Blog
Build logs, project notes, and write-ups from the workshop.
- How to Use the L298N Motor Driver with Arduino — Wiring + PWM Speed Control Everything you need to wire and code the L298N dual H-bridge motor driver with Arduino — IN1-4, ENA/ENB, common ground, PWM speed control, and the stall-current trick nobody documents.
- The $15 Amazon Arduino Robot Chassis — Assembly Walkthrough A two-wheel-drive acrylic robot chassis from Amazon costs $15 and includes motors, wheels, a caster, encoder discs, and hardware. Add ~$15 in electronics and you have a complete robot platform.
- How to Measure Distance with an Arduino and HC-SR04 Ultrasonic Sensor The HC-SR04 is dollar-store radar for your Arduino — four pins, a library, and a few lines of code give you distance readings in centimeters. Here is how to wire it, code it, and deal with its quirks.
- How to Use a Real Time Clock with Arduino — DS1307 RTC Tutorial The Arduino loses track of time the moment you unplug it. The DS1307 RTC module fixes that with a coin-cell backup and an I2C interface simple enough to share a bus with your LCD. Full walkthrough from address scan to LCD display.
- How to Use a Keypad with Arduino — Matrix Wiring and the Keypad Library A 4x4 membrane keypad gives you 16 buttons through only 8 Arduino pins. This post covers the matrix logic, the Keypad library, wiring, and how to display keypresses on an I2C LCD.
- How to Connect Multiple LCD Displays to One Arduino The PCF8574 I2C backpack on cheap 1602 LCDs has three address jumpers — A0, A1, A2 — giving you 8 unique addresses. That means 8 LCD displays on two Arduino pins. Here is the address chart, the jumper settings, and the sketch to drive all of them.
- How to Use a 1602 I2C Serial LCD Display with Arduino The parallel 1602 LCD needs 12 wires and a headache. The I2C version needs four. Here is how to wire it, install the library, and get text on screen in under ten minutes.
- How to Power a Servo Motor from an External Supply with an Arduino An SG90 micro servo can stall at 650 mA — over 30 times what an Arduino I/O pin can safely provide. Here is why you need an external power supply for any servo, how to wire one, and the one connection that makes it work: common ground.
- How to Use a PIR Sensor to Detect Motion The HC-SR501 PIR sensor is one of the most practical components you can add to an Arduino project. Three wires, a handful of configuration options, and you have reliable motion detection for under $2.
- How to Upgrade RAM in a 2019 iMac 27-Inch — Fast and Easy The 2019 27-inch iMac has four user-accessible RAM slots. Apple charges a fortune for factory upgrades, but a $138 OWC kit takes the machine from 8GB to 32GB in about five minutes.