Arduino At Home DIY Electronics

A reader emailed me a little while ago to ask for my help to program an Arduino board as a safety cut out. He was building a cartridge reloading machine that needed a safety cut out in situations where the motor jams. The solution using an Arduino Uno turned out to be remarkably simple. More...

The Arduino Pro-Mini is a tiny microcontroller with similar features to that of the UNO. It has a bootloader for uploading programs but unlike the UNO it doesn't have a USB interface so you need to use a USB to serial adapter to use it.

Why not use an In System Programmer (ISP) instead? You can use a cheap UNO as an ISP and you can then program the bootloader and fuses as well as the application program. Sounds like a win-win to me. More...

Have you ever wondered how they make the parking sensors that you seem to find on all new cars? You know, the ones that start beeping when you are getting close to an object you should be avoiding. The beeping gets faster and faster as you get closer until the beeps all merge into one and... too late you've hit it! More...

Driving an LED from a 5v microcontroller is no problem. Flashing a red, blue, green or yellow LED should be possible even with a microconroller running at 3v but what if you want to drive a white LED that doesn't strart to illuminate until it's voltage gets to about 3.1v?

Worse still what if you are designing a battery operated device and you wanted to squeeze every last second of juice from the battery by allowing the voltage to drop to the minimum the microcontroller will work at? This would be 1.8v in the case of an Arduino chip which is way short of a glowing white LED. The solution is to add a voltage multiplier to the controller output driving the LED. More...

Don't be afraid to use interrupts in your Arduino sketches. Interrupts enable you to do so much more with your Arduino that it's well worth taking the trouble to learn a few simple rules. Almost every project you work with, whether it's a user interface, a clock or you are controlling a robot, your sketches are likely to benefit from some use of the interrupt mechanism. More...

Do you have a 5v FTDI serial adapter and a 3.3v Arduino or Raspberry Pi? You know that you can't plug the adapter directly into the 3.3v microcontroller right but did you know that it's quite possible to build a simple voltage level converter to solve the problem?

I bought a 3.3v Arduino Pro Mini compatible board for a project but I made the mistake of ordering the wrong FTDI serial adapter. I got a 5v unit instead of a 3.3v one but I needed to use it quickly so I used 3 resistors to convert the levels so that I could use FTDI adapter with the 3.3v microcontroller. I thought that you might find this little converter board useful too More...

The Arduino Uno is an inexpensive computer on a board. It has everything that you need to make a smart controller similar to the ones that you might find in any electronic product available nowadays.

If you are looking for a cheap way to start learning how to design embedded microconroller circuits or you need a programmable controller for a project then this could be your simplest and most cost effective solution. Anyone can use one of these More...

Let me show you how servo motors work and what you need to do to drive them. There's a handy library that you can use with Android which makes things very easy called 'Servo'. But what if you need to drive the servo some other way? If that's the case then you will need to know something about how they work.

I will show you how to connect one up and write a very simple Arduino sketch to experiment with. I explain exactly what goes on inside a servomotor and I finish up with a set of oscilloscope traces. If you want to know more about servo motors then read on. More...

How to build a simple but useful strobe based tachometer using an Arduino Uno, an LCD/Keypad shield and a few transistors, LED's and resistors. Short pulses are generated with a simple Arduino sketch and used to drive a bank of LED's. This produces short regular pulses of light which when synchronized with the speed of a fan or motor or other rotating object, makes the moving object appear to be standing still. When this happens the light pulse rate is equal to the RPM of the object. More...

Building on the Arduino Distance Sensor project you can now add motion detection to the features of the device. It detects when objects appear in front of the sensor and because it's ultrasonic it will work in the daylight just as well as it does at night. This can be an advantage over passive infra-red detectors. More...