Arduino thermistor thermometer – a tutorial

This project was designed ad-hoc as a learning exercise for a friend who ‘needed’ to acquaint himself with Arduino.

What better than a practical exercise that demonstrates some key advantages and disadvantages of the Arduino environment.

The project was a simple digital thermometer to display normal environment air temperature, say from -20° to 50° using common and inexpensive Arduino hardware with firmware developed on the free Arduino IDE, all using hardware that was on hand. Continue reading Arduino thermistor thermometer – a tutorial

I2C – LCD interface – Type 2

A range of inexpensive serial to Hitachi style LCD interfaces are becoming available.

This article describes the settings for one sold by eshoppingcity1 (and others) on eBay (about A$6 for 5 inc post at the time of writing but they are getting cheaper). It uses the Philips PCF8574T I2C expander chip which is supported by the user developed Arduino LCD Library V1.2.

Lc2I2c10 Continue reading I2C – LCD interface – Type 2

Fox flasher MkII

Flashing LED driver using an ESC described a LED driver for an animal deterrent using a repurposed brushless DC motor electronic speed controller.

This article describes a simpler implementation based on a Chinese 8051 architecture microcontroller, the STC15F104E.

ff201

Above, the schematic. A very simple circuit with just a handful of electronic components (one capacitor, two resistors, one LDR, one Polyswitch, 4 x LEDs and the MCU). Continue reading Fox flasher MkII

Time to get some experience with 32bit microcontrollers

After almost 50 years working with 8bit microcomputers and microcontrollers, I thought it about time to get my hands dirty on some 32bit microcontrollers.

The plan is to investigate two streams, one ST Microcontoller based and one ATMEL based, both ARM architecture. Continue reading Time to get some experience with 32bit microcontrollers

Capturing the AVR hex file built by Arduino on Windows

One often sees enquiries by people trying to save the hex file made during the Arduino build process.

It is not trivial, as in their wisdom, Arduino hides these details, and builds the hex file in a randomly named temporary directory for each IDE which it deletes when the IDE is closed.

There are times when you may want to save the hex file, perhaps to load it without a bootloader or using a non-supported bootloader, Flashing LED driver using an ESC was just such a project. Continue reading Capturing the AVR hex file built by Arduino on Windows

Simple Morse beacon keyer updated 2014/03/01

W4HBKgrab001

Above is a clip from W4HBK’s 40m grabber today, the signal is VK2OMD running 5W QRSS6 over a 14,700km path. We can infer (Duffy 2012b) from the 15dB S/N in that capture in 0.25Hz noise bandwidth, that in an 800Hz CW filter for say -5dB S/N (threshold of copy) we need 15dB more signal, or 160W for reliable copy. (Less power may be adequate for very short QSOs at the peak of fade cycles.)

Continue reading Simple Morse beacon keyer updated 2014/03/01

I2C – LCD interface – Type 1

A range of inexpensive serial to Hitachi style LCD interfaces are becoming available.

This article describes the settings for one sold by NYplatform on eBay (about $25 for 5 inc post at the time of writing – but they are getting cheaper). It uses the Philips PCF8574T I2C expander chip which is supported by the user developed Arduino LCD Library V1.2.

IICLCD

Continue reading I2C – LCD interface – Type 1