After the microcontroller is connected to the computer via a USB cable, the problem of "unrecognized USB device" appears

反倒是fdsf

After the microcontroller is connected to the computer via a USB cable, the problem of "unrecognized USB device" appears [Copy link]

After the microcontroller is connected to the computer via a USB cable, the problem of "unrecognizable USB device" appears. I wanted to imitate Atom's one-click download circuit and make a minimum system board that is easy to burn. However, after I soldered the circuit and connected it to the computer via a USB2.0 data cable, the computer prompted that the USB device could not be recognized. It is speculated that the problem should be in the one-click download circuit diagram, but this diagram is copied from Atom, so it should be correct. Now I can't even burn the program, let alone debug it, and I have no idea where to start. Could you please help me check if there are any errors in the schematic diagram or PCB? Thank you very much. The figure below is Atom's one-click download circuit for reference.

沁恒USB单片机

Hello, please refer to the latest manual of the official website for the circuit of CH340, which is the circuit shown above. In addition, Qinheng USB microcontrollers are recommended: enhanced 51 core, with USB master and slave, 16-way touch buttons, 16-channel 16-bit ADC, PD fast charging, Type-C video output, 8-way PWM output and other rich resources.

LuJianchang

There is a high possibility that the USB port and CH340 are not soldered properly. Check whether there is false soldering, poor soldering, open circuit, short circuit and other faults. Also, is the CH340 driver installed?

沁恒USB单片机

Please refer to the CH340 manual for the schematic diagram.

反倒是fdsf

LuJianchang posted on 2018-10-26 09:02 It is very likely that the USB port and CH340 are not soldered properly. Check whether there are false soldering, cold soldering, open circuit, short circuit and other faults. Also, check whether the CH340 driver has...

I checked the ch340 soldering and reinstalled the driver, but it still didn't work. My crystal oscillator is 11.0592Mhz. Could it be related to this?

philips_lu

On the contrary, fdsf posted on 2018-10-26 15:57 I checked the ch340 soldering and reinstalled the driver, but it still didn't work. My crystal oscillator uses 11.0592Mhz. Will it have a certain impact with this...

? I haven't done any experiments, so I'm not sure, but it should work normally. You can try to test the voltage of each pin to see if there is anything wrong. For the crystal oscillator, you can use instruments such as voltage, frequency meter, oscilloscope, etc. to check whether it is working. The crystal oscillator working is the premise

反倒是fdsf

philips_lu posted on 2018-10-26 23:22 It will have some impact. I don't know without experimenting, but it should work normally. You can try to test the voltage of each pin to see where it is abnormal. For...

I have used a multimeter to measure that the crystal oscillator is not vibrating. I replaced it with a 12MHz crystal oscillator and solved it. Thank you.