[SOLVED] TTL UART CP2102 Converter: not in sync

Hi there! I have an Arduino ethernet Rev2: 90-A2-DA-0D-6B-74 and one of this TTL UART CP2102 (link here: http://www.ebay.it/itm/111265789816?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649). To connect the board I've followed this simple pinout (http://arduino.cc/en/Main/ArduinoBoardEthernet):

Arduino Ethernet

"Pin 1 is the pin 1 is the closest to the regular TX / RX pins and the pin 6 is next to the micro SD reader.

  1. GND
  2. Not connected
  3. 5V
  4. RX
  5. TX
  6. Reset"

CP2102

Pin 1 is on upper right corner, looking at the USB connector from the back side:

  1. 3.3V
  2. RST
  3. TXD
  4. RXD
  5. GND
  6. 5V

So, my connection scheme is:

Arduino CP2102 1 5 2 3 6 4 4 5 3 6 2

The problem is the following: whenever I try to program it I have the following error: "arvdue: stk500_getsync(): not in sync: resp=0x00" I've tried to press reset when uploading but it's not helping so far. I've tried both on Windows (8 and 7) and Linux MINT 16. On Windows I've used the driver on the following page: http://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx

I've followed this topic: http://forum.arduino.cc/index.php?topic=138611.0 and I'd like to put a 0.1uF capacitor between DRT and Reset (as suggested by Erni), but I don't have the DRT!

Hope to hear from you soon :)

RST on the CP2102 is Reset into the CP2102. Do not connect. If there is a DTR signal broken out on the module, use that instead. If not, you'll need to manually reset the arduino during the download.

Thank you very much for your answer!

I've tried to reset Arduino during download, but it hasn't worked. How should I do it exaclty? Should I use a particular programmer to do it?

Press Reset after the IDE shows "compiled xxx of 32xxx bytes". Can be easier to find the right time if select File:Preferences and turn on verbose outputs.

The correct timing for doing manual reset to upload depends on which kind of bootloader is inside Arduino. When I'm using Duelmilanove or Diecimilla I press the reset button when the IDE says "uploading" (after compiling). This has worked for me for years.

But you have the Arduino Ethernet, I guess it has the optiboot. Then the timing should be as CrossRoads says.

What you really need to do is to repair the broken USB-serial converter.

I explained how to do it (you need to be able to use a soldering iron) in this post.

Thank you very much for your replies!

Actually I've managed to solder a wire on the DRT, following this guide: http://www.incrediblediy.com/2013/03/modifying-cheap-cp2102-usb-to-uart.html

The problem is that is still not working!

I've also tried to press reset when uploading and I still get the same error, exactly the same!

avrdude: Version 5.11, compiled on Sep  2 2011 at 19:38:36
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2009 Joerg Wunsch

         System wide configuration file is "C:\Program Files (x86)\Arduino\hardware/tools/avr/etc/avrdude.conf"

         Using Port                    : \\.\COM1
         Using Programmer              : arduino
         Overriding Baud Rate          : 115200
avrdude: Send: 0 [30]   [20] 
avrdude: Send: 0 [30]   [20] 
avrdude: Send: 0 [30]   [20] 
avrdude: Recv: 
avrdude: stk500_getsync(): not in sync: resp=0x00

avrdude done.  Thank you.

Don't know what's wrong!

Vortigern: The problem is that is still not working!

You have of course, tried swapping (crossing over) TX and RX - the labelling is often confusing.

Vortigern: I've also tried to press reset when uploading and I still get the same error, exactly the same!

You have to press it - briefly and release it - just as the upload starts. There is some knack involved.

Paul__B:

Vortigern: The problem is that is still not working!

You have of course, tried swapping (crossing over) TX and RX - the labelling is often confusing.

Vortigern: I've also tried to press reset when uploading and I still get the same error, exactly the same!

You have to press it - briefly and release it - just as the upload starts. There is some knack involved.

I've had better luck with pressing and holding down the reset switch and then releasing the button just as the upload starts.

Vortigern:
Hi there!
I have an Arduino ethernet Rev2: 90-A2-DA-0D-6B-74 and one of this TTL UART CP2102 (link here: http://www.ebay.it/itm/111265789816?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649).
To connect the board I’ve followed this simple pinout (http://arduino.cc/en/Main/ArduinoBoardEthernet):

#Arduino Ethernet
"Pin 1 is the pin 1 is the closest to the regular TX / RX pins and the pin 6 is next to the micro SD reader.

  1. GND
  2. Not connected
  3. 5V
  4. RX
  5. TX
  6. Reset"

#CP2102
Pin 1 is on upper right corner, looking at the USB connector from the back side:

  1. 3.3V
  2. RST
  3. TXD
  4. RXD
  5. GND
  6. 5V

So, my connection scheme is:

Arduino CP2102
1 5
2
3 6
4 4
5 3
6 2

The problem is the following: whenever I try to program it I have the following error: “arvdue: stk500_getsync(): not in sync: resp=0x00”
I’ve tried to press reset when uploading but it’s not helping so far.
I’ve tried both on Windows (8 and 7) and Linux MINT 16. On Windows I’ve used the driver on the following page: http://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx

I’ve followed this topic: http://forum.arduino.cc/index.php?topic=138611.0 and I’d like to put a 0.1uF capacitor between DRT and Reset (as suggested by Erni), but I don’t have the DRT!

Hope to hear from you soon :slight_smile:

It looks like you have the TX and RX pins switched. TX on the CP210 needs to go to RX on the Arduino and RX to TX. My CP2102 had the DTR broken out so I can’t help there.

Thank you for your help guys!

The problem, as stated by planecrazy29 and Paul__B, was on the RX and TX! I switched them and everything went well! I apologize for my incompetence!

I also want to mention that I'm using the soldered pin on DRT (http://www.incrediblediy.com/2013/03/modifying-cheap-cp2102-usb-to-uart.html)!

Thank you for your help!