A while back, [heypete] needed to get a GPS timing receiver talking to a Raspberry Pi. The receiver only spoke RS-232, and the Pi is TTL level serial. [Pete] picked up a few RS-232 to TTL conversion boards from an online vendor in China. These boards were supposedly based on the Max3232, a wonderchip that converts the TTL serial to the positive and negative voltages of RS-232 serial. The converters worked fine for a few weeks, before failing, passing a bunch of current, and overheating.

On Mouser and Digikey, the Max3232 costs about $1.80 in quantity one, and shipping is extra. You can pick up a ‘Max3232 converter board’ from the usual online marketplaces for seventy five cents with free shipping. Of course the Chinese version is fake. [Pete] had some nitric acid, and decided to compare the die of the real and fake Max3232s.

Investigating Fake MAX3232 TTL-to-RS-232 Chips
https://blog.heypete.com/2016/09/11/investigating-fake-max3232-ttl-to-rs-232-chips/

A while back I needed to interface a GPS timing receiver that only has an RS-232 serial connection with one of my Raspberry Pis. The Pi only supports TTL-level serial and only tolerates voltages between 0-3.3V its the UART pins.

Enter the MAX3232, a chip from Maxim Integrated that converts between RS-232 and TTL serial with supply voltages from 3.0 to 5.5V. It produces “true” RS-232-level voltages (both positive and negative) using built-in charge pumps and some small external capacitors. Just the ticket for what I needed.

Alas, the MAX3232 isn’t really something one can run down to the local electronics shop

Hobbyists like myself need to turn to the internet where such things are available in abundance for cheap from China, though one must be wary of counterfeits.

Of course, I could order from legitimate Swiss distributors, but small-quantity pricing and shipping are extremely high (>$10 USD per chip!) compared to major US distributors like DigiKey and Mouser.

In my case, I ended up buying a few boards like this one from an online vendor in China. The listing specifically states it had a MAX3232 chip.

To the naked eye, everything seemed to be reasonable. The chip did have markings identifying it as a MAX3232 (falsely, as I later discovered; read on!).

However, the first board failed after a few weeks, drew significant current, and dramatically overheated. By “overheated” I mean “blister-raising burn on my fingertip”-level-hot. Also, the data-transfer LEDs were glowing faintly all the time rather than flickering on and off when data was flowing.

I swapped it out for another board

Although it didn’t catch fire (thankfully!), it did fail after a few weeks and overheated just like the first one.

Anyway, the markings are inconsistent and seem pretty low-quality. Definitely not something I’d expect from Maxim. For comparison, I had ordered a free MAX3232 sample directly from Maxim

According to the date code, I ended up killing this chip in the name of science about 2-4 weeks after it was made. Sorry, little guy. Anyway, you can see the markings of the real chip are distinctly different from the fake chips. The differences are striking even with a handheld magnifying glass

Next, I decapsulated all three chips (two fake and one genuine) by dissolving them in hot nitric acid followed by an acetone wash and a few minutes in the ultrasonic cleaner. Don’t try this at home

you can see the fake die is much smaller, has a much different appearance, and didn’t use gold bond wires.

Both chips had the same markings: they appear to have been designed in November 2009, and the marking on the second line appears to be “WWW01”

So far the replacements (either transplanted MAX3232s hand soldered onto the cheap Chinese boards after the fake chips blow up, or other reputable modules with genuine Exar SP3232s) have been going well

RS-232 is still the most popular interface for balances and scales. It is often described as “simple”, however, when things don’t work as expected, finding the cause can be difficult.

When you’ve tried everything and still can’t reliably communicate with your scale via RS-232, there’s a chance a fake chip may be the cause.

Just a few weeks ago, the thought of encountering counterfeit ICs in digital scales had not crossed my mind. Thanks to FTDI’s recent attempt to “brick” counterfeits via Windows Update, fake chips are now a hot topic on the web. While I don’t agree with the way FTDI tried to punish the end user, I wish the controversy had occurred a few weeks earlier. This would have saved me a lot of time.

Back then I was doing the final QC for several scales which were about to be shipped to a customer. The last item on my checklist was “bidirectional communication using RS-232”

Eventually, I arrived at the conclusion that something was very wrong with the MAX232CPE+ chips, which are responsible for converting TTL signals to RS-232 levels. After doing some research on the internet*, I started to suspect those chips were counterfeit. It seemed like a far-fetched idea** at the time, but I still desoldered them, took a few pictures and sent them to Maxim Integrated.

Fake MAX232CPE+ and MAX232EPE+
Counterfeit MAX232CPE+

Fake, fake and fake.

Thankfully, I received a reply in less than two hours:

“Yes these parts are counterfeit, they do not match markings of lots we manufactured.”

Now extremely suspicious of all MAX232s***, I disassembled a few more scales from 4 different suppliers. 3 contained ICs belonging to the MAX232 family, so I sent the pictures to Maxim Integrated, too. In addition to the chips used by the scale manufacturer which had prompted me to start this investigation, one chip used by another manufacturer was also flagged as counterfeit.

To be fair, my sample size is too small to draw meaningful conclusions regarding the entire weighing industry. However, if you’re in the business of making weighing instruments and were blissfully unaware of this issue, I hope this article serves as a wake-up call.

I just received a shipment of some RS232 to TTL converters from China exactly like the ones here.

Out of the whole shipment NONE worked.

Upon further investigation, I replaced the “max232″ with a real one, and it worked every time. I did this for a few others and they also worked.

The chip itself has markings on it “MAX232 CSE +1027″.
They were a good deal. I should have known it was too good to be true.

Many fake manufacturers from China are doing that! Sparkfun also reported similar ancient with ATMega328: SparkFun Electronics

I suspect that many of the electronic components sold by Chinese eBay sellers are counterfeit. The prices are just way too good on many of these parts. China is the land of reverse engineering, and I’ll bet a good percentage of these parts, while they might work well enough, are not genuine.

I know of a few guys who got burned buying a large QTY of avr’s from china (one guy bought 500 pcs!). They lost alot of $$.
In my situation, these items quickly appeared, immediately lots of ebay sellers flooded the marketplace.

Through the final months of 2016 and into 2017 then the first badge prototypes came together.

The replacement for their socket with the plastic protrusions turned out to overlap the edge of the board enough to touch the next panelised board during pick-and-place, and PCBWay, their manufacturer and one of their sponsors, pulled off some heroic mass reworking to deliver the goods. All seemed well, and the boards were manufactured and despatched from China to Europe.

When the completed boards arrived, they worked perfectly. Or at least, they seemed to. It soon became apparent that for about half the boards though there was an unexpected problem in that a switch from USB to battery power would reset the ESP32. This was eventually traced to the Silicon Labs USB to serial chip, and a fix had to be concocted.

It’s a Fake!

The Silicon Labs part had been chosen due to ease of software drivers across all platforms compared to familiar alternatives such as the FTDI chip. Silicon Labs themselves had provided some sponsorship in the form of a significant number of the chips, but that had not been sufficient for the whole production run.

The remainder had to be sourced in China, and as some of you are probably guessing at this point, the chips from China turned out to be fakes.

Even then, they weren’t bad fakes, they performed as you’d expect the original to, but their designer had made a crucial omission in leaving out a protection diode on the USB lines. The resulting spike on disconnection was thus enough to reset the ESP32, spelling potential disaster for the project.

If you know where to go on the Internet, you can pick up an FTDI USB to Serial adapter for one dollar and sixty-seven cents, with free shipping worldwide. The chip on this board is an FTDI FT232RL, and costs about two dollars in quantity. This means the chips on the cheap adapters are counterfeit. While you can buy a USB to serial adapter with a legitimate chip, [Syonyk] found a cheaper solution: buy the counterfeit adapters, a few genuine chips, and rework the PCB.

Why is [Syonyk] replacing non-genuine chips with the real FTDI?
The best reason is FTDIgate Mk. 1
FTDIgate Mk. 2

Comment:

Or just don’t bother and buy a board/cable with another UART to USB chip – like the Chinese CH340, Microchip’s MCP2200 or similar.

Reworking the counterfeit boards does not make any economical sense, IMO. If you really need the features of the FTDI chip (like the bitbang mode) then buy a board with genuine chip. If you don’t (and most people don’t), then just go for one of the above and be done with it – and you will still save money. They are equally well (or better) supported than the old FTDI chip that doesn’t use a standard CDC class driver.

Fixing Fake FTDI FT232RL Adapters (SSOP-28 rework with an iron)
https://syonyk.blogspot.fi/2017/03/fixing-fake-ftdi-ft232rl-adapters-ssop.html

The chips aren’t fake in the “Oh, the factory ran an extra few shifts off the books” sense. They’re fake in the “The fake chips are actually a microcontroller programmed to behave (almost) exactly like the FT232R” sense – and, they do a pretty good job at low speeds!

Zeptobars did some analysis and demonstrated that the fake chips are completely different under the hood, and then of course FTDI messed with their drivers to either brick the fake chips or insert garbage data if you’re using one on Windows.

Fake FT232R Identification

FT232R chips have a unique ID burned into them – at least, the legitimate ones do. The fakes have an ID, but it’s hardly unique – the same ID will be reused extensively before a new ROM is spun. This makes identifying the fakes easy – buy a few, and if they all have the same name, they’re fake!

Another way is to search for your chip’s serial number. A50285BI is a common fake one, and if you see any hits for your serial number on Google, it’s almost certainly a fake.

I set out to replace my fake chips with legitimate chips. I wanted reliable 3M baud communication, and also hands on experience with surface mount rework (I’ve not done it before). Since the adapters are cheap and the legitimate chips are cheap-ish ($4.50/ea in small quantities), it seemed like a good project to start out with.

When it comes to electronic hobbyists and EEs, there is no company that deserves a few raised eyebrows than FTDI. They made their name with USB converter chips, namely USB to serial chips that are still very popular today. So popular, in fact, that clones of these chips are frequently found in the $2 Arduinos from China, and other very low-cost devices. A little more than a year ago, a few clever people noticed FTDI drivers were bricking these counterfeit chips by setting the USB PID to 0000. The Internet reacted to this move and FTDI quickly backed down from that position. The Windows driver was fixed, for about a year until the same shenanigans were found again.

Adafruit recently sat down with [Fred Dart], CEO of FTDI, giving us all the first facts and figures that aren’t from people frustrated with Windows’ automatically updated drivers. The most interesting information from [Fred Dart] is how FTDI first found these counterfeit chips, what FTDI chips are being counterfeited, and how many different companies are copying these chips.

The company first realized they were being cloned when they couldn’t reproduce results of a Chinese-made ‘FTDI’ USB to RS232 cable that behaved strangely. A sample of the cables were shipped to FTDI and after inspecting the chip inside, FTDI found it was a clone with a significantly different architecture than a genuine chip.

Exclusive interview with Fred Dart – CEO of FTDI @FTDIChip #FTDI @adafruit
https://blog.adafruit.com/2016/02/08/exclusive-interview-with-fred-dart-ceo-of-ftdi-ftdichip-ftdi-adafruit/

FTDIgate 2.0?

Edit: Confirmed to be the standard behavior of the FTDI driver for a year now, but now comes back up because of the new driver beeing spread out by windows update. For a fix look at #msg854401

Okay… connecting RX to TX actually reads back “NON GENUINE DEVICE FOUND!”. A brief google search tells me that that’s actually not new.

Because they’re tired of fakes on the market?

Sure, as if I would buy genuine FTDI chips now :-DD
All new devices I have use the CH340G. Sending random characters on the RS232 interface may cause really bad things to existing products and the buyer often had no chance to know that he bought a fake chip… |O But that all had been discussed a year ago.

So, just a warning for you all, be aware of the new FTDI driver coming with windows update!

I have no problem using FTDI, or buying anything that uses FTDI. Don’t buy knockoff crap and it’s not a problem. On the off-chance you do end up getting a knockoff chip in a legitimate product, talk to the manufacturer so they can RMA it and get their supply lines sorted out.

I’ve tried older drivers 2.10.00 and 2.08.30, both give me “NON GENUINE DEVICE FOUND!”. Can these chips now be permanently bricked??

I think the fake chips are fine. But since FTDI cannot brick the counterfeit chips anymore they just send some garbage (“NON GENUINE DEVICE FOUND!”) over their data endpoints. Doing so won’t brick the chips but they will still render the products using them useless. I guess only the Windows driver can do this scam because for Linux, the source code for FTDI driver should be available and such behavior won’t be tolerated into a Linux kernel driver. Can you try these boards on a Linux machine?

I have no problem using FTDI, or buying anything that uses FTDI. Don’t buy knockoff crap and it’s not a problem. On the off-chance you do end up getting a knockoff chip in a legitimate product, talk to the manufacturer so they can RMA it and get their supply lines sorted out.

That’s great if you are a patient end-user consumer with a non-critical application and no particular time schedule.
And buying something expensive enough to come with the bare minimum of “Customer Service”.

Okay, got it back working
If you manually select an older driver, like 2.08.30, you have to change the driver not only on the obvious “USB Serial Port (COMx)” (ftdiport.inf) but also the corresponding “USB Serial Converter” (ftdibus.inf) listed under “USB-Controller” in the device manager. After changing BOTH to 2.08.30, the chip works fine again. It is easy to see if you list the devices by connection.

Guess with the new driver being rolled out by windows update at the moment that might be a trap for lots of us, not having had to deal with this pain in the ass stuff for more than a year now.

Just over a year ago, FTDI, manufacturers of the most popular USB to serial conversion chip on the market, released an update to their drivers that bricked FTDI clones. Copies of FTDI chips abound in the world of cheap consumer electronics, and if you’ve bought an Arduino for $3 from a random online seller from China, you probably have one of these fake chips somewhere in your personal stash of electronics.

After a year, we have the latest update to FTDI gate. Instead of bricking fake chips, the latest FTDI drivers will inject garbage data into a circuit. Connecting a fake FTDI serial chip to a computer running the latest Windows driver will output “NON GENUINE DEVICE FOUND!”, an undocumented functionality that may break some products.

FTDI gate mk. 1 merely bricked fake and clone chips, rendering them inoperable. Because fakes and clones of these chips are extremely common in the supply chain, and because it’s very difficult to both tell them apart and ensure you’re getting genuine chips, this driver update had the possibility to break any device using one of these chips. Cooler heads eventually prevailed, FTDI backed down from their ‘intentional bricking’ stance, and Microsoft removed the driver responsible with a Windows update. Still, the potential for medical and industrial devices to fail because of a random driver update was very real.

The newest functionality to the FTDI driver released through a Windows update merely injects unwanted but predictable data into the serial stream. Having a device spit out “NON GENUINE DEVICE FOUND!” won’t necessarily break a device, but it is an undocumented feature that could cause some devices to behave oddly.

Topic: FTDIgate 2.0?
http://www.eevblog.com/forum/microcontrollers/ftdi-gate-2-0/

CP2102
https://www.silabs.com/Support%20Documents/TechnicalDocs/CP2102-9.pdf

CP210x USB to UART Bridge VCP Drivers
https://www.silabs.com/products/mcu/Pages/USBtoUARTBridgeVCPDrivers.aspx

The CP210x USB to UART Bridge Virtual COM Port (VCP) drivers are required for device operation as a Virtual COM Port to facilitate host communication with CP210x products.