2025-02-19 10:31 PM
I'm new to fiddling with MCUs, so I'm looking for some advice, I'm working on a project for my class and I'm trying to emulate a keyboard using the nucleo-F103rb. I have my code written out, I have a usb cable with D+ Connected to PA12 and D- to PA11, GND to GND and VCC to E5V all within CN5. Despite having all the headers in place, my computer doesn't detect any connection whatsoever. If anyone could suggest anything that may help it'd be really appreciated.
2025-02-20 05:54 AM
Do you have a 1.5 kOhm pullup on USB_DP?
2025-02-20 11:30 AM
2025-02-21 09:33 AM
I currently do not, I'm a little new to this so excuse my lack of knowledge, would any 1.5 kOhm resistor from amazon or whatnot work fine?
2025-02-21 09:35 AM
I have not, albeit I have looked at the ST videos based on "stm32 usb training", ill check this out too as well as trying with a 1.5 kOhm pullup and update this post when I do. Much appreciated.
2025-02-21 09:46 AM
Yes, any resistor should work.
The STM32F1 is very old. Newer families have an integrated pullup that is activated when the USB is used. I'd recommend switching to a newer family if you can.
Introduction to USB hardware and PCB guidelines using STM32 MCUs - Application note
2025-02-21 09:51 AM
Much Appreciated, I'll update this post when I've tried it. Yeah definitely, I originally got the board for learning purposes because I intend to modify a device we have for my course which also has an STM32F1 board albeit I felt it would be best to learn about it first and then tinker with it.
2025-02-22 05:40 AM
Update: I connected a resistor to USB_DP and 3.3V supply and I finally have a connection. Now my issue is, is that it detects it as "unknown USB device".
2025-02-22 07:39 AM
Here's an example that works.