Open source temperature controller

Michael writes:

My name is Karel and I’m creating an open source temperature controller. Please see the FAQ for open source licenses. I initially started this project because I make my own prototype PCBs at home, using the toner transfer method, and found out the laminator I use, a Scotch TL-901, doesn’t run hot enough and it took several passes to get the board hot enough. Instead of taking the time to reverse engineer the control board that was in the laminator, I decided to make my own.

After I finished the first prototype, I quickly realized there could be a lot of uses other than controlling a laminator. Some that came to my mind included using the board to modify a window A/C to be used in a walk in cooler, measuring inside and outside temp to control a green house, using it to control an aquarium heater, or even controlling egg hatching. I’m sure there are lots of other uses that the open source community will find.

Open source temperature controller – [Link]

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XR-2206 Function Generator

Charalampos Andrianakis writes:

When i was using operational amplifiers at school lab i wanted a function generator at home to play with and work on circuits with Op Amps for better understanding. So i found on the internet a free function generator circuit which uses the IC XR-2206, i printed the PCB with my UV epxosure box, i bought an enclosure box, i put everyhting inside and here is the result.

The function generator can generate Square, TTL, Sine and Triangle waveforms from 1Hz to ~1Mhz with Voltage regulation to Square Sine and Triangle waveforms.

XR-2206 Function Generator – [Link]

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GSM/GPRS Autonomous Weather Station (Tracking System)

Charalampos Andrianakis writes:

Autonomous live tracking weather station. It takes (analog/digital) measurements and sends them to a web server over GPRS. Adding a battery and a solar station you can make it fully autonomous. It supports up to 3 Analog or Digital inputs. The main brain is the PIC 16F877A which also drives the SIM900/300 GSM module which is placed in the back of the PCB.
The main purpose of this project is to take wind flow measurements of different locations and store them in a database remotely. By this you know if the locations are appropriate for future installation of wind generators.

The data send from GSM to Web server with GET requests which isn’t the safest and best way but its an easy way to make it work. The example code you can find at the github is a very simple example and has no security responsibility.

GSM/GPRS Autonomous Weather Station (Tracking System) – [Link]

Arduino KitchenTimer

kalshagar.wikispaces.com writes:

Goal is to replace this Ikea super cheap timer that works … well, as good as something manual that you paied less than 200 JPY (less than 2 euro). Not precise, sometimes doesn’t ring, or ring just the blink of an eye, so easy to miss…

The new timer will:

  • Have a graphical LCD (bought one one year ago, never used it, needed a pretext, so…)
  • Work on battery (1x 9v battery)
  • Play music when it’s time
  • Use a speaker and amp
  • Possibly use a YMZ294 ?
  • In fact something else but much better…
  • Have an on/off system with a push-button, not a open/close switch In fact a tilt switch
  • No arduino, but a simple atmega 328 (more than sufficient)
  • Keep me busy a few days while allowing me to use some parts I bought long time ago and create a un-reasonable and out of price kitchen timer

Arduino KitchenTimer – [Link]

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4-input mini Logic Analyzer

A mini Logic Analyzer wich has 4 inputs, it’s portable (55×65 mm), battery powered and at the moment can capture data upto 100kHz. Vassilis Serasidis writes:

This mini Logic analyzer is a tool for you to watch on LCD the logic transitions 0 or 1 of a digital data signal. A digital data signal can be found on the output pin of TSOP-1730 Infrared Receiver, on the Transmit and reveive pins of MAX-232 chip (RS-232), on Clock and Data pins of I2C data bus and many more electronic components. This circuit is so far limited upto 100 kHz digital signals but this will be changed with a future firmware update.

4-input mini Logic Analyzer – [Link]

Simple Nokia LCD breakout board

 

Arup wrote a guest post about his Nokia LCD breakout board:

I designed a simple Nokia LCD Breakout board which allows you to interface any Nokia 6100 compatible display to microcontroller like PIC and AVR. The board itself provides 6.8volts for the backlight by a simple boost converter built up using a common 555 timer IC. There’s a switch to choose whether you want to work with 5V logic, or with 3.3V logic. [via]

Simple Nokia LCD breakout board – [Link]

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2A automotive step-down converter

MAX16974 High-Voltage, 2.2MHz, 2A Automotive Step-Down Converter with Low Operating Current – [via]

  • Wide input voltage range (3.5V to 45V) allows seamless operation from cold crank to load dump
  • Low quiescent current meets tight power budgets
  • High-frequency operation eliminates AM-band radio interference

2A automotive step-down converter – [Link]

The single NPN transistor audio preamp

Hack a Week’s new project this week is a single NPN transistor audio preamp – [via]

Here’s a great little project that goes well with the LM386 audio amp. It’s a good first time transistor project because it’s simple and demonstrates the common emitter class A amplifier circuit with only six components in the signal path.

The single NPN transistor audio preamp – [Link]

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1.2 kA motor driver circuit based on the PIC16F877

rsdio writes: This thing puts out so much torque that it has to be run at 3/4 power to avoid slipping the clutch! – [via]

Features: Programmable current limit 100-1200 motor amps, automatic over-temperature current limit cut-back, water-cooled copper heat sink, low-loss IGBT modules, and motor overspeed limit.

Processor: Microchip PIC 16F877 This small yet powerful microcontroller runs at 5 MIPS and 20MHz with 8kb of onboard program FLASH memory. It also has two onboard 10-bit PWM generators, eight 10-bit ADC channels, and a UART interface.

1.2 kA motor driver circuit based on the PIC16F877 – [Link]

tinyDino – smallest Arduino board

Jaanus has been working on a subminiature Arduino clone which be believes is THE smallest – [via]

Everybody are making Arduino clones. So I thought I should make THE smallest. I took smallest package atmega88 – qnf28 (5mm x 5mm). Routed smallest possible resonator and as much pads as i could fit on in.

His design provides SPI, UART, one LED and breaks out 4 analog and 1 digital IO pins.

tinyDino – smallest Arduino board – [Link]