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Revision as of 15:13, 1 January 2016 by Rew (talk | contribs) (programming/protocol)

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The USB stepper allows you to step a small stepper a certain number of steps at regular intervals.

The intended use is for example home-built clocks.


The usb-step has basically two connectors. The USB connector (micro USB), and a 5-pin JST for the stepper motor.

The board has a few other connectors for debugging (for us), for power (GND/3V3/5V between the motor and USB connector), for SPI (in the future we might make it possible to add an SPI display for example), and for selecting the voltage of the powerpin of the SPI connector. These connectors are unpopulated.

The board is 50x25.


The JST power connector is something like 1 - 5V 2 - A+ 3 - B+ 4 - A- 5 - B-


By default the board will step every second, and make a full revolution in 15 minutes.


When you insert the board into your PC, you will get a virtual com port (VCP). Under Windows you should get a device for which "no driver could be found". install XXX this driver, and you will get a virtual com port.

Use your favorite serial-communciation program to connect to the VCP. (I suggest Minicom for Linux users, putty for windows-users).

you'll be presented with a commandline interface. The "help" command lists the available commands.

clock lists or sets the "steps-per-second" setting.

cal lists or sets the crystal calbration.

write writes the current settings to flash.

pat allows setting the activation pattern. For forward use: 4 1 2 4 8, for reverse use "4 8 4 2 1" as the arguments.

step allows setting the time that the motor is activated/stepping speed. Times are in ms.


In the future the interval between each group-of-steps will be configurable, currently fixed at "1s".