Driving three servos with potentiometers on Arduino

This is really simple setup where you can drive three servo motors by turning potentiometers. It really takes few lines of code and minimal circuit setup, but if you look more deeply at this solution you can find many uses of it. Simply you can build a remotely controlled rig which could do some fancy stuff. This can be a small robot arm which can be further extended by adding magnetic actuator and so on. If you need more degrees of freedom, keep adding more pots and servos. Continue reading

Upgrading old sewing machine with Arduino control

Andrew has an old sewing machine that does great job, but has only couple features like straight and basic zigzag. So he thought it would be fun to incorporate Arduino and servo motor to enhance its functionality. So he ended with CNC sewing machine which can work in several modes. First of all it duplicates previous options so it would work as previously. Then it can sew with one of 10 preset patterns that are stored in Arduino memory. And lastly it can accept new patterns via USB interface. Servo motor is nicely integrated in to sewing machine which simply drives needle horizontal position. Needle bar is equipped with sensor so Arduino could know when its in full-up position. Project is still in development phase so hopefully we will see some clever sewing that include letters and some basic graphics. Continue reading

Analog webserver response meter

If you are running webserver you probably know that one of important performance parameters is response time. In order to keep an eye on server status, Jacob have built a webserver response meter which uses servo driven analog arrow to indicate how fast requests are served. Also there are couple 7 segment led displays where time is indicated in milliseconds and current number of requests. A small 8×8 LED matrix display is used to show graphical info like happy face is everything is all right. Code runs on Arduino which accepts server data via USB interface. Host runs NodeJS application which requests data from API. Then according to response time servo is controlled to display speed gauge. Continue reading

Home built versatile servo tester

Servo motors can be used in many areas like RC modeling, robotics and control devices. They operate by applying PWM signal. By varying duty cycle we can change its rotating shaft angle. If deal with servo motors a lot you probably know that like any other device may be faulty or have flaws. So it is best to check them before installing. You can buy many types of servo testers for cheap, but Jan_Henrik decided to build one. His intent was to make it versatile. Servo tester is built around Attiny45 microcontroller which is programmed in Arduino language. Servos may come with different signal wiring, so he added three jumpers to select proper connector layout. PWM duty cycle is controlled with potentiometer. If you place any other resistive device like LDR, or thermistor instead of potentiometer you can use it for controlling fan speed or open/close vent hole. So this is great device that can be put in an hour. Continue reading

Arduino bot uses stepper motors to drive

Bajdi have build pretty interesting bot platform. To drive the bot he used four small stepper motors that are mounted on servo motors. Servo motors are used to change direction. Such construction looks pretty effective. Bot can change direction instantly by turning wheels while platform stays at same position. It seems that small stepper motors are slow and have low torque. To compensate this he gave more power by attaching 3S LiPo battery. Stepper motors require 16 I/O pins. Plus 4 for servos. To reduce pin usage he used 74HC595 shift register. Instead of using Arduino library Bajdi wrote his own routine that gave him more confidence. And freedom while driving motors through shift registers. Continue reading

PC mouse guided laser pointer

If you are thinking on building a toy sentry gun, following project might be great way to start. Chirag put together pretty cool project – PC mouse controlled laser pointer. It is based on Arduino which controls two servo motors. One takes care of vertical and second of horizontal rotation. Thus laser pointer can cover half globe. To get coordinates he wrote a Python script which reads mouse coordinates and sends to Arduino through serial interface. With Arduino UNO or Leonardo mouse could be connected directly to Arduino. This project can be improved further by adding sensor and firing mechanism to make it real targeting gun. Continue reading