VCNL3040 Proximity Sensor Library
The VCNL3040 Proximity sensor from Vishay integrates sensing element with high power IR LED in a single small package. This sensor is ideal for detecting if something is in front of sensor. It is made to work up to 30 cm range and adjustable LED current, Duty cycle and integration Time can get useful for application specific integration.
Programmable interrupt feature can help reduce the workload on MCU and decrease power consumption. It is possible to setup low and high thresholds for interrupt. In addition, Proximity detection logic output mode allows to detect closing objects and when it moves away.
Here you will find link to the tindie shop once boards will be up there:
VCN3040 breakout board on Tindie
/i/928471/products/2020-03-29T20%3A11%3A18.100Z-top_bottom.png)
You can find
- /examples - đź‘» TO DO
- /src - Source files for the library (.cpp, .h).
- keywords.txt - Keywords from this library that will be highlighted in the Arduino IDE.
- library.properties - General library properties for the Arduino package manager.
How it works?
start by including this and Wire libraries. Make a VCNL3040 object
#include <VCNL3040.h>
#include <Wire.h>
VCNL3040 sens;
library doesn't call Wire.begin() you should do it yourself in void setup().
Basic functions
sens.begin() - must be called to initialize sensor,
sens.begin(true) - can be used to rest all settings to default.
sens.startReading() - sensor is woken from sleep mode, once this function is called sensor starts performing measurements
sens.sleep()- sensor is powered down in sleep mode.
sens.readPSData() - returns unsigned int value of last measurment value.
sens.readINTFlag() - returns interrupt status
| INT flag value | meaning |
|---|---|
| 0x00 | interrupt not triggered |
| 0x01 | PS drops below PS_THDL (low interupt treshold) |
| 0x02 | PS rises above PS_THDH (high interupt treshold) |
| 0x03 | PS entering protection mode (what is that!?) |
Configuring sensor
There are many things you can configure on VCNL3040.
Vishay has made app note, about how to implement sensor in specific application.
Bolded setting are default ones.
Resolution
There are low and high resoluiton modes for VCNL3040
use function sens.setPSResolution(value) for choosing one
| value | HEX | resolution |
|---|---|---|
| LOW | 0x00 | 12-bit |
| HIGH | 0x01 | 16-bit |
LED current
Use function sens.setLedCurrent(value) as an value you can use on of the specified values from list below
| value | HEX | LED current |
|---|---|---|
| LED_CURRENT_50mA | 0x00 | 50mA |
| LED_CURRENT_75mA | 0x01 | 75mA |
| LED_CURRENT_120mA | 0x02 | 120mA |
| LED_CURRENT_140mA | 0x03 | 140mA |
| LED_CURRENT_160mA | 0x04 | 160mA |
| LED_CURRENT_180mA | 0x05 | 180mA |
| LED_CURRENT_200mA | 0x06 | 200mA |
PS duty
set prefered PS duty using sens.setPSDuty(value)
| value | HEX | PS Duty | measurement time |
|---|---|---|---|
| PS_DUTY_40 | 0x00 | 1/40 | 4.85 ms |
| PS_DUTY_80 | 0x01 | 1/80 | unknown |
| PS_DUTY_160 | 0x02 | 1/160 | unknown |
| PS_DUTY_320 | 0x03 | 1/320 | 40 ms |
Integration time
set PS_IT using sens.setPSIT(value)
| value | HEX | PS_IT |
|---|---|---|
| PS_IT_1T0 | 0x00 | 1T |
| PS_IT_1T5 | 0x01 | 1.5T |
| PS_IT_2T0 | 0x02 | 2T |
| PS_IT_2T5 | 0x03 | 2.5T |
| PS_IT_3T0 | 0x04 | 3T |
| PS_IT_3T5 | 0x05 | 3.5T |
| PS_IT_4T0 | 0x06 | 4T |
| PS_IT_8T0 | 0x07 | 8T |
Interrupt settings
By default setting interrupt is disabled you can enable it by using function
sens.setINTMode(value) - enable interrupt in one of the modes - table below
To effectively adopt PS INT function Vishay recommends trigger by closing mode
| value | HEX | trigger mode |
|---|---|---|
| PS_INT_DISABLED | 0x00 | disabled |
| PS_INT_CLOSING | 0x01 | by closing |
| PS_INT_AWAY | 0x02 | by away |
| PS_INT_CLOSING_AWAY | 0x03 | by closing and away |
there are two interrput modes. You can switch between them using funtions:
sens.enableINTNormalMode() - normal mode is when interrup is triggered.
It stays that way until you read out interrup flag using function sens.readINTFlag()
sens.enableINTProxMode() - proximity interrupt mode
sens.setPSPers(value) - you can choose how many consecutive measurments in tirggering range have to be made to assert interrupt
| value | HEX | count |
|---|---|---|
| PS_PERS_1 | 0x00 | 1 |
| PS_PERS_2 | 0x01 | 2 |
| PS_PERS_3 | 0x03 | 3 |
| PS_PERS_4 | 0x04 | 4 |
interrupt thresholds
There are upper and lower threshold. You can set nedeed value (up to 16-bit) for both of them using functions
sens.setPSTHDL() - for setting lower threshold
sens.setPSTHDH() - for setting upper threshold
TODO LIST
- Example code
- Features from PS_CONF3 register
- Add boards to Tindie
License Information
This code is open source!
Please review the LICENSE.md file for license information.
Please use, reuse, and modify these files as you see fit. Please maintain attribution to my name - Andris Jenerts and release anything derivative under the same license.
Distributed as-is; no warranty is given.