MicroPython Forum (Archive)

WeMos have released a D1 Mini Pro.

• ESP-12F replaced with onboard components, no metal cover.
• 16MB flash (128Mbit)
• Built in ceramic antenna + external connector
• CP2104 USB-UART (changed from CH340G)
• Same dimensions as D1 Mini, compatible with existing shields
• Lighter and thinner than D1 mini
• USB + reset buttons moved to the top of PCB
• $1 more expensive than D1 mini

https://www.aliexpress.com/item/WEMOS-D ... .56.5Zx1NW
$5 USD

Odd that the chip isn't shielded: their other products have a WeMos branded, shielded chip. Odder still it doesn't appear on the WeMos official site. I smell a rat.

I ordered a couple, so we will see what this "rat" looks like. I like having the antenna connector as I put all my IoT devices in metal boxes.

pythoncoder wrote:Odder still it doesn't appear on the WeMos official site. I smell a rat.

This is consistent with how their other products first appear at Aliexpress, and only after a couple of days on their website. I think the website is being updated by someone who is quite busy with other things too. It was like that with the motor shield too.

Perhaps I'm being too suspicious, then - but I gather there are a lot of dodgy clones of WeMos devices. I think abandoning shielding represents a decline in build quality and I doubt an unshielded module can achieve FCC approval.

The antenna connection is a great improvement.

I have noticed another curious thing looking at the photo of the new board. There are a lot of vias on the ground fill -- a standard practice to bring the ground planes on both side of the board together, to avoid noise and to improve thermal conducting. Except there is a no ground fill on the other side -- the vias just hang in the air there:



Not sure if this is a design mistake?

deshipu wrote:...Not sure if this is a design mistake?

Surely: I can't imagine a good reason.

For me it looks like the board has more than 2 layers. If you look at the Pins tx, rx, d1, d2, d3, there is a faint shadow of a lower layer at both sides, but no copper on the respective top levels.

I'll post some high res photos once mine arrives

Look at the fiducial, TX pin or ceramic antenna. There are for sure mor layers, probably 4.