Rahul over at Xanthium has posted a tutorial on interfacing ATtiny with L293D: In this tutorial we will learn to interface L293D with ATMEL ATtiny microcontroller and control them bidirectionally.The microcontroller used here is ATtiny2313A which is interfaced to two L293D motor control chips for controlling upto 4 DC brushed motors.You can control upto 8 […]
Category Archives: how-to
“Hello world” in the BCPL language on the Xerox Alto simulator
Ken Shirriff writes: The first programming language for the Xerox Alto was BCPL, the language that led to C. This article shows how to write a BCPL “Hello World” program using Bravo, the first WYSIWYG text editor, and run it on the Alto simulator. The Xerox Alto is the legendary minicomputer from 1973 that helped […]
Adding a DHT22 temperature and humidity sensor to the Sonoff
Mikey writes: Just a few days ago I replaced the firmware on my Sonoff, and immediately after, I wanted more… After looking on their website, I found a version which also had a DHT11 sensor attached, and I then wanted to do something similar, just with a DHT22 for higher resolution (0.1C on a DHT22, […]
ESP8266 control panel upgrade
Evan writes, “While writing the article on multiplexing the esp’s inputs I came up with the idea of PWMing all the outputs at once by interrupting the path to ground with an n-FET. That’s actually not a bad idea, and I have an extra input on the analog MUX that I can use for a […]
GPRS module with M590 for SMS projects
From the comments on our earlier Neoway M590 GPRS tutorial post, the GPRS module with M590 for SMS projects by Nicu: In 1st part I present you few data about GPRS module with M590 chip and how send SMS from them. In 2rd part I send SMS from phone and SMS is received by GPRS module with […]
Running NodeMCU on a battery: ESP8266 low power consumption revisited
Tinkermax shows us how he reduce the current consumption of his v2 NodeMCU in deep sleep to < 50μA: Unfortunately, with all this added convenience comes the drawback of added power consumption, which continues even when the ESP8266 is in deep sleep. I measured 18mA to the NodeMCU board while the ESP8266 was in deep […]
Crystal motional parameters
Craig writes: Ever tried searching through your datasheets for the motional parameters of that quartz crystal you just bought? Good luck! Vendors simply don’t specify these parameters to general end users, and for most applications that’s OK. But for high Q oscillator and filter design, measuring and matching crystals can be important. This video discusses […]
Handheld CNC router repairs old CNC machine
In this video Ben Krasnow demonstrates how to use a handheld CNC router, the Shaper Origin, to make aluminum parts for his CNC mill. More details at Ben Krasnow’s blog.
HOW-TO: Add live websites to GIT without interruptions or security risks
Over at the DEV site we’ve been using GIT repositories hosted at BitBucket.org to push (deploy) changes to the live server instantly. It’s way slicker than uploading changed files by FTP, which has no roll back if something goes wrong. It also solves one of our China internet problems: routing to Bitbucket is much more […]
Using a Bus Pirate to connect to a Raspberry Pi
Scott Dixon describes on his website how he used the Bus Pirate to connect to a Raspberry Pi: The other day I found myself with a Rasberry Pi that I wanted to use but I had forgotten my FTDI UART cable. What I did have is my Bus Pirate v3.6 and I found it was […]
ESP8266 controlled with Android app (MIT App Inventor)
Rui Santos from Random Nerd Tutorials has posted a detailed tutorial on how to build an Android app using the MIT App Inventor software that allows you to control the ESP8266 GPIOs: More details at Random Nerd Tutorials homepage. Check out the video after the break.
Slider controller with auto-reverse and variable speed control
Paulo built a DIY electronic camera slider controller based on a small PIC microcontroller. It supports auto-reverse and variable speed: These motorized sliders share a common electronic controller design that provides speed control for the gear motor and also an auto-reverse feature using limit switches. In this article , I’ll go over the electronics and software for […]
Design and build a spin coater
In this video Ben Krasnow demonstrates how he designed and built a spincoater, and how you can use a similar motor control system in your own projects. More details at Ben Krasnow’s blog.
Modifying RAM SPD data
Zak Kemble wrote a post on his blog showing how he modified the RAMs Serial Presence Detect (SPD) data: Recently I brought some low-power Mini-ITX motherboards; a Gigabyte GA-N3050N-D3H and a Biostar N3050NH. These boards take SO-DIMM DDR3 RAM, the sort found in laptops. The boards are both pretty much the same, however the Gigabyte board lacks […]
Measuring SDR noise figure
David has written an article on measuring SDR noise figure: One number I wanted to know was the Noise Figure (NF) of the SDR. Mark has a bunch of SDRs so we got on a roll and checked out the NF on all of them. Now there are a lot of people playing with SDRs, but […]
DIY synth building, part 2
Here’s a video tutorial on making a sequencer circuits from Casper Electronics: Learn how to make a variety of musical pattern sequencers using a few common electrical components and a breadboard. See the part 1 video on building oscillators here.
Using “Ultracapacitors” as a power conditioner and ballast for transient high-power loads (or “How to run your HF rig from D-cells” – sort of…)
KA7OEI writes: An advantage of Lead-Acid, NiCd, Lithium Ion and some NiMH cell types is that they have quite low internal resistance compared Alkaline cells: Even an aging lead acid battery that is near the end of its useful life may seem to be “OK” based on a load test as its internal resistance can […]
Output voltage control of DC/DC converters
Thomas Fischl writes: Some applications needs to control the output voltage of a dc/dc converter instead using a fixed output voltage. For example battery chargers has to adjust the output voltage to the current battery level. This page shows how to add such a control function to a buck converter circuit. Control output via external […]
ESP8266 troubleshooting guide
Rui Santos has written an article on SP8266 troubleshooting guide: The ESP8266 has a few common issues, specially when you are trying to flash a new firmware or uploading scripts. This is a companion guide to the Home Automation using ESP8266 and Password Protected Web Server eBooks. Here’s a compilation with some of the most […]
Simple Arduino SD-Card GPS/NMEA Datalogger
KF5OBS writes: This article is going to show how to build a minimalistic GPS datalogger. The GPS logger is based on the Arduino platform and stores raw NMEA sentences from pretty much any GPS module to a SD card. More details at KF5OBS blog.