Tutorial for hacking a CP2102 USB from ebay and uploading a sketch to an Atmega

I assume you can handle naming of pins on the board if I post the files?

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?

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).

Btw would you try and autoroute a single sided version too?

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.

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.

sidemount_duemilanove_DIP_rev_noreset_switch.sch (913 KB)

sidemount_duemilanove_DIP_rev_noreset_switch.brd (89.3 KB)

Single sided board. Haven't tried to make the pins all along 1 edge.

mini-uino_DIP_single_sided.brd (21.5 KB)

mini-uino_DIP_single_sided.sch (146 KB)

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.

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.

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..

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

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.

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! :slight_smile:

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.

xl97:
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

Looks beautiful!

retrolefty:

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

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.

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.

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

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

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.

Yep, you got screwed.
Next purchase, try the ask question option to confirm you're getting the one with pads.

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

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

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.