I have spent a bit of time looking and am not finding what I think should be simple.
I ordered the following board and adapter for an Arduino Nano.
Arduino Nano Adapter
The web IDE doesn’t seem to be able to connect to the board on the USB port (unless I am missing something)… I don’t have an “online/IoT” adapter to “register” with the web ui.
How do I get the NCD4Relay library installed in the Arduino IDE or get the code from the web ide to the Nano connected via USB?
I would love to be able to use these boards for several projects without reversing a library that should be available.
The nano adapter will plug into relay board iot socket. The arduino nano will plug into nano adapter.
You will connect arduino nano to your PC via USB and select arduino nano as your controller in arduino ide.
I have it assembled, can upload a sketch to the nano via USB.
I asked about getting access to the library so I don’t have to code the I2C communication from scratch.
I spent way too much time with the web and desktop particle.io stuff…
The very simple answer is
Use this library in your Arduino IDE https://github.com/ncdcommunity/Arduino_Library_MCP23008_8Channel_Relay_Controller
It is for an 8 channel relay module, but is based on the same/compatible I2C chip.
The code example (included with the library) toggles relay 5 on pin4.
I added pins 0-3 to the sample sketch and was able to access relays 1-4 respectively. Works flawlessly!!