Arduino based laser pointer to honor Galileo

K.Crankshaw with his partners wanted to build something in Galileo’s memory who made important discoveries in astronomy. They though that the easiest way to learn sky objects is when someone or something points them. So they came up with Arduino based accurate laser pointer which can points its beam directly to wanted objects. Sounds cool. They build built a wooden pan and tilt stepper motor driven mechanism which can point laser to any direction on a top half of sphere of sky. Arduino communicates to python code via serial interface to get desired sky object location then it drives motors to point its position with laser. Why not to scale it up to work with telescope? Continue reading

Anyone can build egg-bot

Probably many of you know original Egg-bot which is great tool to decorate eggs. If you are looking for quality job, don’t hesitate get one. Anyway if you feel it is a bit too pricy or you want to challenge yourself, then follow the instructable written by Nikus, who have built pretty good working clone with Arduino. The bot is built around Arduino with atmega328 which controls couple stepperĀ motors through A4988 based motor drivers. Micro servo moves pen up and down while drawing. Controller PCB was made on home conditions what is pretty rare these days. You can draw the material with Inkscape and then export G-code with extension available. Then with Spherebot_UI send commands to Arduino which in turn starts drawing. This way you can decorate any small round objects with relatively smooth surface. 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

Driving allegro A4988 using arduino

Driving allegro A4988 using arduino

Stepper motors can be used in many handy applications. Their rotation angle and speed are easily controllable within some safe range. But in order to drive them correctly you will need to count pulses as stepper motors is spinning only when it gets step commands. Luca shares his experiment where he explains how to drive allegro A4988 stepper motor using building blocs of hardware including Arduino, LCD keypad shield and Pololu A4988 driver. He wrote software bits that allows him controlling motor speeds from 0 to 70RPM. Using keypad shield buttons he is able to adjust rotating speed and direction while seeing current results on LCD screen including progress bar. Arduino sketch code uses timer1 to calculate timing steps. He uses Timer1 library for easy configuring the timer without digging too deep into of AVR chip itself. Continue reading