Panel switch wiring

Thursday, October 2, 2014

Temperature Data Logger 4 Channel Four Channel

Heres a temperature data logger circuit, an 8-pin microcontroller based circuit for temperature data logging via the serial port of any computer from between 1 and 4 remote digital temperature sensors, DS1820/DS18S20 made by Dallas.

Features of the Temperature Data Logger are are follow:

Provides realtime data via the serial port.
Interfaces up to 4 x DS1820 sensors.
Accuracy to 0.5 degrees centigrade
Fahrenheit scale selected by a jumper
No external power required
Data stream easily logged & processed.
Over 200m distance for each sensor

The sensors of temperature data logger may be located more than 200 yards from the PCB. Just check that the remote VDD is above 4.4Volts. Its recommends 10uF tantalum capacitors be placed across the power supply pins (not supplied) to minimise random errors and possibly get increased range.

Download :
- Circuit Schematic and Parts List
- Sensor Specs DS1820 DS18S20
- Software for Windows and DOS
- Source Code
- Terminal Emulator

Wednesday, August 27, 2014

MHz Oscillator using an ATtiny15 Wiring diagram Schematic

Most engineers will recognise the problem: Your schema needs a stable 1 or 2 MHz clock generator (in the author’s case it was for a Pong game using an old AY3-8500). A suitable crystal is not to hand so you cobble together an RC oscillator (there are plenty of diagram for such a design). Now it turns out that you don’t have exactly the right capacitor so a preset pot is add e d to allow some adjustment . Before you know it the clock schema is taking up more space on the board than you had hoped.

Providing the application does not demand a precise clock source a tiny 8-pin microcontroller may offer a better solution to the problem. It needs no additional external components and an old ATtiny15 can be found quite cheaply. Another advantage of the solution is that clock frequency adjustment does not involve changing external components and is not subject to component tolerances.

The microcontroller’s internal RC oscillator is already accurately calibrated to 1.6 MHz. With its inbuilt PLL, internal Timer 1 can achieve up to 25.6 MHz [2]. By configuring internal dividers the timer can output a frequency in range of roughly 50 kHz up to 12 MHz from an output pin. The difference between calculated and the actual output frequency increases at higher frequencies. A meaningful upper limit of about 2 MHz is a practical value and even at this frequency the deviation from the calculated value is about 15 %.

MHz Oscillator using an ATtiny15 Schematic

The schema diagram could hardly be simpler, aside from the power supply connections the output signal on pin 6 (PB1) is the only other connection necessary.The example program, written in Assembler is just 15 lines long! With a program this short comments are almost super fluous but are included for clarity. The code can be downloaded from the Elektor website [1].

The program only needs to initialise the timer which then runs independently of processor control to output the clock sign al . The processor can then be put into sleep mode to memory used up the remaining 99 % is free for use for other tasks if required.

The OSCCAL register contains a calibration byte which allows some adjustment of the CPU clock. This gives a certain degree of fine tuning of the output frequency. A recommendation in the Atmel data sheet indicates that the CPU clock frequency should not be greater than 1.75 MHz otherwise timer operation cannot be guaranteed.

The more recent ATtiny45 can be substituted for the ATtiny15. In this case the CK SEL fuses should be set to put the chip’s Timer 1 into ATtiny15- compatible mode [3]. After adjustment to the program it will now be possible to obtain a higher (or more exact) frequency from the timer, the ATtiny45’s PLL can operate up to 64 MHz.

Saturday, August 23, 2014

Build an Audio notch filter 2

Build an Audio notch filter 2 Circuit Diagram. With the schema shown here the response at one octave off tune is within 10% of the far out response: notch sharpness may be increased or reduced by reducing or increasing.respectively the 68 ohm resistor. Linearity tracking of R8 and R9 has no effect on notch depth. The signals at HP and LP are always in antiphase, notch will always be very deep at the tuned frequency, despite tolerance variations in R6-9 and C2, C3.

Build an Audio notch filter 2 Circuit Diagram

Friday, August 22, 2014

Simple Uninterrupted Power Supply in an IC

The Uninterrupted Power Supply in an IC . Cymbet Corporation announced the availability of the EnerChip™ CC CBC3105 smart solid state battery. The CBC3105 combines the award winning EnerChip battery with integrated input power conversion, battery management and regulated output capabilities. The Cymbet EnerChip™ CC is a smart rechargeable solid state battery Uninterrupted Power Supply (UPS in a Chip™) that provides power backup to microelectronic devices when main power fails. The EnerChip CC provides power supply monitoring and switches over to the internal solid state backup battery when the supply drops below a set threshold. The EnerChip CC product family can provide anywhere from several hours to several weeks of backup time.

Simple Uninterrupted Power Supply in an IC Circuit Diagram

The CBC3105 is an ideal solution for design engineers who need a compact device to back-up a Real Time Clock or Microcontroller during power failure where coin cell batteries or super caps will not work due to size, reliability, no battery doors, no battery replacement, battery disposal issues, or need for life-of-product power. The CBC3105 uses surface mount/reflow solder assembly and is RoHS tested-compliant.

The EnerChip CC device family can accomplish all this in a footprint as small as the CBC3105 4mm x 5mm x 0.9mm package that is priced as low as $0.50 in high volumes. The EnerChip CC CBC3112 and CBC3150 provide even more energy storage in similar small footprint packages. The CBC3105 can be purchased at Avnet, Avnet Abacus, Avnet Asia, Digi-Key, Mouser and Farnell.

Easy-to-Use Evaluation Kits for Power Backup Applications

Cymbet makes it easy to design EnerChips into new products by offering two EnerChip CC evaluation kits:

CBC-EVAL-05 EnerChip CC Evaluation Kit which contains everything needed to test EnerChip 12uAh and 50uAh thin film batteries, EnerChip CC CBC3112 and CBC3150 batteries with Integrated Battery Management, and to test multiple batteries in parallel. This kit will also include a CBC3105 evaluation board for experimenting with this device.
CBC-EVAL-06 Real-Time-Clock Evaluation Kit: includes a Microcrystal NV2123 Real-Time Clock device and a CBC3112 EnerChip CC for battery backup. This kit also includes a Windows based Graphical User Interface to set the clock & test operation in RTC back up and count-down modes.

Visit Cymbet at Design West/ESC Booth 2330 for UPS in a Chip Demos

At booth 2330 at Design West/ESC 2012 at the San Jose Convention Center March 27-29, 2012, Cymbet will demonstrate tiny footprint power backup solutions that give designers the ability to create optimized products. By providing all the functions of a UPS system in a single chip, the EnerChip CC batteries enable a new class of products that utilize life-of-product energy storage.