Aug 262017
 

Hello everyone from Day 1 of Hurricane Harvey here in Austin Texas. Wild windy and wet. Just want to mention plans are being made to cover a monitor repair video and a How-To on using the 74HC595 shift register. I love this chip! Be well!

Feb 282017
 

Volthaus Bluetooth Controller Android App

My second Instructable on remote control using Arduino, Bluetooth, and a relay. The first Instructable in this series was designed using the serial communication software PuTTY for turning off and on the remote device from your computer. This one will be quite similar in the setup of the project but we will be using the Volthaus Lab Bluetooth Controller Android phone app for control. The Bluetooth Controller App was designed using the MIT App Inventor and the source code is available below so you can import it into your own MIT App Inventor account console to adapt it to your needs if you wish to extend its capabilities, or just study how it works.

Check it out at:

https://www.instructables.com/id/Remote-Control-Bluetooth-Arduino-Android/

QUICK LINK-All project files here

Jan 132017
 

Using remote control for projects is always fun and gives your project that pro touch. One area of much debate is antenna design and use. I found this article that really does a great job of explaining the design and use of antennas with 433MHz modules. I found this at HOPERF. They make a wide variety of RF products.

Click here to view the PDF.

 

Jul 172016
 

 

Working with Level Shifterspresents400

Level shifters are a wonderful and very affordable solution when you have a situation where you have to interface a 3.3VDC and a 5VDC device. They are also called voltage shifters and they come in uni-direction versions where the signal only goes one way, bi-directional where signal goes both ways, direction controlled level shifters with a dedicated directional pin, logic level shifters that put logic functionality and voltage translation into a single design, and finally application specific level shifters .You will also find them in a variety of multi-channel types as well as bit rates. In this article we’ll cover the 5VDC/3.3VDC bi-directional 2 and 4 channel types available on Ebay for a very low cost and how to use them in your ingenious projects.

Step 1: Two channel level shifter
2 Channel Version

 

This was my first level shifter. I bought it from a seller on Ebay. When i bought I had not yet worked with level shifting so I did not notice the module was not marked to indicate which side was LV (low voltage) or HV (high voltage). Simply put you supply 5VDC and GND (ground) to one side of the module and 3.3VDC and GND to the other side. The first time i used it I was using a 3.3VDC ESP8266 to wirelessly control a 5 VDC servo. Without the shifter the ESP8266 would not boot up. Once I had the shifter in place it performed perfectly.

The markings that are on the module are:prefaced with an “A” on one side and “B” on the other.

  • AVCC (I soon figured out this was the 5VDC input)
  • ASCL – This seems to indicate the module is I2C compatible.
  • ASDA – In an I2C situation this would seem to be the SDA data signal connection
  • AGND – This pin goes to the ground bus

In this example I’m interfacing a 3.3VDC HC-06 bluetooth module with a 5VDC Arduino Pro Mini to turn on and off an LED using Putty on a BT equipped laptop.

Step 2: 3.3VDC HC-06 Bluetooth – 5VDC Arduino Pro Mini

LED Control Circuit

I also bought some 4 channel shifters and they are marked HV and LV which tells me which side should be connected to the 5VDC power and which gets the 3.3VDC power. They are also marked TX and RX but I disregarded that in this setup and I am having no problems TXing on the RXing channel. I’ve breadboarded a 3.3VDC HC-06 Bluetooth with a 5VDC Arduino Pro Mini. using I’m using PuTTY ( a free SSH and telnet client for Windows) on a bluetooth eqipped laptop to control the Arduino to turn on and off the LED. You can get a free copy of PuTTY at http://www.putty.org/

The Arduino Bluetooth LED control sketch is avalable @ http://volthauslab.com/sketchs/Bluetooth/bluetoothLEDcontrol.ino