Wemos Lolin D1 Mini Pro V2 (HCWEMO0018)

[admin]

The WeMos D1 mini PRO is a miniature wireless 802.11 (Wifi) microcontroller development board. It turns the very popular ESP8266 wireless microcontroller module into a fully fledged development board. Programming the D1 mini pro is as simple as programming any other Arduino based microcontroller as the module includes a built in microUSB interface allowing the module to be programmed directly from the Arduino IDE (requires the ESP8266 support to be added via board manager) with no additional hardware.

The D1 mini Pro is also designed to allow Wemos compatible shields to be plugged into the board in a similar way to the Arduino development board platform, which greatly expands its capabilities. There is already a large range of compatible shields available and these can also be purchased via our website.

New V2.0 features: This version now includes a lithium battery charging circuit (500mA max) and header which allows the module to be powered from a 3.7V single cell lithium battery.







Features:

11 digital input/output pins
Interrupt/pwm/I2C/one-wire
1 analog input(3.2V max input)
16M bytes(128M bit) Flash
External antenna connector
Built-in PCB antenna
Lithium battery interface, 500mA Max charging current
LOLIN I2C Port
Compatible with Arduino, MicroPython, NodeMCU


Operating Voltage: 3.3V
Digital I/O Pins: 11
Analog Input Pins: 1(Max input: 3.2V)
Clock Speed: 80MHz/160MHz
Flash: 16M bytes
Length: 48mm
Width: 25.4mm
Weight: 4.5g



Pinout:









Drivers

The Wemos D1 mini includes a CH340 USB to UART IC to allow it to be programmed directly from the USB port of a computer.

USB 32/64 bit drivers for Microsoft Windows computers can be downloaded from our Github page here:
https://github.com/HobbyComponents/CH340-Drivers



Windows Installation Instructions

Drivers are available in the link below. Simply download and unzip them, connect your D1 Mini to your computer with a USB cable and when the new hardware is detected, point the wizard to the folder you just unzipped to and it should install without any problems.

Windows Driver here




MAC installation instructions


New code signed version confirmed to work with 10.12 Sierra

CH34x_Install_V1.3.zip

Download the driver (you must be logged in to download).

Once downloaded, double-click the zip file to unzip it.

Run installer found in that folder.

If asked to restart, do not restart just yet.

Now restart your Mac.





Adding board support to the Arduino IDE

Latest versions of the Arduino IDE allow for adding additional 3rd party board support directly from within the Arduino IDE. To add support simply open up your Arduino IDE and follow these steps:

1) Go to File->Preferences

2) In the window that opens up find the text box labeled 'Additional Boards Manager URLs:' and paste the following line into it:

http://arduino.esp8266.com/stable/packa ... index.json

Then click the OK button to close the window.

3) Next go to Tools->Board->Boards Manager

4) In the window that opens up look for the entry titled 'esp8266 by ESP8266 Community Version x.x.x' and click on it.

5) In the bottom right-hand corner of this entry you should now see an install button appear. Click on this and board manager will then automatically add all the files necessary to support the ESP8266. This may take a few minutes depending on the speed of your internet connection.

6) Under tools->board you should now see additional board options for various ESP8266 devices including one called 'WeMos D1 mini Pro'.


Schematic:

sch_d1_mini_pro_v2.0.0_HCWEMO0018.pdf

Disclaimer: Libraries, example code, and diagrams are provided as an additional free service by Hobby Components and are not sold as part of this product. We do not provide any guarantees or warranties as to their accuracy or fitness for purpose.

Descriptions and diagrams on this page are copyright Hobby Components Ltd and may not be reproduced without permission.

[DAJ]

Nice addition to the range, though physically a bit larger than the Version 1 D1 mini. The battery connection and charging circuit will be particularly useful.

I have A couple of questions:

1. Is the pinout the same as on the V1 part? It looks it, but as the pins are differently named it's hard to be sure.
2. What is the pinout of the battery and I2C connections, and what connectors are used?

Will you be selling compatible Li-Ion batteries and connectors?

Cheers, Daniel.

[andrew]

Is the pinout the same as on the V1 part? It looks it, but as the pins are differently named it's hard to be sure.

Yes the pinout is the same it's just for some reason Wemos have decided to use the actual ESP8266 pin names. If you take a look at the forum thread for the older version there is a table that shows this mapping,,,

http://forum.hobbycomponents.com/viewto ... 111&t=2126

What is the pinout of the battery

Looking into the connector the left pin is +Ve (VBAT) and the right pin -Ve (GND)

and I2C connections

Same as for other version of the D1 mini - SCL is GPIO5 (D1) and SDA is GPIO4 (D2). Also you can reference the table in the link above.

and what connectors are used?

I assume you are asking about the battery connector? If so it is a JST 2.0 PH 2 pin connector

Will you be selling compatible Li-Ion batteries and connectors?

For the connectors we do plan to have these on sale soon although I can't give you an exact time frame for when they will be on sale. For the batteries we are currently trying to find a competitive supplier of good quality lithium batteries.

[malves61]

Sorry for bumping into an old thread. What is the connector is used on the i2C port?

[andrew]

It's a 4 pin JST SH1.0

[dqj999]

I recently bought 2 Wemos Lolin D1 Mini Pro V2 boards from Hobby Components, I was initially able to program them and use WiFi. After returning to work on them after a break I found that I could not see them via USB as Serial Ports on my Win 10 PC.
I found that if I pressed and held the reset button down then the devices could be seen as Serial Port but only when I held the Reset button down on the processor board.
This seems to be somewhat of a common issue with these boards. Is there any way to get these working again? I can use esptool to send commands to the boards, and I have also tried connecting D2 to Ground before resetting which I believe puts the board in bootloader mode.

Here is an example of what happens when trying to reprogram the board using the Cloud

Code: Select all

Sketch uses 273896 bytes (26%) of program storage space. Maximum is 1044464 bytes.
Global variables use 28364 bytes (34%) of dynamic memory, leaving 53556 bytes for local variables. Maximum is 81920 bytes.

Flashing with command:C:/Users/dqj99/.arduino-create/esp8266/esptool/2.5.0-3-20ed2b9/esptool.exe -vv -cd nodemcu -cb 921600 -cp COM3 -ca 0x00000 -cf C:/Users/dqj99/AppData/Local/Temp/arduino-create-agent542129925/Test1.bin
esptool v0.4.13-1-gf80ae31 - (c) 2014 Ch. Klippel <ck@atelier-klippel.de>
	setting board to nodemcu
	setting baudrate from 115200 to 921600
	setting port from COM1 to COM3
	setting address from 0x00000000 to 0x00000000
	espcomm_upload_file
	espcomm_upload_mem
	setting serial port timeouts to 1000 ms
opening bootloader
resetting board
trying to connect
	flush start
	setting serial port timeouts to 1 ms
	setting serial port timeouts to 1000 ms
	flush complete
	espcomm_send_command: sending command header
	espcomm_send_command: sending command payload
	read 0, requested 1
.... several repeats
warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed
Executing command: exit status 2

[andrew]

After returning to work on them after a break I found that I could not see them via USB as Serial Ports on my Win 10 PC.
I found that if I pressed and held the reset button down then the devices could be seen as Serial Port but only when I held the Reset button down on the processor board.

The D1 Mini Pro uses a separate CH340 USB chip for the USB-to-serial interface, so the USB COM port should always appear on your computer, regardless of the firmware flashed onto the processor.

Are you by any chance using the same USB cable to test both boards?

My thinking is if there is a bad/high impedance connection with either the cables GND or 5V lines then you may be getting too much voltage drop at the board end. Holding down the reset button would hold the processor in a low power mode which would then result in a lower volt-drop along the cable. Maybe enough to then make the CH340 start working.

If you have a multimeter you may also want to check the 5V & GND pins.

[dqj999]

Thanks for that suggestion about checking the 5V rail. I measured the voltage between the 5v Pin and the Gnd pin on the board and that was 3.4v. The 3.3V pin measured 3.0v to Gnd.

So I think that something is not quite right with the power. I see from the diagram that there is a "fuse" between the USB input and the 5v pin, and I'm wondering now whether this has gone high resistance.

I'll try providing some external power to the chip and see if that improve matters.

Derek Johnson

[andrew]

I measured the voltage between the 5v Pin and the Gnd pin on the board and that was 3.4v. The 3.3V pin measured 3.0v to Gnd.

I see from the diagram that there is a "fuse" between the USB input and the 5v pin, and I'm wondering now whether this has gone high resistance.

You could try probing either side of the fuse wrt to GND. If one side is ~5V and the other is 3.4V then that would confirm it.

[dqj999]

Thanks again. I’ve now tried a couple of things including powering the board from a USB power bank and then
swapping the connection to the PC from a USB3.0 output to a USB 2.0 output.

The boards are now behaving correctly and the Serial port is always active. Looks like USB3.0 ports can be problematical, of course it could just be an issue related to my individual PC.

Derek