Newer members of the Arduino supported family of units, this one specially made us curious.
Development of sketches for this Wemos D1 or Lolin D1 was a challenge wich resulted in a very complete piece of software.
A large memory capacity, and Configuration of the unit via Rocrail made it possible to create one sketch, covering all
planned and/or required tasks.
The unit enables a wide variety of connections, but through restrictions in timing, , some functions have to be chosen for.:
More and more very nice power supplies are available, making the use of transformers 'out of date'.
All systems on board work with 3.3 or 5 Volt.
But making a 5 Volt power line, is not a good idea.
The power loss in many occasions might come unacceptable for a certain task, like servo's.
Therefore, this board is equipped with a switching regulator, and the power supply for this unit can be anything between 12 and 24 Volt dc or between 10 and 18 Volt ac.
The total VA (Volt x Ampere) should be at least 20 VA.
So also a normal train transformer is useful here.
The switching regulator has a selection for the output voltage, which should be set to 5V.
It can be done by the on-board trimmer, but I prefer to use the voltage selector on the bottom side of the regulator board.
Taking off the trimmer totally, assures that no accidental voltage change can occur.
This will be the way kits will be configured.
The used processor here, Lolin D1 Mini, only provides a few I/O pins, so a combination of various functions
is not always possible, since they work on the same pin.
But the configuration in Rocrail will provide a simple selection of the desired task.
Since this board is using same firmware as other WIO related units, the complete concept
is explained in one page. https://wiki.rocrail.net/doku.php?id=arduino:wio-en
| Pin # |
| Function |
| Function |
| Function |
|3||port 1||port 9||port 17||port 25|
|4||port 2||port 10||port 18||port 26|
|5||port 3||port 11||port 19||port 27|
|6||port 4||port 12||port 20||port 28|
|7||port 5||port 13||port 21||port 29|
|8||port 6||port 14||port 22||port 30|
|9||port 7||port 15||port 23||port 31|
|10||port 8||port 16||port 24||port 32|
|Se1 to Se4 servomotor|
Both connectors are linked together all 4 pins.
The power to these connectors can be selceted with between 5V and 3,3V by Jp1.
See indication on pcboard.
|Pins|| function |
|4||5V / 3,3V||5V / 3,3V|
This is a standard serial connector, which can be used to connect variious units, as far as WIO support them.
^ Pinsetting RC1 ^
This connection was planned to use for connection booster, long before WIOCtrl was developed.
BS1 is still useable to drive a universal booster like ORD-3 or ORD-VC-1.
|1||DCC line 1|
|2||DCC line 2|
To connect a chain of 2812 Leds, (max 128).
The limit is absolute 128, but with all leds full on, the power supply is by far not sufficient.
In that case, external 5V supply should be used to connect to the led chain.
For use with RC522 sensors.
The pins are one to one identical with the RC522 sensors.
PIN5 and PIN7 does have to be wired, but wiring will do no harm.
More about the RC522 RFID sensor can be found here: