Edward Mallon writes: While I loved the Nokia 5110 LCD’s readability in full sun, the pressure sensitivity was a real problem for the underwater units. So I started noodling around with some cheap OLED screens from eBay. With the exception of the init & XY functions (which are more complicated on the 1306 controller) the […]
Category Archives: tutorials
ESP32 AM radio transmitter
A how-to on making a simple AM radio transmitter using the ESP32 microcontroller by Bitluni: AM Radio transmissions are based on a carrier signal which is modulated by the audio signal. It’s a very basic principle but prone to noise from the environment. Using the ESP32 it is really simple to generate an analog signal […]
Build a Multisensor Shield for ESP8266
Rui Santos has a great write-up on building a Multisensor Shield for ESP8266, that is available on GitHub: In this project you’ll discover how to design and create a Multisensor Shield for the ESP8266 Wemos D1 Mini board. The shield has temperature sensor (DS18B20), a PIR motion sensor, an LDR, and a terminal to connect […]
Tutorial: Using the Arduino’s internal EEprom to store calibration data and LCD screen fonts
Edward Mallon writes: This is a follow-up to our post about using Nokia 5110 screens on three unused analog lines with shift-out. That saved me from messing with the hardware SPI bus which we reserve for the SD cards. A secondary benefit is that the code is really lean, on the order of about 250 […]
How to use I2C LCD with ESP32 on Arduino IDE
A how-to on using an I2C LCD display with the ESP32 using Arduino IDE from Random Nerd Tutorials: This tutorial shows how to use the I2C LCD (Liquid Crystal Display) with the ESP32 using Arduino IDE. We’ll show you how to wire the display, install the library and try sample code to write text on […]
Dual ultrasonic sensors combine for 2D echolocation
A how-to on making a Dual-sensor ultrasonic echo locator by lingib, project instructables here: This instructable explains how to pinpoint the location of an object using an Arduino, two ultrasonic sensors, and Heron’s formula for triangles. There are no moving parts. Heron’s formula allows you to calculate the area of any triangle for which all sides are […]
ESP32 with multiple DS18B20 temperature sensors
Guide to ESP32 with multiple DS18B20 temperature sensors from Random Nerd Tutorials: This guide shows how to read temperature from multiple DS18B20 temperature sensors with the ESP32 using Arduino IDE. We’ll show you how to wire the sensors on the same data bus to the ESP32, install the needed libraries, and a sketch example you can […]
EEPROM rotation for ESP8266 and ESP32
Xose Pérez over at Tinkerman writes: The Arduino Core for ESP8266 and ESP32 uses one SPI flash memory sector to emulate an EEPROM. When you initialize the EEPROM object (calling begin) it reads the contents of the sector into a memory buffer. Reading a writing is done over that in-memory buffer. Whenever you call commit […]
Amiga 500 power supply build
A how-to on building an Amiga 500 power supply from Inkoo Vintage Computing: The power supply of my Amiga 500 is a bit unreliable. I’ve had some issues with the machine where the PSU could be the culprit, so I thought that it would be better to get a new power supply. There are used Amiga 500 power […]
Video tutorials: Building the Arduino based data loggers
From the comments on our Arduino data logger post: A visiting researcher dropped by our humble basement workshop with questions about the physical skill level students would need if they added one of our DIY data loggers to their environmental curriculum. I figured the easiest way to cover that was to simply build one, while they […]
Tutorial: Setting up a low cost QRP (FT8, JT9, WSPR etc) monitoring station with an RTL-SDR v3 and Raspberry pi 3
A detailed tutorial on how to set up a cheap QRP monitoring station using an RTL-SDR V3 and a Raspberry Pi 3 from rtl-sdr.com This tutorial is inspired by dg0opk’s videos and blog post on monitoring QRP with single board computers. We’ll show you how to set up a super cheap QRP monitoring station using an […]
5 LDO regulator considerations other than voltage and current
James Lewis over at Bald Engineer writes, “For an AddOhms series, I created a DIY Arduino I am calling the “Pyramiduino.” It is an ATmega328p based board in the shape of a triangle. Other than being cute, the shape does not offer any other benefit. The design features a 3.3 volt LDO Regulator, which is […]
Arduino time attendance system with RFID
A how-to on building a time attendance system with MFRC522 RFID Reader and Arduino from Random Nerd Tutorials: Before getting started it’s important to layout the project main features: *It contains an RFID reader that reads RFID tags; *Our setup has a real time clock module to keep track of time; *When the RFID reader reads an […]
DIY Moteino guide
Felix writes, “I posted a short illustrated guide for making your own Moteino from SMD components. It also includes details how to burn the bootloader and fuses. Check it out here. Thanks and credit goes to forum user LukaQ for his contribution of the images and test sketches in this guide! See the full post […]
How servo motors work and how to control servos using Arduino
Dejan Nedelkovski over at HowToMechatronics shared detailed tutorial on how servo motors work and how to control servos using Arduino and PCA9685 PWM driver: There are many types of servo motors and their main feature is the ability to precisely control the position of their shaft. A servo motor is a closed-loop system that uses […]
Why electrolytic capacitors are actually kinda shitty
Afroman writes, “Electrolytic capacitors are common, but knowledge of their limitations is uncommon. A demonstration is shown highlighting the difference in performance between electrolytic and ceramic capacitors in power supplies. Other topics discussed in the video: Electrolytic capacitor construction, ceramic capacitors, ESR, ESL, impedance curves, why “0.1uF”, and more.” Via Afrotechmods. Check out the video after […]
Alexa (Echo) with ESP32 and ESP8266 – Voice controlled relay
Rui Santos writes, “In this project, you’re going to learn how to control the ESP8266 or the ESP32 with voice commands using Alexa (Amazon Echo Dot). As an example, we’ll control two 12V lamps connected to a relay module. We’ll also add two 433 MHz RF wall panel switches to physically control the lamps.” More […]
DIY Arduino PCB Pryamiduino
A how-to on designing a DIY Arduino PCB Pryamiduino from Bald Engineer: Continuing the DIY Arduino tutorial series, this AddOhms episode shows how to create a PCB in KiCad. I make a joke that the original design was a rectangle, which I found boring and pointless. So instead, I designed a triangle to give the board […]
Debug SONOFF AC relay with a thermal camera
James Lewis shares his experience in debugging SONOFF AC relay with a thermal camera: The clever solution seemed to be clever, at least for a few minutes. Suddenly the light turned off. I thought maybe there was a timeout for the manual button. Annoying, but workable. The lamp remained off for about another 2 minutes when […]
ESP8266 Wi-Fi button – DIY Amazon dash button clone
Rui Santos over at Random Nerd Tutorials posted a step by step guide on building an ESP8266 Wi-Fi button: In this project you’re going to build an ESP8266 Wi-Fi Button that can trigger any home automation event. This is like a remote control that you can take in your pocket or place anywhere that when […]