I usually write about projects I’ve made or things I’ve bought, but today I’m sharing a short post about an issue I continually experience with my ESP8266-based Wemos D1 Mini Lite and the Arduino IDE.
Every time I try to upload a new sketch to this board, the upload fails and it spits out an unhelpful ‘warning: espcomm_sync failed‘ message followed by an equally unhelpful ‘error: espcomm_open failed‘, and then finally an unhelpful ‘error: espcomm_upload_mem failed‘!
This doesn’t happen with any of my other Wemos boards, or even any of my other ESP8266 variants – just this ‘Lite’ model.
Anyway, the fix is easy, just apparently not permanent.
Connect power to your Wemos, then use a jumper wire to connect the GND pin to the D3 pin for 1 second. A paperclip or anything else conductive will do the job.
Once you’ve done that, disconnect power, wait another second, then power it up again.
That’s it – this fixes it for me every time and allows me to upload a sketch from the Arduino IDE, however if I then try to upload another sketch over that one the error comes back.
The fix is easy so I don’t mind doing this every time, but I wonder if this is an issue with just my Wemos D1 Mini Lite, or perhaps everyone is experiencing this and it’s a design flaw?
LOLIN (supposedly the official store for Wemos boards) appear to have stopped selling the Lite version – maybe this is why?
Whatever the reason, hopefully this helps a fellow maker or two with this annoying but easy to resolve issue.
Rich
I have encountered this problem so I’ll try this fix. I noticed (after 3 week of getting WINDOWS to give me a COM port) that the ARDUINO IDE (1.8.9) would properly download (with or without the above error) unless I said that my D1 Mini was really a LITE Wemos. I wonder why. With this lie, it works (except for the above error which seems to resolve itself around the third try).