In this project, I show you my new development which is a high-performance 3-axis stepper motor control board. It is high-performance because it uses the super-fast Teensy 4.0 microcontroller and it also uses a modern TMC429 stepper motor ramp generator controller together with three TMC2209 stepper motor drivers. The board can be controlled via buttons and a joystick, and I also programmed it to be fully controllable by sending commands and parameters via the serial terminal.

The board is originally intended to be used for a 3-axis stage setup, for example, as an X-Y stage and Z focus in a microscope system. But it can be used anywhere where 3 motors need to be moved with high precision. The system has three modes.

• A joystick-controlled mode where the user can control the 3 axes with a 3-axis joystick
• A button-controlled mode where the user can select an axis and move it in the positive or negative direction with buttons
• A USB-controlled mode where the user can send commands and parameters from the computer to control the 3 axes.

The system has 6 limit switches, where each axis has 2 switches. Each switch acts as a stop switch. If they are hit during the movement of the motor, the motor stops and then it parks. Furthermore, each axis has a switch (in my application, it is set to be the left switch) that acts as the reference/home switch. Upon startup, each motor goes to its home position and parks using the left switch of the respective axis.

The board has an extra header pin set for the i2c bus (SDA0 and SCL0). It is useful for adding external switches. Furthermore, all “regular” GPIO pins of the Teensy 4.0 are available on the board, so if other pins are needed, they can be accessed with a regular Dupont wire. Also, there are some extra 3.3 V and ground pins available on the board in case the user wants to power something.

Remarks:

Due to the uniqueness of the board, I only prepared the usual interactive BOM for this board. This is because the user can freely vary many components, especially the terminals. For example, the controls such as the buttons, joystick and switches can be directly connected to the board by soldering their cables in the PCB. In that case, all the jumper headers are unnecessary. The same applies to the microcontroller and other modules, however, it might be a good idea to mount them as I did (removable) in case they fail for some reason and they need to be replaced. Also, some parts, especially the Teensy 4.0 microcontroller and the TMC429 ramp generator cannot be sourced from AliExpress or similar sites. They have to be purchased from Mouser, Farnell or similar distributors. On the other hand, the MP2315 voltage regulator is only available on websites such as Amazon or AliExpress.

Don't forget that the circuit needs a "modification" in order to provide 3.3 V. The trace under the potentiometer (ADJ) has to be cut and the solder tabs at the silkscreen that says 3.3V must be shorted together. I also describe this in my video.

If you want a "more official" product, then the SparkFun BabyBuck Regulator can also work. Just pay attention to the polarity of the pins, because the VIN and VOUT are the opposite of the MP2315.

https://www.sparkfun.com/products/18357

[2024-05-27 UPDATE]

I finalized my motorized microscope whose stage and Z-axis are driven by the circuit shared on this page.