This project required 2 separate stepper motors to be exactly synchronised and controlled remotely via a wireless RF remote. The 2 motors had to start and stop at exactly the same time in order for the final product to be acceptable in its application. In addition to this the units required highly accurate resetting and it was therefore necessary to incorporate an absolute positioning encoder into the system.
By using the ZD10 stepper motor controller and developing a simple plugin board to act as the wireless communications interface we were able to keep the cost down for the customer and also develop the project very quickly.
Initially it was thought possible to develop the system using an open loop stepper system. However, on testing it was found that the synchronisation was unsatisfactory. Based on this we employed a simple closed loop system based on an optical switch creating a pulse output for each controller.
This enabled increased accuracy and allowed the controllers to communicate their position to each other via the RF interface.
The closed loop system allowed each motor controller to know its own position. However, when connected via the RF plugin board the two controllers are then able to communicate with each other, verify each other’s position and address any discrepancies in timing or positioning.
Perhaps one of the biggest conclusions from this particular project was the potential projects and applications which can be addressed via the stock range of controllers. The ZD10 is particularly adaptable to a wide range of applications and uses. The flexible design enabled the RF transceiver module to be quickly added to the board with the programmability being key to developing the specific firmware required for this application.
