Schematic USB connector PCB

I made this custom board that contains a complete arduino nano on it. I soldered every component with extreme care and already check all the connections and they all go according to the designed schematics. But i seem to have a problem with the serial communication between the computer and the board. Im almost certain the problem has to do with my CH340C IC, but i have already replaced it 3 times.

This is the problem: Here we can see the error that im having

I know the arduino is working because i burned the bootloader and uploaded some example sketches to it trough the ICSP pins.

So maybe i have a design flaw? If I do please let me know.

  • \$\begingroup\$ Do you have: * Decoupling capacitors on the CH340C? * Good differential pair routing for D+ and D- (maybe it's not so important for low speed USB though)? * Have you double checked the connections on the micro-USB connector? \$\endgroup\$ – user253751 Aug 19 '18 at 23:32
  • \$\begingroup\$ Sometimes the connections on the USB are numbered in reverse. Are you getting +5 on VUSB? See the original Arduino schematic. \$\endgroup\$ – Spehro Pefhany Aug 19 '18 at 23:59
  • \$\begingroup\$ The IC is receiving solid 5V from a on board boost converter. I've check the connections on the USB connector and everything just as described on the schematics. I also use the USB power to charge a battery, and the battery is charging just fine. \$\endgroup\$ – carloslockward Aug 20 '18 at 0:08
  • \$\begingroup\$ I have a couple capacitor in the output of the boost converter. 4.7uf and 22uf. The routing on D+ and D- is nothing special but at least the PC should recognize the IC. \$\endgroup\$ – carloslockward Aug 20 '18 at 0:14
  • \$\begingroup\$ So do you have a capacitor each on the 5V and 3.3V lines of the CH340C, nearby to the IC? Actually the datasheet (translated from Chinese) recommends that when using 5V power, connect the 3.3V pin to a 0.01uF capacitor and do not connect it to power. Apparently it has some internal regulator. \$\endgroup\$ – user253751 Aug 20 '18 at 1:06

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