A Simple Arduino Metal Detector

Introduction In the early-days of metal-detecting, a simple type of metal-detector called a BFO (Beat Frequency Oscillator) detector was commonly used. It doesn't work as well as more modern designs, but it's quick, and easy, to build, and you may find it good enough for beach-combing for coins or rings. A BFO detector traditionally consists… Continue reading A Simple Arduino Metal Detector


Flashing the STM32F103 using a Raspberry Pi 3

 Preparing the Raspberry Pi 3 Install the stm32flash utility: git clone https://git.code.sf.net/p/stm32flash/code stm32flash-code cd stm32flash-code sudo make install Move the high performance UART from the Bluetooth device to  the GPIO pins: sudo nano /boot/config.txt Add the following line: dtoverlay=pi3-miniuart-bt Edit cmdline.txt: sudo nano /boot/cmdline.txt Remove the following text in cmdline.txt to prevent a console from running… Continue reading Flashing the STM32F103 using a Raspberry Pi 3

Class D Amplifier for the Arduino

The pulse-width-modulated output of an arduino is often used in conjunction with a small piezo-electric speaker to create tones and music. This simple approach works well; but if you try to scale up this approach and use a larger speaker, you'll find the power output of the digital IO pin is not sufficient to drive it properly.  To drive a… Continue reading Class D Amplifier for the Arduino