On the next version of the app which will be fully automatic, this will tell the tablet that the component has been picked and the selector can now move to the next required component and also rotate the picker needle if required. On the back of the main pick and place, the machine is a dual break beam sensor Motion Direction Controller (code and circuit on GitHub) which sends back a command via interrupts on the Arduino to the Android app. All component pickers are then referenced by an array in the Arduino code for the stepper position. The X-axis then slowly moves to the side until the second IR break beam sensor is triggered which then sets the X-axis to zero point. When a reset command is received or upon start up the Y axis retracts up until an IR break beam sensor is broken which then sets the Y axis to zero point. The Android app sends a single character to the control board to either select a component feeder, turn the picker needle or perform a reset of the system. The motors came from a scrapped vinyl cutter which was given to me a few years ago.

The component picker assembly uses a pair of NEMA 17 motors to drive the X and Y axis driven via MD430 stepper motor drives sourced from eBay.

The system communicates using serial commands using Bluetooth between the Android tablet and Arduino Mega and this uses the AccelStepper library to allow much smoother control of the stepper motors. Following the Arduino pick and place update blog post video and Automatic component feeders post we have now completed the first version of the Android tablet control software which uses Bluetooth to communicate with an Arduino Mega to control an X and Y axis on the component selector and also to a second Arduino Mini board which controls the pick and place needle rotation.

Diptrace arduino