Skip to content

Latest commit

 

History

History
322 lines (307 loc) · 7.56 KB

LEGO-EV3-Infrared-Sensor-(45509).md

File metadata and controls

322 lines (307 loc) · 7.56 KB
Raw

General

This sensor uses the [[msensor|Using the Mindstorms Sensor Device Class]] device class.

Value
type_id 33
# Modes 6
Connection UART

Mode 0

Mode 0 Mode 1 Mode 2 Mode 3 Mode 44 Mode 55
mode IR-PROX IR-SEEK IR-REMOTE IR-REM-A IR-S-ALT IR-CAL
Description Proximity IR Seeker1 IR Remote Control2 Alternate IR Remote Control Alternate IR Seeker Calibration???
num_values 1 8 4 1 4 2
value0 Proximity (distance) Channel 1 Heading Channel 1 Channel 13 ???
 Min 0 (very close) -25 (far left) 0 (none) 0 (???) 0 (???)
 Max 100 (far away - approx. 70cm/27in) 25 (far right) 11 (blue up and blue down) 100 (???) 1023 (???)
value1 Channel 1 Proximity Channel 2 ???
 Min 0 (close) 0 (none) 0 (???) 0 (???)
 Max 100 (far away - approx. 200cm/79in) 11 (blue up and blue down) 100 (???) 1023 (???)
value2 Channel 2 Heading Channel 3 ???
 Min -25 0 (none) 0 (???)
 Max 25 11 (blue up and blue down) 100 (???)
value3 Channel 2 Proximity Channel 4 ???
 Min 0 0 (none) 0 (???)
 Max 100 11 (blue up and blue down) 100 (???)
value4 Channel 3 Heading
 Min -25
 Max 25
value5 Channel 3 Proximity
 Min 0
 Max 100
value6 Channel 4 Heading
 Min -25
 Max 25
value7 Channel 4 Proximity
 Min 0
 Max 100
units pct (percentage) pct (percentage) btn (button2) none3 pct (percentage) none
dp (decimal places) 0 0 0 0 0 0
Values in the tables that look like ```this``` are the names of sysfs attributes or values returned by said attributes.

[1]: The absence of a beacon on a channel can be detected when Proximity == -128 (and heading == 0).

[2]: Pressing more that 2 buttons at one time is not supported. It will usually read 0. Pressing an up/down button while beacon mode is activated with turn off beacon mode.

Button values:

Value Description
0 none
1 red up
2 red down
3 blue up
4 blue down
5 red up and blue up
6 red up and blue down
7 red down and blue up
8 red down and blue down
9 beacon mode on
10 red up and red down
11 blue up and blue down

[3]: The most significant byte is always 0x01. In the least significant byte, the 4 most significant bits represent each button. Bit 7 is the blue down button, bit 6 is the blue up button, bit 5 is the red down button, bit 4 is the red up button. Beware that when no buttons are pressed, bit 7 is set (value == 384). You can test that bits 0-3 are all 0 to check this.

if ((value & 0x0F) == 0) {
    // no buttons are pressed
} else {
    if (value & 0x80)
        // blue down button is pressed
    if (value & 0x40)
        // blue up button is pressed
    if (value & 0x20)
        // red down button is pressed
    if (value & 0x10)
        // red up button is pressed
}

Bits 0-3 seem to be some sort of checksum or parity check. Bit 0 = bit 4, bit 1 = ~(bit 5), bit 2 = ~(bit 6), bit 3 = 0 if bits 0-2 are even or 1 if bits 0-2 are odd.

Also, when the beacon mode is active or for about 1 second after any button is released the value is 262. This mode only works with the remote on channel 1.

Values:

Value Blue Down Blue Up Red Down Red Up
262/384
287 X
300 X
309 X X
330 X
339 X X
352 X X
377 X X X
390 X
415 X X
428 X X
437 X X X
458 X X
467 X X X
480 X X X
505 X X X X
X = Button pressed

[4] IR-S-ALT mode does not seem to be usable. When switching to this mode, the sensor quits responding to the keep-alive messages and the sensor resets.

[5] Not sure how this IR-CAL mode is supposed to work. Probably have to write some data to the sensor. Values return 0.