Problem program Arduino Uno via uart

Hello everyone, I know this is not a new topic but now i can't find the solution in my case. My Arduino Uno board is working well via usb port but, i recently i bought a new usb to TTL Ch340, and im try to upload the program via UART. i Connected wire as
Uno CP340
5V 5v
gnd gnd
Rx Tx
Tx Rx

I've choose the right port and Programmer is ARR MKII
cuz CH340 usb is not have RST pin so when i uploading the blink code, I pressed RST button in Uno and Released it. im watting for a time and the error display:
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0xb0
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xb0
Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

The yeallow led is On countinues... Pls help me!!!

miniTalk #3: What's use of DTR pin to program Arduino Pro mini

On the Uno, you can't do the DTR reset trick, because that circuit is already present on the DTR pin of the on-board serial adapter, and the two capacitors will fight eachother, and neither of them will be able to reset the chip.

You need very good timing for uploading with reset button and external serial adapter, because the bootloader is designed to get reset at precisely the right moment by the DTR autoreset circuit, and doesn't wait very long for you to start uploading a program.

Even if you get the timing right, your external serial adapter almost certainly has resistors in series with the TX and RX lines. So do the TX and RX lines between the on-board serial adapter on the Uno and the uno pins. Together these will form a resistor divider. The idle TX line of the on-board serial adapter will be held high, and depending on the relative values of the series resistors on the data lines, the voltage may remain too high when the external serial adapter tries to drive it low for it to be registered as low by the arduino.

In summary, trying to use an external serial adapter on the uno is filled with pitfalls owing to the fact that there is ALREADY A SERIAL ADAPTER ON BOARD.

If you want to program an Arduino with an external serial adapter, use an Arduino Pro Mini, which does not have an on-board serial adapter to fight with the external one.