Using BMP180 for temperature, pressure and altitude measurements

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Raj from Embedded Lab has posted a comprehensive tutorial on how to use BMP180 for temperature, pressure, and altitude measurements:

The BMP180 is a new generation digital barometric pressure and temperature sensor from Bosch Sensortec. In this tutorial, we will briefly review this device and describe how to interface it with an Arduino Uno board for measuring the surrounding temperature and pressure. We will also discuss about retrieving the sensor altitude from its pressure readings.

Details at Embedded Lab homepage.

App note: LCD screens don’t flicker – or do they?

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An old application note from Intersil on comparison of CRT and LCD regarding display flicker. Link here (PDF)

When comparing CRT to LCD screens, one of the most popular differences is the issue of flicker. It is a common assumption that CRT screens flicker while LCD screens do not. In truth, both screens have some amount of flicker. The mechanisms are different and methods for correction have varying amounts of success. This appnote presents the cause of flicker in LCD screens and offers a solution for avoiding flicker by using our ISL45041/2 LCD Module Calibrator in LCD panels.

App note: Interfacing AT84AD001B dual 8-bit 1 Gsps ADC and AVR ATmega128L

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e2v’s application note interfacing their 1 Gsps 8-bit ADC to AVR. Link here (PDF)

With its smart feature (3-wire serial interface), e2v’s AT84AD001B dual 8-bit 1 Gsps ADC provides you with digital control over various functions offered with the dual ADC: calibration, gain and offset adjustments, DMUX ratio selection, analog and clock input mode, and partial or full standby mode.

This digital control via the 3-wire serial interface can be managed using Atmel’s ATmega128L AVR. The aim of this application note is to provide you with the relevant information for interfacing these two devices.

App note: Designing VCNL3020 into an application

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An app note from Vishay: Designing VCNL3020 into an application (PDF!)

The VCNL3020 is a proximity sensor with I2C interface. It combines an infrared emitter, PIN photodiode, and signal processing IC in a single package with a 16 bit ADC. With a range of up to 20 cm (7.9″), this stand-alone, single component greatly simplifies the use and design-in of a proximity sensor in consumer and industrial applications because no mechanical barriers are required to optically isolate the emitter from the detector. The VCNL3020 features a miniature leadless package (LLP) for surface mounting in a 4.9 mm x 2.3 mm package with a low profile of 0.83 mm designed specifically for the low height
requirements of smart phone, mobile phone, digital camera, and tablet PC applications. Through its standard I2C bus serial digital interface, it allows easy access to a “Proximity Signal” measurement without complex calculations or programming. The programmable interrupt function offers wake-up functionality for the microcontroller when a proximity event occurs which reduces processing overhead by eliminating the need for continuous polling.

High voltage power supply for Nixie tubes

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Limpkin has published a new build: a high voltage power supply for Nixie tubes

For quite a while I’ve had this project idea in the back of my head that would involve using many Nixie tubes.
These funny looking cold cathode displays were actually introduced during the 1950s and unfortunately need quite a high voltage to work (from 100V to 180V depending on the type). This meant that I had to find an easy, cheap and (if possible) not dangerous solution to power them.

Project info at Limpkin’s blog.

USB to ADB converter project

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Steve at Big Mess o’ Wires has been experimenting with USB to ADB converter.  He writes:

It’s time for a new progress report on my USB to ADB converter project! My goal is to design a simple PIC32 device that enables USB keyboards and mice to be used with vintage ADB-based Macintosh and Apple IIgs computers. You can read my earlier reports here: 1, 2, 3, 4, and 5. I don’t know when I’ve ever spent so much time investigating the feasibility of a project, without actually doing the project. Hopefully all this preparation will pay off.

More info at Big Mess o’ Wires project page.

Bringing a vintage telegraph into the digital age

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Kyle Gabriel writes:

I recently inherited a key on board (KOB) telegraph that my late grandfather used to practice Morse code with when he was a kid (Figure 1). A little bit of curiosity of how it would work and a little bit of displeasure from seeing it sit and collect dust, I began a journey to resurrect the old machine and develop some software to bring it into the digital age.

More details at Kyle Gabriel’s blog.

Check out the video after the break.

Soldering pen

In this video Hans Peter demonstrates his soldering pen project:

I’ve tried to compile a list of the things I still need to finish (not in order):
– making a stand
– making a casing
– make temperature control via buttons
– slow down LED pulse
– general cleanup (in HW and FW)

Project info at embryonic.dk site.

Get ready for MPLAB Express, throw away your Arduino

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Chas from iradan.com writes:

I credit the maker movement with bringing electronics back from the crusty old and lonely electronics hobby back into the main stream. The Arduino is the micro of choice for this army of makers and I conceded it made sense… you install the IDE, plugged in your board into the USB port and a couple clicks later and you have an LED blinking.. the most exciting blinking LED you’d ever seen in most cases. I stuck with the PIC micros because I didn’t see any need to put back on the training wheels.
I got invited to a conference call earlier this week as they rolled out MPLAB Express. I almost passed the email up as spam, I’m glad I didn’t… a quick half hour later and I was in shock. Microchip is now relevant in the hobbyist realm.. They just leapfrogged over Arduino in usability for the beginner. They just released Microchip MPLAB Express a new, free, online cloud-IDE. Write your code (or pick a sample), press the compile button and the .hex file downloads.. DRAG AND DROP the .hex file on to the dev board. … the dev board looks like a plain flash drive… just drag and drop and the code is automatically programmed to the device… DRAG AND DROP.. brilliant.

Details at iradan.com homepage.