ESP8266 NodeMCU flashing hangs at 10% problem (and fix)

[hamster_nz]

This is being posted here many because I know it will get indexed, and others here  might be interested....

I was having problems with the first of 10 ESP8266 modules I've acquired from Deal Extreme - I couldn't flash new firmware (NodeMCU) as it would hang at 10%. Tried a whole lot of 'hints' found on the web (jumper this pin to that, hold mouth like so...) with no success.

Nor could I role back to stock firmware, as one of the four sections would fail to write (under both Linux and Windows). Tried different speeds and so on for a few hours...

Running an strace on the script showed it would just lock up after writing a whole lot of FF values - the ESP module would not reply.

So I then looked closer at the Usb/serial bridge (a cheap FT232RL based module). I wired it for loopback (TX jumpered to RX), and wrote the same data to the port - and the FT232RL locked up. Hummm...

I then got a trusted part (an FPGA dev board with a FTDI part on it) and tried the test program. It didn't lock up. So I pushed the RX and TX pins though the FPGA to a pin header, and tried flashing with the world's most expensive serial adapter... and bugger me, it worked.

I've got 10 fake serial adapters!

Just to prove it to myself I replaced the FT232RL with one I had on hand. It now flashes firmware perfectly.... Grrrrr

However, this means I now have a test that can detect these fakes - pretty much just send 10B of FF chars and see it it locks up!

[sporadic]

The ones based off the NodeMCU 1.0 design use the CP2102. I'd probably grab those for your next batch I try to stay away from anything FTDI now!

Sent from my XT1094 using Tapatalk

[ebclr]

It's very smart to avoid FTDI or you will be a semiconductor detective

[kripton2035]

a fake FTDI chip coming from deal extreme is not surprising at all...
like ebclr and sporadic, since the FDTI gate, I try to have other chips than FDTI like CP2102 or CHG340 not to search aftter buy if the chip is real or fake !

[firepower]

Can you post pic of problem ESP8266 board so we know to avoid purchasing same.

[hamster_nz]

It wasn't the ESP module, it was the USB to serial adapter.

http://www.dx.com/p/ftdi-basic-program-downloader-usb-to-ttl-ft232rl-for-arduino-389456

(image attached).

However I am sure that the same design is available with genuine chips on it, so the image doesn't help much.

[ebclr]

Buy this

http://pt.aliexpress.com/item/Free-Shipping-1206-200ohm-200R-1-100pcs-LOT-SMD-Resistor-sample-in-stock-most-value-don/619755100.html?spm=2114.02010208.3.184.rUm7GZ&ws_ab_test=searchweb201556_10,searchweb201602_3_10057_10056_10055_10037_10049_10033_10059_10032_10058_10017_405_404_10040_10060_412,searchweb201603_7&btsid=187eaf03-27f1-45a7-b914-b843c19e04f4

The base board is a perfect programmer

[Kilrah]

However I am sure that the same design is available with genuine chips on it, so the image doesn't help much.

Confirmed, I've got 3 identical-looking ones and they work fine so they must have genuine chips.