Arduino Forum

Using Arduino => Project Guidance => Topic started by: msev on Apr 15, 2012, 11:01 pm

Title: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 15, 2012, 11:01 pm
Hi there,
like the title of the thread says, I'm interested if there is a tutorial available that explains how to use a CP2102 USB from ebay and uploading a sketch to an Atmega...And if it works with the latest arduino environment,...and also where to find relevant drivers for Windows Vista.

Regards,

Edit: maybe I should put this topic in Device hacking? please move if you think so.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: cmiyc on Apr 15, 2012, 11:02 pm
Download the drivers from Silicon Labs. Connect tx to RX and vice versa.

It will show up as a virtual com port just like the FTDI chip.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 15, 2012, 11:03 pm
But I've read that you have to modify it in someway to make the auto-reset feature possible? Do you have pics of that mod?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: cmiyc on Apr 15, 2012, 11:06 pm
http://www.google.com/search?q=arduino+cp2102
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 15, 2012, 11:10 pm
Yeah I've already found the link but I'm a bit concerned about the commentarys of people that they didn't get it to work..hope they are just incompetent :)

There seems to be a few different ways to go about it...Which one would you recommend?

This one: http://www.ebay.com/itm/USB-To-TTL-COM-Converter-Module-buildin-in-CP2102-NEW-/251039882204?pt=LH_DefaultDomain_0&hash=item3a73249bdc

That one in the ebay link looks a bit different than the one the guys are hacking...Does this one also require hacking?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: RandallR on Apr 16, 2012, 08:54 pm
The problem that I found is that the "Reset" pin on the board is not one you can use to reset your Aquino and start you download.  It is an input to the CP2102 to reset the converter chip.

The board I got off eBay had an exposed DTR.  You need a Capacitor between this 'pin' and reset (pin 1) on the Atmel chip.

I attached a couple photos of a board like mine.  I got it to work without too much difficulty.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: retrolefty on Apr 16, 2012, 09:17 pm
Quote
That one in the ebay link looks a bit different than the one the guys are hacking...Does this one also require hacking?

Yes, but it may be very difficult to hack as I don't see a DTR signal pad to attach to. The DTR signal is avalibe on the CP2101 chip, but it's very difficult to solder anything to those small spaced chip pins. Doesn't mean it can't be used but you may not be able to get it to utilize the auto-reset function and will have to use a well timed manual push button reset on the arduino board prior/during uploading.

Lefty
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: RandallR on Apr 16, 2012, 11:23 pm
You may need to spend another $3 and get one with a DTR solder point.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 17, 2012, 10:44 am
I didn't yet ordered anything..so I'll order that black one that looks like the one you guys are hacking..made my decision easier, thanks!
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Apr 17, 2012, 01:55 pm
As retro mentions.. a simple, timed button press (reset button) will eliminate the need for any DTR/RESET pad on the FTDI cable end..

I have done it a million times on standalone and breadboard projects...  (a couple of custom boards, that did NOT have a reset button.. I just used my real Arduino as a passive/pass-through device to upload sketches...by removing the Atmega chip in my true Arduino)


this thread may help:

http://arduino.cc/forum/index.php/topic,5453.msg41846.html#msg41846
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 24, 2012, 07:38 pm

The problem that I found is that the "Reset" pin on the board is not one you can use to reset your Aquino and start you download.  It is an input to the CP2102 to reset the converter chip.

The board I got off eBay had an exposed DTR.  You need a Capacitor between this 'pin' and reset (pin 1) on the Atmel chip.

I attached a couple photos of a board like mine.  I got it to work without too much difficulty.



Why do you need the cap, doesn't the arduino pro mini for example already have a cap onboard?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Apr 24, 2012, 07:58 pm
When the arduino has an onboard cap in series from DTR pin to the chip's reset, then a cap is not needed on the CP2102 module.
Adding one results in series capacitance of (C1*C2)/(C1+C5), or 0.05uF with two 0.1uF caps. DTR generated reset may or may not be enough to properoly reset the ATMega.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: RandallR on Apr 24, 2012, 08:23 pm
When I was doing my testing, I was breadboarding the bare chip with crystal, caps, and resistor.  I didn't get past the blinking LED but I will.

I have not looked too closely at the Pro Mini since for a couple dollars more you can get a Nano with a USB to serial built on the board.  It also breadboard quite nicely.  I prefer the Nano to the Uno or Duemilanove because it fits so well on a small breadboard.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 24, 2012, 08:26 pm
Thank you very much!
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Apr 24, 2012, 08:39 pm
I built 15 promini's into fencing club scoring machines. Didn't need USB interface, so I went with the less expensive pro-mini'.
And when I ran out (due to damaging a couple during debug) I started wiring up my own promini equivalent instead. Have not purchased a real arduino since, just made my own clone versions in multiple styles & quantities.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 24, 2012, 09:51 pm
Do you make them with dip atmegas?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Apr 24, 2012, 09:59 pm
what are you looking for? standalone boards?

but in DIP style?

maybe Anatools.com will help, and his Anarduino kit:

http://www.anatools.com/anarduino/

http://www.anatools.com/anarduino/inst.jsp

I found him great to deal with and very nice.

I used a few of these...they are great and are assembled in like 5 minutes.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Apr 24, 2012, 10:35 pm
@msev - yes.
Also DIP ATMega1284's. Extra IO (32 total), dual hardware serial port.

You can see some of my designs at the link in my signature. Gotta find my FTP password so I can upload some more pic's.

Or here for a minimal component '328:
http://store.nkcelectronics.com/arduino-runtime-board-rev-b.html
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 24, 2012, 11:05 pm
I'm looking for a design with the dip package that would ideally have such a pinout for programming pins that it would be directly plug-in friendly for the modified cp2102. Probably I'll have to modify some .brd file of an exsisting  minimal arduino project.. It would be nice if there was a topic, a collection of all minimal arduino projects together :D
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: Brad Burleson on Apr 25, 2012, 01:11 am

When the arduino has an onboard cap in series from DTR pin to the chip's reset, then a cap is not needed on the CP2102 module.


Thanks for that - I'd been wondering why I'd seen the 0.1uF cap added to the board that RandallR pictured thinking that it shouldn't be needed if the 'arduino' has it's own 0.1uF cap on the reset line.

I guess the idea was to avoid having an extra cap on each clone you build?  Too late for me, I always do that.

I'm posting just to confirm for the OP that I bought a pair of the same boards (or at least appear to be the same) that RandallR pictured from dealextreme and the "fix" was as simple as cutting the trace that goes to the RST pin and running a small wire from DTR.  No 0.1uF cap needed if your target board already has it.

I also had to swap the TX/RX lines between the CP2102 and the target board (I've seen some boards where this wasn't needed).

Hope this helps,

Brad.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 25, 2012, 09:31 am
Did you swap them because of the pinout on your arduino, or because the board was mislabeled (that rx was labelled as tx?)?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: Brad Burleson on Apr 25, 2012, 07:32 pm

Did you swap them because of the pinout on your arduino, or because the board was mislabeled (that rx was labelled as tx?)?


My Arduino board uses the standard FTDI pinout if that helps (I only bought the CP2102's to test).  I believe this board actually has RX/TX marked correctly since with my other TTL/USB adapter also crosses TX/RX.

FWIW,

Brad.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Apr 25, 2012, 07:39 pm
its common form what I have seen..

some mark it as to what it GOES to.. an some mark it as what it IS..

once of the first things I try to swap when an FTDI sketch upload fails..

what/where are these boards you are getting??  (that has the DTR pin broke out)

my cheapie cables only ave 4 lines (5 if you count the 3.3v pad)  5v+, GND, RX, TX..

I hve to manually hit the reset button to upload sketches.. not a problem.. but going forward.. some projects wont have a reset button at all.

Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: retrolefty on Apr 25, 2012, 08:58 pm
Quote
what/where are these boards you are getting??  (that has the DTR pin broke out)


Here are the ones I bought, can't beat the price: 
http://www.ebay.com/itm/370532286388?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Lefty
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Apr 25, 2012, 09:17 pm
you dont have to use the 6-pin header do you?

I mean treat this like any other FTDI cable..yes?

as long as I run 5v+, GND, RX, TX to my chip.. Im good.. I can then use/tap the DTR pad from the bottom of the board to use on the DTR of the circuit Im uploading my sketch to....right?

a shame it was brought out on top like the other pins.

also is there a driver for it?


thanks

Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Apr 25, 2012, 10:16 pm
@msev,
a board like you describe is easy to make.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: Brad Burleson on Apr 25, 2012, 10:32 pm

you dont have to use the 6-pin header do you?


Nope. You can wire it up any way you choose.  I do use 6pin headers simply to keep with the standard FTDI pinout.

Note the included (very short) cable actually only has 5pins (you can see that in the picture that Lefty posted).

Quote

I mean treat this like any other FTDI cable..yes?


Sure, just get a couple of the 6pin female crimp housings (such as http://www.pololu.com/catalog/product/1905 (http://www.pololu.com/catalog/product/1905)), remove the single pin plastic housing on each pin, and insert the pins in the correct order.  Or use whatever size header you want, as long as it matches your board.

I'd suggest testing the pinout first just in case :-)

Quote

as long as I run 5v+, GND, RX, TX to my chip.. Im good.. I can then use/tap the DTR pad from the bottom of the board to use on the DTR of the circuit Im uploading my sketch to....right?


You don't really need to pass 5v, but you've got the idea.  I was going to post a picture of a modified board but there isn't much to show - simply a cut trace and a jumper wire.  Takes 2 minutes and seems to work great.

Quote

also is there a driver for it?


Yup.  I think there is a link earlier in this thread.  If not, you can find the driver here http://www.kerrywong.com/2010/07/16/an-arduino-compatible-using-cp2102/ (http://www.kerrywong.com/2010/07/16/an-arduino-compatible-using-cp2102/)

Hope this helps,

Brad.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Apr 25, 2012, 10:49 pm
thanks for the reply..

even found it a buck cheaper on ebay too:

http://www.ebay.com/itm/130683943875?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649


thanks!
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 25, 2012, 10:56 pm

@msev,
a board like you describe is easy to make.


Are you willing to design it for me since you have a lot of experience (in Eagle)? With Dip atmega328.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Apr 26, 2012, 05:34 am
Sure - which parts do you want to keep, and how do want the connector?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on Apr 26, 2012, 10:10 am
Thank you very much, you are really kind! it would take ages for me to draw all the connections...I do quite well for a beginner in the schematic editor, but in the board editor I get into trouble :)..

Well I'd like it to be single sided (I think I've already mentioned that :D) and with a dip package atmega and other parts also normal size (let say 3mm leds) not smd size ..

And I'd like the optional parts also (I'm not sure about that pwr led, it just indicates the arduino is being powered right?) and do I need the reset switch, if I have autoreset? I'd like the layout for the programming pins to be as similar as they can be with the modified programmer we are talking about http://www.ebay.com/itm/USB-2-0-UART-TTL-6PIN-Module-Serial-Converter-CP2102-/370532286388?pt=PCC_Drives_Storage_Internal&hash=item564571ffb4#ht_2817wt_1110 ...
I guess I want a female connector if cp2102 has male pins.
I don't need ICSP.

Thats about it I guess :)

Also maybe I'd like a led on D13 so I can diagnose if the arduino is properly working with blink sketch (or which pin is it, I know I have a led that blinks on my nano if I upload the sketch on it, its permanently on the board).

Oh another thing, I'd like it to be drawn in Eagle :).

I have another question about the bootloader,..I shouldn't buy atmega with optiboot (or uno bootloader) right, but instead with duemilanove bootloader right?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: retrolefty on Apr 26, 2012, 09:26 pm
Also maybe I'd like a led on D13 so I can diagnose if the arduino is properly working with blink sketch (or which pin is it, I know I have a led that blinks on my nano if I upload the sketch on it, its permanently on the board).

Physical chip pin 19 is the arduino digital pin 13. Just wire a resistor and led in series from that pin to ground, with the led cathode lead wired to ground. A 1K resistor is used in the standard arduino board.

Lefty


Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on May 12, 2012, 09:56 am

Sure - which parts do you want to keep, and how do want the connector?


So you won't be designing it  =( :)
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on May 12, 2012, 03:11 pm
??
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on May 13, 2012, 10:40 am
Already designed - just needs a little tweaking.
Unfortunately only so many hours in a day, and I don't always get back to a thread I might be interested in (right away).
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on May 13, 2012, 10:59 pm
I assume you can handle naming of pins on the board if I post the files?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on May 13, 2012, 11:52 pm
Yep that won't be a problem...I see its double sided right?  :), I'll have to learn the correct technique to line all the lines right  :)..
The board in your previous post isn't the same like in your last post right?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on May 14, 2012, 12:28 am
Yes, double sided.
I let eagle auto-route it. It does okay if you  have good parts placement to begin with.
The design is almost the same, added a couple of caps to the +5 line, diode in parallel with the reset pullup resistor, the 3mm LED and current limit resistor, and put all the pins in one row to be breadboard friendly (assuming one installs right angle male header there).
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: msev on May 14, 2012, 12:55 pm
Btw would you try and autoroute a single sided version too?
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: RandallR on May 14, 2012, 03:12 pm
Is anyone planning on sending this to a board house to have it fabricated? 

I like the breadboard friendly nature.  I currently use Nanos but I might like to try one of these boards.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on May 15, 2012, 01:37 am
Several folks have asked - here are the eagle files for the single-sided board I posted earlier.
Remember,  I had not updated all the pin numbers, that was "left as an excercise for the reader".

Others had asked about a single-sided version. I'll post one of those in the next message.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on May 15, 2012, 01:40 am
Single sided board. Haven't tried to make the pins all along 1 edge.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: gerg on May 15, 2012, 02:12 pm
I bought four of these a couple of months back at $2.84 delivered. They are still available. All have registered on the USB bus and two have been tested on all pins via volt meter (and an uno driving inputs) and python serial. So as far as I know, they are good-n-cheap. It has all of the signals broken out on three of the edges. I'm very happy with these.

http://www.ebay.com/itm/350499583299?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3DSee-All-Categories%26_from%3DR40%26_nkw%3D350499583299%26_rdc%3D1

I soldered headers to one of them and will do the same with at least a second. I also straightened and shortened the 90-degree headers on the end which came with it. ts now ready to plug into a set of complimentary headers on the bottom of my my arduino project board.

Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on May 22, 2012, 06:46 am
Got my two as well..

$2.95 shipped...

took a few weeks of course..

but came, and look fine.

work fine too (after you install drivers of course)..

I mo'd mine as well....

I cut off the last header.. and and attached 'two',, one in the same place.. and one that hangs over the side a bit.. then I jumpered this to the DTR pin.

I probably didnt need to keep the RESET pin..  but whatever..

(http://dmstudios.net/misc/CP2102_USB_UART_mod-001_small.jpg)

tested and programmed a custom Arduino board with it.. for $3.00 I cant complain!

Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: RandallR on Jun 05, 2012, 02:48 am
Here is my hack for the CP2102.
1) Cut the reset trace.  This is the input to reset the CP2102.
2) Soldier a .1uF  cap from the DTR output to the Reset Pin

This now works great.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Jun 05, 2012, 04:56 am
awesome.. its "clean".. so to speak.


is the cap even needed if your circuit has one already? (ie: an Arduino compatible pcb with DTR breakout already...etc).. then only a 'jumper' yes?

nice one!.. (Im going to something similar on my other one now)

thanks!  :)
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: RandallR on Jun 05, 2012, 05:17 am
I use mine for breadboarding so I always need the cap.  I've tested it of course and it works well for me.  I may place a dot of hot glue under the cap the next time I have my hot glue gun out.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: Brad Burleson on Jun 05, 2012, 05:56 am

is the cap even needed if your circuit has one already? (ie: an Arduino compatible pcb with DTR breakout already...etc).. then only a 'jumper' yes?


It's actually mention earlier in this thread by CrossRoads that if you add a cap on the CP2102 as well as have one on the board the results may be undesirable. 

So no, it's not needed and yes, just a jumper.

Brad
KF7FER
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Jun 05, 2012, 06:07 am
Looks beautiful!
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: 61bertbert61 on Feb 03, 2013, 05:01 pm

Quote
That one in the ebay link looks a bit different than the one the guys are hacking...Does this one also require hacking?

Yes, but it may be very difficult to hack as I don't see a DTR signal pad to attach to. The DTR signal is avalibe on the CP2101 chip, but it's very difficult to solder anything to those small spaced chip pins. Doesn't mean it can't be used but you may not be able to get it to utilize the auto-reset function and will have to use a well timed manual push button reset on the arduino board prior/during uploading.

Lefty


first post here, just to mention i just succeeded to upload sketch using a cp2101 and a rbbb after having read about the 'well timed manual reset'

Thanks!

61bert
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: dannable on Feb 03, 2013, 08:06 pm
My latest CP2102 based device from eBay has arrived, and whilst the image looked like the one in this article it was of a slightly different design which means this mod cannot be effected.

So if you are buying one it might be worth checking with the seller that it is exactly as illustrated.

Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Feb 04, 2013, 12:21 am
How about some more info?

like a link to the ebay auction you DID purchase from?  (and ebay seller name)

and also maybe a pic of the hardware/device you DID get?

if I was bait-n-switched... I would have gotten a refund.

Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: dannable on Feb 04, 2013, 12:41 am
Well, this is what I thought I'd bought..

http://www.ebay.co.uk/itm/110760144325?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 (http://www.ebay.co.uk/itm/110760144325?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649)

But this is what arrived (taken at random, just to illustrate)

http://www.ebay.co.uk/itm/USB-2-0-to-TTL-UART-6PIN-CP2102-Module-Serial-Converter-K-/130772178661?pt=UK_Computing_Parallel_Serial_PS_2&hash=item1e72a116e5 (http://www.ebay.co.uk/itm/USB-2-0-to-TTL-UART-6PIN-CP2102-Module-Serial-Converter-K-/130772178661?pt=UK_Computing_Parallel_Serial_PS_2&hash=item1e72a116e5)

But it does "what it says on the tin", so no grounds to return it. Plus it would probably cost more in carriage costs than it cost to start with.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Feb 04, 2013, 05:46 am
Yep, you got screwed.
Next purchase, try the ask question option to confirm you're getting the one with pads.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: RandallR on Mar 30, 2013, 02:15 pm

Well, this is what I thought I'd bought..

http://www.ebay.co.uk/itm/110760144325?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 (http://www.ebay.co.uk/itm/110760144325?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649)

But this is what arrived (taken at random, just to illustrate)

http://www.ebay.co.uk/itm/USB-2-0-to-TTL-UART-6PIN-CP2102-Module-Serial-Converter-K-/130772178661?pt=UK_Computing_Parallel_Serial_PS_2&hash=item1e72a116e5 (http://www.ebay.co.uk/itm/USB-2-0-to-TTL-UART-6PIN-CP2102-Module-Serial-Converter-K-/130772178661?pt=UK_Computing_Parallel_Serial_PS_2&hash=item1e72a116e5)

But it does "what it says on the tin", so no grounds to return it. Plus it would probably cost more in carriage costs than it cost to start with.


This happened to me one time.  I simply wrote the seller with a picture of what I received, and pointed out that the picture differed from what was advertised.  The seller posted a replacement of the right type.

eBay sellers usually dislike negative feedback.  If what they sent does not match what was advertised then that is cause for negative feedback.

On the other hand if you ordered the wrong one because you did not inspect the photos, or there where no photos to inspect, then the fault is yours.  On the bright side, you should not have spent more that a morning cup of coffee on the board.

I know that most people complain about the quality of parts from China, and they are right.  However, for the savings, I am usually willing to put up with the lower quality to save some money.  I do this as a hobby, I enjoy playing with these things.  If I where making a production quality product, with my name on it, I would source my part with greater care.  But I'm not, and I don't.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: kanurys on Oct 11, 2013, 04:33 am

Got my two as well..

$2.95 shipped...

took a few weeks of course..

but came, and look fine.

work fine too (after you install drivers of course)..

I mo'd mine as well....

I cut off the last header.. and and attached 'two',, one in the same place.. and one that hangs over the side a bit.. then I jumpered this to the DTR pin.

I probably didnt need to keep the RESET pin..  but whatever..

(http://dmstudios.net/misc/CP2102_USB_UART_mod-001_small.jpg)

tested and programmed a custom Arduino board with it.. for $3.00 I cant complain!




What drivers did you end up using for this device? I'm about to buy one from ebay but I want to make sure I can support it for windows 7. -thanks
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: CrossRoads on Oct 11, 2013, 05:56 am
The Bate units often come with a mini CD that have the CP2102 driver.
Or Win7 might have it already, or can do an autosearch & find it.

I just cut the reset trace and added the wire from the DTR hole to the pin.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: xl97 on Oct 11, 2013, 06:14 am
I tried to look see if I still had the file..

I found a couple, 9maybe searching fro these names will give you more info)

CP210x_VCP_Win_XP_S2K3_Vista_7.exe
an335sw.zip

I believe it to be the top one... (but its been a while)  :)
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: kanurys on Oct 11, 2013, 07:29 am
10-4, thanks guys.
Title: Re: Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega
Post by: Naveen_prasath on Oct 05, 2015, 12:48 pm
hello everyone,
i just bought the cp2102 module and i have installed all drivers for it. i want to upload sketches through cp2102 to arduino uno
i made connections as

cp2102                   arduino

DTR                       RESET
VCC                       5V
TXD                       RX
RXD                       TX
GND                       GND

arduino IDE says "done uploading" but i dont see any changes in my uno. i made blink sketch but it didn't show any changes
please help