ESP8266 NodeMCU flashing hangs at 10% problem (and fix) - Page 1
Forum section: electronics / general

author: hamster_nz
author_rank: Super Contributor
timestamp: July 23, 2016, 08:23:21 am
content: 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.... GrrrrrHowever, 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!

author: sporadic
author_rank: Regular Contributor
timestamp: July 23, 2016, 10:19:26 am
content: The ones based off the NodeMCU 1.0 design use the CP2102. I'd probably grab those for your next batchI try to stay away from anything FTDI now!Sent from my XT1094 using Tapatalk

author: ebclr
author_rank: Super Contributor
timestamp: July 24, 2016, 05:21:57 am
content: It's very smart to avoid FTDI or you will be a semiconductor detective

author: kripton2035
author_rank: Super Contributor
timestamp: July 24, 2016, 05:53:51 am
content: 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 !

author: firepower
author_rank: Regular Contributor
timestamp: July 26, 2016, 11:22:25 pm
content: Can you post pic of problem ESP8266 board so we know to avoid purchasing same.

author: hamster_nz
author_rank: Super Contributor
timestamp: July 26, 2016, 11:40:57 pm
content: 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.

author: ebclr
author_rank: Super Contributor
timestamp: July 27, 2016, 08:29:50 am
content: Buy thishttp://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-b843c19e04f4The base board is a perfect programmer

author: Kilrah
author_rank: Unknown
timestamp: July 27, 2016, 10:07:15 am
content: Quote from: hamster_nz on July 26, 2016, 11:40:57 pmConfirmed, I've got 3 identical-looking ones and they work fine so they must have genuine chips.