Arduino + Serial (ASCII)

January 10, 2017

Microcontrollers operate on +3.3Vdc or +5Vdc relative to GND typically.  Digital electronics consider a signal of +5Vdc (or +3.3Vdc) HIGH and a signal of 0Vdc LOW. Arduino microcontrollers treat voltages on a digital I/O pin above +0.7Vdc as HIGH and voltages below +0.3Vdc as LOW.  If a digital I/O pin is not connected, electrostatic discharge […]

Arduino + HC-SR04

November 4, 2016

Description The HC-SR04 ultrasonic sensor uses sonar to determine distance to an object like bats do. It offers excellent non-contact range detection with high accuracy and stable readings in an easy-to-use package. From 2cm to 400 cm or 1” to 13 feet. Its operation is not affected by sunlight or black material.   Acoustically soft […]

Arduino + WS2812

November 2, 2016

Description You can purchase long flexible strips of small surface mounted LEDs that come on a spool.  You can cut the strip to length at the cut marks.  You can solder strips together by using the solder pads. There are a number of different type of SMD (surface mounted device) LEDs available: The most common […]

Arduino + Mains power (433MHz TX + Safe)

November 1, 2016

Description I have been warning you to not open or manipulate any mains powered electrical equipment.  Do NOT interface an Arduino board with any mains power cabling, components, etc.  However, rather than telling you what you can’t do, the polite thing to do would be to at least provide you with a solution how you […]

Arduino + Relay

October 30, 2016

Warning Do NOT use this tutorial to connect a relay to 230Vac mains power.  I have blown the cap of a LED by connecting it directly between +5Vdc and ground once.  I have melted an electrolytic capacitor by connecting it to a voltage higher than it was rated for.  There are not too many people […]

Arduino + Safety

October 30, 2016

Electrical safety considerations This article is a strong warning to not open or manipulate any mains powered electrical equipment.  Do NOT interface an Arduino board with any mains power cabling, components, etc. This document provides some basic guidelines how to make electronics equipment electrically safe.  If anything I hope you will learn something from this. […]

Arduino + DS1307

October 28, 2016

Description A Real Time Clock (RTC) is basically just like a watch – it runs on a battery and keeps time for you even when there is a power outage.  Using an RTC, you can keep track of long timelines, even if you reprogram your microcontroller or disconnect it from USB or a power plug. […]

Arduino + Stepper (A3967) EasyStepper

October 26, 2016

Description Bipolar stepper motors always have only 4 wires.  They require a dual H-bridge to drive them.  Bipolar motors offer increased torque compared to unipolar motors.  Flyback diodes are required to prevent voltage spikes when the power to the coil is turned off and the stepper motor acts like a generator briefly (back-emf). Note: You […]

Arduino + Stepper (L298N)

October 25, 2016

Description Bipolar stepper motors always have only 4 wires.  They require a dual H-bridge to drive them.  Bipolar motors offer increased torque compared to unipolar motors.  Flyback diodes are required to prevent voltage spikes when the power to the coil is turned off and the stepper motor acts like a generator briefly (back-emf). Note: You […]

Arduino + Stepper (ULN2003A)

October 25, 2016

Description Unipolar stepper motors have 5, 6 or 8 wires.  They do not require a dual H-bridge to drive them.  Instead, you can use a transistor for each phase and a flyback diode to prevent voltage spikes when the power to the coil is turned off and the stepper motor acts like a generator briefly […]