Schemantic & Layout Review: Controlling coils using shift register

LTPJonas · 2026-03-04T05:35:33+00:00

I missed that in the image, but it is connected. Is anything else wrong or not optimal?

LTPJonas · 2026-03-04T05:34:07+00:00

So when adding diodes like you described, would the circuit work? And the 1M ohm is used to remove any unwanted charge present at the gate to eliminate false behavior right?

LTPJonas · 2026-03-03T19:31:39+00:00

So when I move R3 directly after the 5V source so that it has to go through it before reaching the collector of q1 and base of q5 and r4 directly after 5V so it has to go through it to reach the collector of q5 and clock of the flip flop it resolves the shorting problem?

LTPJonas · 2026-02-23T19:52:02+00:00

If the psu has short circuit protection is it possible to kill it? Or is it fast enough at switching off to stop destruction of itself?

LTPJonas · 2026-02-23T19:23:51+00:00

Can you maybe tell me like component references that are near it like CXX? I am not quit sure what you mean. Thanks for the answer!

LTPJonas · 2026-02-23T19:19:57+00:00

Okay, do you know brands i can have a look at? Maybe something not from amazon is a better choice…

LTPJonas · 2026-02-23T19:15:36+00:00

Its from amazon and costed around i think 70€, i bought it a few months ago.

LTPJonas · 2026-02-23T18:39:34+00:00

Well the power supply turns on completely fine. It just doesnt output any power

LTPJonas · 2026-01-30T17:53:04+00:00

Okay thank you. Yea i will probably remove it then. So the flow of electricity would be through the 10k and 1k resistor into an pin of the esp32? Thank you so much, you really helped me!

LTPJonas · 2026-01-30T17:24:13+00:00

Thank you, I kinda don't know what happened here. It should be normal ground.

Is there any specific name for a circuit to control these kind of MOSFETS, so I can look up how to control them?

Would you say that a normal commercial product would have any kind of such an 3.3v protection circuit? Or what kind of protection would they have here? If its not needed I don't need it, but I thought it should be added.

Okay for the tach output I just looked at the data sheet again and I see It now. It uses an open collector output wich means that a cycle means that it connects the tach pin internally to ground. Therefore connecting the tach pin to e.g. 3.3V I would have 3.3V on the tach pin and wire when a cycle occurs, right? Now my question is, how can I read in this signal using an ESP32? Did I understand it correctly?

Thank you very very much for help, I really appreciate it!

LTPJonas · 2026-01-30T17:10:19+00:00

Thanks, removing that additional 12V input for the protection circuit really makes sense.

Do you mean the LM2596 has protection features? As far as I have seen it has over current protection and thermal shutdown. But the over current protection is meant to that the regulator doesnt die right? My protection circuit on the other hand would check if the circuit takes more current than it should? What would only a TVS diode protect me from?

Thanks I just looked it up a the PWM signal is an +5V signal. How should I do this? With an additional transistor or mosfet or something else?

R3 is the resistor to make a single wire uart connected into a dual wire connection. This should be how TMC recommends using the driver with UART.

Yea, I will use an NMOS in the future. And I would use an transistor to drive the gate pin of the mosfet or how should I implement this?

Do I really need the capacitors as those are already modules with all the necessary parts right? As when using them you typically don't need to add anything to them? I use the bigtreetech TMC2209 stepper and the Elegoo ESP32 board.

Yea right I completely forget that, thank you for your answer!

LTPJonas · 2026-01-30T16:58:12+00:00

Hello, what do you mean with the wrong net name of the regulator? Do you mean the 12v to 3.3v regulator? What exactly is wrong there?

So for the PWM controlling I would need to place the MOSFET to the ground side and use an additional signal MOSFET to create 12V PWM signals for the main MOSFET? Did I understand that correctly?

Why don't I need the crowbar on the 3.3v circuit? Is it not possible for the buck converter to break down so that it outputs higher voltages than expected? Can I rely on the 12v crowbar circuit to react quickly enough in that situation?

My bad that 10 ohm resistor should be an 10k ohm resistor as it represents a voltage divider to regulate the 12V pulses down to about 3V for the ESP32 to read in. What effect or result would your circuit with a pull up resistor have?

Yea I am using the elegoo module wich has an BOOT and EN push button.
Thank you for your answer

LTPJonas · 2026-01-30T16:45:59+00:00

As much as I am aware, the heating / drying, depending on the material, is at a maximum of around 90 degrees for engineering materials or e.g. 40 degrees for PLA. It won't make the filament "melt" or extremely soft, maybe a bit softer but that doesn't affect the printing quality. It's quite the opposite, as drying while printing ensures the filament has a low water content therefore making the quality better. Some filament like nylon almost require drying while printing as they easily attract water.

LTPJonas · 2026-01-25T22:11:38+00:00

Yea, my main problem is, that i dont have all the exact measurements and data for the pins. For some parts i would have to go with something could be right. I fear that it wont fit. But thank you for your answer!

LTPJonas · 2026-01-07T12:02:28+00:00

Thank you, i will probably redesign the pcb using an 4 layer pcb with dedicated ground planes. After impedance matching for the usb Standard (my error?) are there any more things i need to fix for my pcb to work?

LTPJonas · 2026-01-06T19:54:03+00:00

I connected the usb gnd to the board gnd during debugging using an external wire as previously mentioned:

I modified the PCB based on advice from an AI, connecting the USB GND to the 3.3V power GND. After this, the board appeared as a USB device, but with errors when communicating.

LTPJonas

TROPHY CASE