Hi to all Blynkers.
Please, I need some help with an information on Wemos D1 mini pro datasheet.
Can I supply the USB port with an 9V battery? I’m asking this because I did not understand if the “6 - 20 V” limit values of input voltage refers only to the 5V and GND pins.
Are the 5V and 3.3V input voltages too or only output pins?
Thanks for you all.
Can you share the datasheet? I don’t see it on the Wemos site.
Looking at the schematic:
You "should’ be able to supply the micro USB from 9V battery.
5V is an input pin, 3.3v is an output pun (you could theoretically connect external 3.3V to this pin to power the board, but you would have no V or I protection and could easily fry the board with even a small V spike).
cul
billd
Thank you for your answer Bill. In fact I saw this information on a website.
I am asking this because I am having my wemos d1 mini pro board heating the underlined components in the attached figure and I don’t know if this happens for using an 9 V input on the usb port. For months I’ve been using the 5 V USB computer’s port or the 9 V battery for mobile projects. But now using 5 V or 9 V the board starts to heat.
Please, can you inform what components are that?
Thanks a lot.
That’s not a Wemos D1 Mini Pro?
This is, I think:
https://www.wemos.cc/en/latest/d1/d1_mini_pro.html
16Mb instead of the normal 4Mb(ceramic antenna)
Looking at the schematic, they appear to be R3 and R4, which are the 470 ohm resistors connected to the Tx and Rx pins.
Pete.
You’ve got to love (or maybe hate) what Wemos do with their board naming system!
This is the old version (V1) of the D1 Mini Pro, the on in your link is the new version (V2). As they are such a different layout, and physically aren’t really interchangeable with the previous version, they really ought to have called it something else.
Pete.
So the one pictured above is the “old version” (D1 Mini Pro), 4Mb or 16Mb? And ceramic antenna.
And the one I liked to is the latest 16Mb version (D1 Mini Pro) with a PCB antenna?
I didn’t know they made a 16Mb version with a ceramic antenna …
Lets hope the one I dragged out the back of the cupboard last week is the old 16Mb Pro version then …
No, the one pictured is the D1 Mini Pro V1, 16Mb memory, ceramic antenna and external antenna connector (selectable by moving a zero ohm resistor).
Same footprint as the D1 Mini (non pro) version which has 4Mb of memory, no antenna connector and a PCB antenna.
The 16Mb of memory is useless though, as it can’t be used for anything practical, so it’s only really the external antenna connector that makes it interesting. I have occasional use for an external antenna, so I tend to use the Pro (V1) boards for most things.
Pete.
I think this schematic is is for Version 2 of the D1 Mini Pro, as it has the battery connector which doesn’t exist on the Version 1 board (which is what @JCarlos58 is using).
Personally, I wouldn’t power my Wemos D1 Mini devices with anything higher than 5v.
When reading the specs, you should be aware that the Wemos D1 R1 and R2 are basically Arduino UNOs with an ESP8266 processor. The UNO can be powered via USB or the onboard power connector, which accepts a nominal 9v supply. When you look at specs which says that the supply voltage can be 6-20v then you can be fairly certain that this is referring to the nominal 9v connector on the D1 R1/R2, which doesn’t exist on the D1 Mini/Pro.
Pete.
Yep . . . I answered before he clarified with a pic . . . definitely 5V USB only . . .
cul
billd
Thank you all for the answers. I was using the 5 V usb port to upload the code and for the mobile aplication I’ve been used a 9 V battery to supply the wemos.
Have any of you ever had this heating problem for these components?
I don’t know exactly if this problem is due the 9 V input on wemos’ usb port.
Thank you!
