Read the receiver with EV3 Classroom in three steps
In EV3 Classroom, the PS2 / PS4 receiver shows up as a LEGO Infrared Sensor. So you do not import a library or add an extension: you read it with the Infrared Sensor blocks. Work through the steps on the left and the blocks on the right grow with you. These block pictures were built in EV3 Classroom 1.5.3 and exported straight from the software, so they look exactly like it.
1
Start: program start + repeat forever
You need to read the sensor again and again. A new project already has the yellow "when program starts" block. Attach "forever" under it and put "wait 0.1 seconds" inside, so it reads every 0.1 seconds.
Open EV3 Classroom and press "New Project".
Drag "forever" from "Control" and attach it under "when program starts".
Drag a "wait 1 seconds" block into forever and change the number to 0.1.
2
Meet the reading blocks (Infrared Sensor)
On the EV3, the PS2 / PS4 receiver shows up as a LEGO Infrared Sensor. So you read it with the Infrared Sensor blocks in "Sensors"; no extension needed. The number at the front of each block is the port: choose 1 (the sensor is in port 1). The product puts different values in different blocks:
Block
What you get
Range
proximity
D-pad
0 to 15
heading to beacon 2
Shape buttons
0 to 15
heading to beacon 3
Shoulder buttons
0 to 15
heading to beacon 4
Function buttons
0 to 15
proximity to beacon 1
Left stick (#1: LX)
0 to 99 (50 = centre)
proximity to beacon 2
Left stick (#2: LY)
0 to 99 (50 = centre)
proximity to beacon 3
Right stick (#1: RX)
0 to 99 (50 = centre)
proximity to beacon 4
Right stick (#2: RY)
0 to 99 (50 = centre)
Use blocks of only one mode in a program (Proximity, Beacon or Remote). Every mode change makes the EV3 pause for about 1.1 seconds.
3
Show it on the EV3 screen
Put the reading block into "write … at line …" from "Display", use "join" from "Operators" to put a name in front (for example POS), and start the program with "clear display". Click a function and the blocks and result change to its example.
Gamepad simulator: click the buttons, drag the sticks, and watch the output on the right
The simulator is only a sketch: click a button once to hold it, click again to let go. Drag the dot on a stick to move it (it stays where you let go; press "Release all" to centre it). On the EV3 the sticks go from 0 to 99, 50 = centre, bigger to the right and up.
Block example for each function
Every value EV3 Classroom can read has a small program you can copy (sensor in port 1). Press "Try it" to jump to step 3.
What EV3 Classroom cannot read: the 16-button number, whether the pad is connected (mode 3), battery, how far L2 / R2 are pressed, PS button and touch pad, pad type, device ID and firmware version. Rumble and light bar (PS4 only) are commands, and the EV3 port cannot send commands. The modes 3 to 6 added in firmware v4.0 (for example millimetre distances, bitmaps, connection state, device ID) cannot be read with EV3 Classroom blocks either. For these, use Pybricks (the EV3 needs a different microSD card) or clev3r.
Things to know
Plug the sensor into port 1. If you use another port, change the port number on the block. Switch the EV3 on first, then plug in the sensor; if the number never changes, unplug it and plug it in again.
Use one mode per program. Each change between Proximity, Beacon and Remote makes the EV3 pause for about 1.1 seconds, and a racing robot can lose control.
When the sensor is unplugged: the EV3 cannot read it, the number becomes "not a number" and the screen shows ----. Each reading also waits about 1.2 seconds. The program does not stop, and it works again when you plug the sensor back in.
One mode is enough: Beacon mode has all the buttons and both sticks at once (heading = buttons, proximity = sticks). A driving program that only uses it never switches modes.
When the pad is not connected: buttons are 0 and sticks are 50 (centre), so the robot does not run off. The PS2 and PS4 receivers give exactly the same numbers on the EV3.
English blocks: EV3 Classroom has only English and Simplified Chinese interfaces; this page uses English.
For complete projects (line following, avoiding obstacles, driving …) see the EV3 examples page; most examples have an EV3 Classroom file to download.