In the official LEGO SPIKE App (Education edition, SPIKE 3), the Pathfinder 16-Way shows up as a Color Sensor. So you do not import a library: you read it with the Color Sensor blocks and then convert the numbers into line position and line width. Work through the steps on the left and the blocks on the right grow with you. These block pictures were built and exported straight from the official web App (spike.legoeducation.com), so they look exactly like the App.
You need to read the sensor again and again. First place the yellow "when program starts" block and attach "forever" under it. Put "wait 0.1 seconds" inside, so it reads every 0.1 seconds.
The official App reads the Pathfinder 16-Way with three Color Sensor blocks. Each block starts with a port drop-down: pick the port the Pathfinder is plugged into. You must convert the numbers you read to get the line position:
| Official block | What you get | Conversion |
|---|---|---|
| reflected light (in Sensors) | line position (coarse) + 16 | subtract 16 from the reading → -16 to 16 |
| color (in Sensors) | line width (how many channels are on the line) | use it as it is → 0 to 16, 0 = no line |
| raw red (in the "More Sensors" extension) | line position (fine) + 100 | subtract 100 from the reading → -100 to 100 |
To use raw red, first press the extension button at the bottom left of the App and add "More Sensors".
In "Variables", make a new variable (for example "line position"). Use "set … to …" to store the converted value in it. This gives the value a name. After that, use this variable to show the value or to test it. Click a function and the blocks and result change to its example.
The simulator is only a sketch: the conversion is simplified, so a real sensor may differ by one or two steps. The darker the circle, the darker that channel sees. Red ring = that channel counts as on the line.
Every function the official App can read has a set of blocks you can copy (port C). Press "Try it" to jump to step 3.
What the official App cannot read: the official App only reads the sensor's "combined data". So it cannot read the Pathfinder 16-Way's line segments, light value of each channel (raw green / blue only hold a rough 0 to 3 that you would have to split into bits; not for beginners), which channels are on the line, sensor ID, firmware version or sensor connected. For these, use the MBC SPIKE Blocks website or Pybricks (the hub needs Pybricks firmware).