First Test

A project log for DIY ST-LINK V2.1

Small ST-Link design that can open VCP and program your STM32's

Emre ÖzkanEmre Özkan 07/06/2020 at 07:380 Comments

The first test was unsuccessful. After the assembly, there was no magic smoke(There is a 22r resistor in the middle of the PCB because I forgot to order them in 0402 packages). But the USB port was not working. Not even "USB Device Not Recognized" error appeared. 

Then I checked the schematic and I realized there was no PullUp resistor in the USB data line. When I add the PullUp resistor, there was a "USB Device Not Recognized" error, which is nice because this error will be gone when we program the MCU with ST-Link firmware.
I did update the schematic file with the correct PullUp resistor.

However, there is still one problem. The programmer stops working after some time. I will search for fixes for this problem, after that will send the new Gerber files to OshPark.