Faulty Atmel Microcontrollers from Aliexpress

[Luka C]

I'm writing this to warn others or ask if anyone had similar experiences. I purchased a lot of Atmel ATMEGA328P microcontrollers from a seller on Aliexpress. The lot was listed as "new" in the description and had a picture of the microcontroller in the reel so I thought it's a legit new sealed lot. After the package arrived, I noticed the microcontrollers were not in a real and were just randomly taped on a piece of some material with some semitransparent tape. I sent the boards to the local PCB soldering company and they have soldered microcontrollers on the boards. I flashed the program and the first board and it worked just fine so I thought I made a great deal because the price was really good for the lot.

But this is where things became strange, after I was done programming the first board, I tested the other boards. The results were strange to say at least. Some of the microcontrollers came in a "state" where any fuse reprogramming was impossible (btw, SPIEN was not disabled in the fuses!). Two particular microncontroller samples were really strange. 

One seemed to execute really strange sequences of commands without any reason and my nixie clock would get frozen every now and then. Since I own the debugger (Atmel ICE), I decided to debug the firmware on the chip. It turns out that the chip would go really crazy when, for example, 0 and 5 were displayed on the two middle tubes on my clock. The debugger call stack showed that one function was executed when it should not have been and the values of variables in the programmed had values that in no way could be there in the normal program operation.

Second one had trouble outputting data to the LED controller. Debugging this one's firmware showed that the microcontroller was not frozen and in fact was sending data to the LED controller but I guess the data was not properly formatted or something.

There were some boards with perfectly fine chips so I decided to do a simple tested. Since my clock consists of 2 boards, one for the microcontrollers and power supply circuitry and the other one for the nixie tubes and the LEDs, I decided to do a test and swapped the board with the tubes and LEDs across both "working" and "faulty" microcontroller boards. The working ones never produced not a single fault or glitch, I tried to replicate the bugs on them with no success. On the other hand, the faulty ones were impossible to fix even by reflashing the microcontrollers multiple times with the exact same hex filed used to flash the working ones.

At the end, I am confused. I am not sure what to conclude from this really. I believe the fault is not in the board itself (PCB layout or connections) but that it comes from the faulty microcontrollers I have purchased. After doing a little research on the internet, I found some people saying that these Chinese companies basically buy used equipment and remove the microcontrollers from them or that they simply purchased large quantities of chips that have failed quality control and sells them at lower prices. I will try to find a way to remove the faulty ones from the boards and replace them with new ones purchased from RS Components and then do the tests again.

Anyone ever had similar experiences or has any idea why would this happen?

[Terry S]

You my very well have counterfeit micro-controllers.  My suggestion would be to contact your Atmel rep and ask them to de-cap a few to verify. However, when they learn how you bought them, they may not be very willing to do this for you. Of course you would have more leverage if you were a large corporation or large quantity buyer -- through distribution.

I've been down this road several times, every case was parts purchased on the gray market, when nothing was available through distribution.

Terry

[gregebert]

I bought a cheap RTC module ($1 USD, including shpiping) a few years ago, and concluded the DS3231 was either counterfeit, or used/defective material because it was horribly inaccurate. You get what you pay for.

Generally, I only buy parts from a reputable supplier (digikey is my favorite). In particular, semiconductor devices are always packaged in proper ESD-safe bags. During assembly and test/debug, I follow proper handling steps for ESD-sensitive devices. None of those has ever acted erratically.

For me, it's not worth the risk or hassle to save a few dollars on parts by purchasing from the cheapest source.

[NeonJohn]

On 12/17/2016 03:26 PM, Luka C wrote:
> I'm writing this to warn others or ask if anyone had similar experiences. I
> purchased a lot of Atmel ATMEGA328P microcontrollers from a seller on
> Aliexpress.

Microprocessors are one component that you absolutely MUST buy from an
authorized distributor or directly from the manufacturer. ESPECIALLY
Atmel. Instead of trashing chips that fail testing, Atmel apparently
allows them to leave the factory to be sold by unscrupulous resellers.

Atmel is what is known as a foundryless manufacturer. That is they have
hunks of silicon logic manufactured by someone else. They then load
microcode into the chip to turn it into an ATMEGA or whatever.

The nature of this process is that the chip can fail to execute certain
instructions, fail to drive pins while the rest of the chip works.

There can also be parts of the chip that won't run at the specified
speed. I just ran into that with the AT90PWM316. My (now ex) partner
got a "great deal" on some parts through OctoPart. At the programming
frequency loaded into Studio, the chip reported the signature of an
unrelated chip. As a last ditch hunch, I slowed the programming
frequency down to about 50kHz. IT then reported the correct signature
and accepted my program, though it took several minutes instead of seconds.

Since they abruptly and without warning EOL'd that chip shortly after
the MicroChip takeover and the going rate for remaining stock is about
$15 (was $4), I'm going to have to try to use them.

I recently ran into a similar problem, this time with parts from Mouser.
Suddenly with this lot of chips, the "heat" button (induction heater)
works only sometimes and about half the time the unit comes up at full
power instead of the set power level. I haven't yet pin-pointed what is
going wrong so once we use up the OctoPart parts, we'll be down for the
count until I can redesign the board to use a different processor. I'm
fed up with Atmel.

After someone mentioned it here earlier, I took at look at the TI MXP432
ARM processor. About the same price but vastly more powerful. The TI
LaunchPad (think Arduino) is only 12 dollars and is set up like the
Arduino to accept daughterboards. Ti's support has been great. This is
the chip I'm converting to.

Back to the issue at hand, never ever ever buy complex parts whose
origin cannot be traced back to the manufacturer and even then expect
problems.

John


--
John DeArmond
Tellico Plains, Occupied TN
http://www.tnduction.com <-- THE source for induction heaters
http://www.neon-john.com <-- email from here
http://www.johndearmond.com <-- Best damned Blog on the net
PGP key: wwwkeys.pgp.net: BCB68D77

[David Forbes]

I buy parts from Digikey for this reason. They always work. Think how
much money and time you would have saved by spending more on legitimate
components.

--
David Forbes, Tucson AZ

[Nick]

Likewise - as I used to be in the UK, it was Farnell (Element 14, who also own Newark), RS, Rapid or similar. Occasionally, I'd use DigiKey or Mouser, both of whom have UK delivery services at respectable rates.

Out here in the UAE, it's still Farnell but I have to wait two days instead of one :)

Nick

[John Rehwinkel]

> Atmel is what is known as a foundryless manufacturer. That is they have
> hunks of silicon logic manufactured by someone else.

Is that still true, after their acquisition by Microchip?

- John

[NeonJohn]

No idea, though I can't imagine them changing their entire work flow and
methods just like that. The blank silicon may come from MicroChip now.

John

[Luka C]

I agree with what you and the others have said. I should mention, the reason why I want to warn the others about this is because the listings on sites such as Aliexpress/Alibaba actually do say that the component is "original" and "new". If it was marked as refurbished or something like that, I would have never ordered it in the first place. I should also mention that I had many other orders from other sellers for components such as capacitors, resistors, inductors, power ICs, etc...and all of them work 100% fine and came packaged in a sealed reel. I guess it's the microcontrollers that are mostly prone to such scams. 

[Terry S]

Before the Microchip acquisition, Atmel wasn't exactly fabless, they had purchased a few smaller companies that came with fabs. I don't know where the AVR series is made.

The problem is likely counterfeit parts, or die that didn't test 100%, and "leaked" out of fabs... This is more common than chip vendors like to admit. It has happened to TI and Burr-Brown for example. Sometimes good die leak out as well, but the handling and packaging at that point is unreliable.

Terry