mostly thanks to the software Mark my programming friend wrote for it).

The Best NiMh Charger – [Link]

Designing a PIC24 development board


Brian Dorey has designed and built a PIC24 development board, that is available at GitHub:

One problem we found was trying to prototype code using this microcontroller as unlike Arduino and any ARM microcontrollers there isn’t a small easy to use prototyping board available for the PIC24 chip. Microchip make an Explorer 16 Development Board which is designed to work with the PIC24 microcontrollers but it is large and fairly expensive and is designed to work best with other Microchip addon cards.

With this problem in mind we decided to design and build a small prototyping board that would work with the PIC24FJ128GC006 as well as one of Microchips DSPIC33EP256MU806 dsPIC series microcontrollers. The prototyping board was designed with removable daughter boards for the microcontroller.

Designing a PIC24 development board – [Link]

Optimized Solar Tracking System

The solar energy collection is not that easy compared to the different types of power generation system because it has the lowest capacity factor. It has 5 out of 24 hours in a day that it can generate electricity from its solar collection. The only solution to this is by optimizing the 5 hours solar energy collection. This design features a solar tracker with Light-Dependent Resistor (LDR). The system is managed by a S08 MCU of Freescale. It has flash and RAM access protection that can be used in embedded development security. The system has its own protection such as illegal opcode detection with reset and illegal address detection with reset. It has also power-saving modes in which a peripheral clock-enable-register can disable the clocks of unused modules.

The design is comprised of a MC9S08PA16AVLC 8-bit MCU, S08 core, 16KB Flash that serves as the main controller of the system. It directs the movement of the servo motor with respect to the data gathered by the LDRs. It has four LDRs that will be able to locate accurately the solar radiation at its optimum point while behind these LDRs is the movable solar panel. The solar panel movement is handled by the servo motor that is also controlled by the MCU. The vertical servo is used to adjust the inclination of the panel while horizontal servo is used to adjust the horizontal position of the panel. The smart battery serves as the energy storage of the solar module that can trip off the supplies produced by the solar panel preventing it from overcharging.

The design is applicable to different types of solar module that will be able to optimize their solar energy application. It can be used in a basic robotic arm development since it features the minor movement capability of a robot or use it as a reference in the development of more sophisticated system.

Optimized Solar Tracking System – [Link]

Arduino DCF77 Master Wall Clock


by oliverb @

Time displayed on large 1″ (26mm) 7 segment displays with secondary 4×20 LCD information display. The clock can be used stand alone or provides the following pulses to drive slave clocks 1 sec alternating, 30 sec, 1 min , 1 hour, 24 hr, 15 min chime of quarter hours, hourly chime of hours.

An Arduino 328 Microprocessor is used to decode and display time & date from the DCF77 “Atomic” Clock in Mainflingen near Frankfurt Germany.
The DCF77 signal is decoded using the fantastic new DCF77 library written by Udo Klein meaning the clock stays in sync and keeps perfect time even with a massive amount of noise on the received DCF77 signal. Udo Klein’s DCF77 library also continually “Auto Tunes” the quartz crystal so in the rare event the signal can’t be decoded the clock remains accurate within 1 sec over many days.

Arduino DCF77 Master Wall Clock – [Link]

Read multiple switches using ADC


by Les Hughson @

The ATMega168 is a great general purpose 8-bit AVR microcontroller from Atmel. It has 23 GPIO pins, but sometimes (as I have found) you can run out of I/O pins as your design grows. This happened to me recently when, of the 23 GPIO pins available, 2 were taken up by an external ceramic resonator, 1 for the reset line, 3 for serial coms, 14 for the LCD, and 3 for RGB LED control. This used all 23 GPIO pins, with none left for the four buttons I needed. What to do? This Design Idea has the solution.

A close look at the ATMega168 data sheet revealed that the I/O pins available on the 28-pin DIP package and on the 32-pin TQFP package are not all the same. On the TQFP package, there are an additional pair of VCC & GND pins and an additional two ADC input pins on top of the advertised 23 GPIOs. So if I could read my 4 buttons with these extra ADC inputs, all would be OK and the design would be saved.

Read multiple switches using ADC – [Link]

Samsung Researchers Nearly Double Lithium-ion Battery Capacity


by GardenState @

Silicon is receiving considerable attention as an active material for next- generation lithium-ion battery anodes because of its gravimetric capacity–a measure in mAh/g of the total charge capacity stored by the cell or battery, per gram of the battery’s weight.

Unfortunately, the large volume change of silicon during charge–discharge cycles has in the past weakened its competitiveness. Recently, however, a research group from Samsung reported in the publication Nature Communications that using direct graphene growth over silicon nanoparticles without silicon carbide formation resulted in a near doubling of run-time by expanding energy density– the amount of stored power in a given area — to 1.8 times that of current batteries.

Samsung Researchers Nearly Double Lithium-ion Battery Capacity – [Link]

Rohde & Schwarz HMC8043 PSU: Review and Teardown


by Martin Cooke @

Bench power supplies aren’t really pieces of kit that get your pulse racing, they just sit there doing their job, in some cases giving gentle background heating to keep the lab warm in the winter and providing enough ballast to stop your bench wobbling about too much. The traditional bench top power supply always came with a sturdy handle on the top to give you a clue that inside is some serious ironwork and that this beast is going to be heavy. But that was all yesterday; buy a power supply today and it doesn’t look much different from any other piece of test gear; covered in buttons with a TFT display and the chances are you can wrap your hand around it and pick it up one-handed. That’s true of the HMC8043 three channel 100-watt bench power supply from Rohde & Schwarz I received for reviewing.

Rohde & Schwarz HMC8043 PSU: Review and Teardown – [Link]

Supercomputing Video Card for Personal Computer

This circuit is designed for dedicated graphic display applications. It shows the basic configuration of personal computer hardware and functions. It is a generic type of a processing unit that handles display and improves image quality. It also manages data transfer from flash drives and other serial devices such as computer mouse and keyboard.

The design is comprised of different parts that serve different functions. The PX1011B-EL1 device is a high-performance, low-power, single-lane PCI Express electrical PHYsical layer (PHY) that handles the protocol and signaling between FPGA and Motherboard. The FPGAs or field-programmable gate arrays serves as the main processors of this designed circuit. It is configured to process data at very fast rate and control bidirectional data buses including I/Os for the display. It has memory interfaces that handle the SRAM, DRAM, and Flash memory. It also has accelerator functions that handle displays and other monitoring applications and fixed peripherals that handle GIGe, USB, CAN, I2C, SD, UART and GPIO. The Static Random Access Memory (SRAM) device is a memory component that is used as a cache memory of FPGA. The Dynamic Random Access Memory (DRAM) stores bits of data in separate capacitor within an integrated circuit. It also serves as the main memory element so that the FPGA’s work will be lessened. The PTN36242L is a dual port SuperSpeed USB 3.0 redriver IC that enhances signal quality by performing receive equalization on the deteriorated input signal followed by transmit de-emphasis maximizing system link performance. The USB microcontroller is a programmable interface chip that is used to integrate USB 2.0 port. The USB 2.0 is provided for longer cable length applications. The PCA24S08A is Electrically Erasable and Programmable Read-Only Memory (EEPROM), which allow you to reprogram the VID/PID for the USB device Identification.

The CBTL06122AHF device is a six-channel (‘HEX’) multiplexer for display port and PCI express Gen2 applications and provides four differential channels capable of switching and multiplexing applications. The PTN3361B device is a high-speed level shifter which converts four lanes of low-swing AC-coupled differential input signals to DVI v1.0 and HDMI v1.3a compliant open-drain current-steering differential output signals, up to 1.65 Gbit/s per lane and it is connected to a HEX multiplexer. The design is practically excellent since it considers the components’ cost. It can be used for commercial applications and as a reference for CPU development. It is also suitable for data management applications such as accounting or inventory.

Supercomputing Video Card for Personal Computer – [Link]

LTC6268-10 – 4GHz Ultra-Low Bias Current FET Input Op Amp


The LTC6268-10 is a single 4GHz FET input op amp for high dynamic range and high speed transimpedance amplifier (TIA) applications. This new decompensated amplifiers extend the speed and dynamic range capabilities of this ultralow bias current op amp family for applications with a gain of 10 or higher. Input bias current is 0.9pA max over the 40°C to 85°C temperature range and just 4pA max over the entire 40°C to 125°C temperature range. Wideband voltage and current noise are 4nV/√Hz and 7fA/√Hz, respectively. With 0.45pF input capacitance and 1000V/μs slew rate, the LTC6268-10 is well suited for photodiode and photomultiplier (PMT) circuits, high impedance sensor applications and for driving analog to digital converters (ADCs). The part is also available as a dual op amp (LTC6269-10) and in unity gain stable options (single LTC6268 and dual LTC6269).

LTC6268-10 – 4GHz Ultra-Low Bias Current FET Input Op Amp – [Link]


Simplify DC-DC Converter Characterization


by Mary Anne Tupta @

DC-DC converters are widely used components that convert DC power from one voltage to another, producing a regulated output voltage. These devices are used in many electronic products, including laptops, mobile phones, and instrumentation. Like any device, DC-DC converters need to be characterized by manufacturers and by engineers evaluating them for a design.

Given the increased pressure to develop products that consume less power, design engineers are looking for ways to increase power conversion efficiencies. Thus, numerous measurements are required to characterize the electrical parameters of DC-DC converters.

Simplify DC-DC Converter Characterization – [Link]