A tale of two USB-RS232 adapters

There are a number of USB-RS232 adapters available, among them Silabs, FTDI, Prolific and WCH.

The Silabs CP series adapters have been reliable but not very widely used.

The Prolific adapters are, well, prolific… but given their major compatibility problems and poisoned drivers, they are not a good choice.

FTDI was a good choice until they distributed through Microsoft Windows Update their device poisoning trick to disable chips they thought counterfeit… though they seemed to have backed away from that action.

The new kid on the block is an adapter by Chinese company WCH, chips that appearing in lots of low cost devices, eg Arduino Nano clones with WCH adapters instead of FTDI selling for around A$3+ on eBay whereas the FTDI equipped Nanos are more like A$12.

This article compares the WCH  CH340G and  FTDI FT232RL.

2USBRS232Above are two inexpensive adapters for Arduino boards, the upper one is FTDI based at A$8 each (inc post), and the lower one WCH based at 3 for $3.60 (inc post). Continue reading A tale of two USB-RS232 adapters

Arduino HMC5883 magnetometer – a tutorial

This tutorial shows how to explore an inexpensive HMC5883 3 axis magnetometer module with Arduino.

The magnetometer module can be purchased on eBay at very low cost (<$3), and is an ideal educational project for the budding Arduino practitioner.

It is an ideal low cost project for a first exploration of explore I2C, and the basis for a digital compass. This particular module breaks out DRDY which is useful for interrupt driven applications.

Fig 1
Fig 1

Fig 1 shows the test setup:

  • at the top is a Arduino Pro 328 with Opti bootloader and FTDI adapter for programming;
  • middle is the HMC5883L module; and
  • bottom is a Logic Shrimp for logic tracing.

Continue reading Arduino HMC5883 magnetometer – a tutorial

Arduino stepper motor – a tutorial

This tutorial shows how to explore an inexpensive stepper motor and driver board using an Arduino and included stepper library.

The stepper motor and driver board can be purchased on eBay at very low cost, and is an ideal educational project for the budding Arduino practitioner.

Fig01
Fig 1

Fig 1 shows the test setup:

  • at the top is a Arduino Pro 328 with Opti bootloader and FTDI adapter for programming;
  • middle is a Logic Shrimp for logic tracing;
  • bottom left is a 28BYJ-48 stepper motor; and
  • bottom right is a driver module based on UNL2003.

Continue reading Arduino stepper motor – a tutorial

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