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‎.prettierrc‎

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{}

‎README.md‎

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# Raspberry Pi / Node.js module for the CAP1188 capacitive touch breakout
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The CAP1188 is an 8-channel capacitive touch sensor and is available in a handy [breakout board](https://www.adafruit.com/products/1602). This module enables I2C communication with the chip to easily get information about which pins are being touched. It's based on [Espruino CAP1188 lirrary](http://www.espruino.com/modules/CAP1188.js) which itself is based on the [Adafruit CAP1188 Arduino libary](https://github.com/adafruit/Adafruit_CAP1188_Library).
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## Wiring
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You can wire this up as follows:
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| Device Pin | Pi |
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| ---------- | ------------------------------------------------- |
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| 1 (GND) | [Ground](https://pinout.xyz/pinout/ground) |
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| 2 (VIN) | [3.3v](https://pinout.xyz/pinout/pin1_3v3_power) |
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| 3 (SDA) | [BCM 2/SDA](https://pinout.xyz/pinout/pin3_gpio2) |
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| 4 (SCK) | [BCM 3/SCL](https://pinout.xyz/pinout/pin5_gpio3) |
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## Install
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### Enable I2C on the Pi
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1. `sudo raspi-config`
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2. "Interfacing Options"
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3. "I2C"
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4. "Would you like the ARM I2C interface to be enabled?" -> "YES"
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5. "OK"
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6. "Finish"
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### Install this library
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`npm install --save https://github.com/andrewn/raspi-cap/archive/master.tar.gz`
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## Usage
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Basic usage:
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```js
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const connect = require("raspi-cap").connect;
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// Connect to the CAP1188 breakout.
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// When it's ready, the Promise resolves
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// with the CAP1188 instance
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connect().then(cap1188 => {
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// Returns an array of 8 items for pins C1 - C8
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// true indicates a touch, false is no touch
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// e.g. C6 is being touched
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// [ false, false, false, false, false, true, false, false ]
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const touches = cap1188.readTouches();
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console.log(touches);
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});
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```
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See the [`examples`](./examples) directory for more examples.
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## GUI
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There's a tiny GUI you can run:
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sudo raspi-cap-debug
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It'll show red circles (🔴) for untouched pins and blue circles (🔵) for touched pins.
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## Buying
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* [Adafruit](https://www.adafruit.com/products/1602)
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## Future plans
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* Add support for calling `reset()` to reset the board via the Reset pin

‎bin/cap1188‎

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#!/usr/bin/env node
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const readline = require('readline');
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const connect = require('../').connect;
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let hasLogged = false;
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const logTouches = touches => {
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const moveCursorY = hasLogged ? -1 : 0;
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hasLogged = true;
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readline.clearLine(process.stdout);
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readline.moveCursor(process.stdout, -touches.length, moveCursorY);
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console.log(touches.map(t => (t ? '🔵' : '🔴')).join(' '));
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};
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connect().then(cap1188 => {
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setInterval(() => logTouches(cap1188.readTouches()), 100);
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});

‎examples/cap1188-basic.js‎

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const connect = require('../').connect;
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// Connect to the CAP1188 breakout.
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// Returns a promise that resolves to the
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// CAP1188 instance when it's ready.
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const connectionPromise = connect();
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// When it's ready, begin a loop to read
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// the touches
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connectionPromise.then(cap1188 => {
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setInterval(() => {
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// touches is an array of booleans
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// true means it's touched, false if not
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const touches = cap1188.readTouches();
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console.log(touches);
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}, 100);
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});

‎index.js‎

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const init = require('raspi').init;
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const I2C = require('raspi-i2c').I2C;
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const connect = require('./lib/CAP1188').connect;
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module.exports.connect = ({ i2c = new I2C() } = {}) => {
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return new Promise((resolve, reject) => {
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init(() => {
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const cap1188 = connect(i2c);
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resolve(cap1188);
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});
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});
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};

‎lib/CAP1188.js‎

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/* Copyright (c) 2018 Andrew Nicolaou. See the file LICENSE for copying permission. */
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/*
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Module for Adafruit CAP1188 8-Key Capacitive Touch Sensor Breakout
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Only I2C is supported.
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See: https://www.adafruit.com/products/1602
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A port of the same library for Espruino:
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http://www.espruino.com/CAP1188
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*/
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var C = {
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ADDRESS_DEFAULT: 0x29
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};
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/* Register addresses*/
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var R = {
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MAIN_CONTROL: 0x00,
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SENSOR_INPUT_STATUS: 0x03,
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MULTI_TOUCH_CONFIG: 0x2a,
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STANDBY_CONFIG: 0x41,
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SENSOR_INPUT_LINKING: 0x72,
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LED_OUTPUT_CONTROL: 0x74
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};
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/* Bits within register for functions */
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var B = {
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MAIN_CONTROL_INT: 0x0
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};
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function CAP1188(_i2c, _opts) {
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_opts = _opts == null ? {} : _opts;
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this.i2c = _i2c;
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// Support old API where second param was _addr
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if (typeof _opts === 'number') {
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this.addr = _opts;
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} else {
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this.addr = _opts.address || C.ADDRESS_DEFAULT;
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this.resetPin = _opts.resetPin || null;
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}
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this.initialize();
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}
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/* Initialize the chip */
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CAP1188.prototype.initialize = function() {
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this.linkLedsToSensors();
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this.multipleTouches(true);
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// "Speed up a bit"
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// this.i2c.writeTo(this.addr, [R.STANDBY_CONFIG, 0x30]);
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this.i2c.writeSync(this.addr, R.STANDBY_CONFIG, Buffer.from([0x30]));
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};
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/* Reset the chip if a reset pin has been specified */
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CAP1188.prototype.reset = function(callback) {
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throw new Error('Reset not currently supported');
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var delay = 100,
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pin = this.resetPin,
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self = this;
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if (pin == null) {
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throw new Error('CAP1188 reset called but no resetPin given');
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}
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pin.write(0);
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setTimeout(function() {
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pin.write(1);
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setTimeout(function() {
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pin.write(0);
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setTimeout(function() {
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self.initialize();
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if (callback) {
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callback();
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}
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}, delay);
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}, delay);
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}, delay);
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};
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/* How many simultaneous touches to allow */
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CAP1188.prototype.multipleTouches = function(enable) {
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// 1 will block multiple touches
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this.writeBit(R.MULTI_TOUCH_CONFIG, 7, enable ? 0 : 1);
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};
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/* Link the LED to corresponding sensor */
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CAP1188.prototype.linkLedsToSensors = function() {
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for (var i = 0; i < 8; i++) {
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this.linkLedToSensor(i, 1);
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}
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};
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/* Link LED pin to sensor */
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CAP1188.prototype.linkLedToSensor = function(num, enable) {
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this.writeBit(R.SENSOR_INPUT_LINKING, num, enable);
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};
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/* Read state of all sensors */
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CAP1188.prototype.readTouches = function() {
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var touches = [],
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raw;
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// this.i2c.writeTo(this.addr, R.SENSOR_INPUT_STATUS);
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this.i2c.writeSync(this.addr, Buffer.from([R.SENSOR_INPUT_STATUS]));
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// raw = this.i2c.readFrom(this.addr, 1)[0];
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raw = this.i2c.readSync(this.addr, 1)[0];
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if (raw) {
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// Clear interrupt to be able to read again
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this.writeBit(R.MAIN_CONTROL, B.MAIN_CONTROL_INT, 0);
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}
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for (var i = 0; i < 8; i++) {
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touches[i] = this.getBit(raw, i);
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}
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return touches;
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};
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/* */
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CAP1188.prototype.getBit = function(byt, position) {
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return 1 == ((byt >> position) & 1);
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};
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/* Set a single bit in a register */
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CAP1188.prototype.writeBit = function(reg, bit, val) {
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// this.i2c.writeTo(this.addr, reg);
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this.i2c.writeSync(this.addr, Buffer.from([reg]));
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// var b = this.i2c.readFrom(this.addr, 1)[0];
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var b = this.i2c.readSync(this.addr, 1)[0];
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b = val !== 0 ? b | (1 << bit) : b & ~(1 << bit);
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// this.i2c.writeTo(this.addr, [reg, b]);
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this.i2c.writeSync(this.addr, reg, Buffer.from([b]));
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};
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/* Set more bits in a register */
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CAP1188.prototype.writeBits = function(reg, shift, val) {
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// this.i2c.writeTo(this.addr, reg);
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this.i2c.writeSync(this.addr, Buffer.from([reg]));
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// var b = this.i2c.readFrom(this.addr, 1)[0];
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var b = this.i2c.readSync(this.addr, 1)[0];
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b = b | (val << shift);
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// this.i2c.writeTo(this.addr, [reg, b]);
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this.i2c.writeSync(this.addr, reg, Buffer.from([b]));
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};
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exports.connect = function(_i2c, _addr) {
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return new CAP1188(_i2c, _addr);
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};

‎package-lock.json‎

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‎package.json‎

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{
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"name": "raspi-cap",
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"version": "0.0.1",
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"description":
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"Raspberry Pi / Node.js module for the CAP1188 capacitive touch breakout ",
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"main": "index.js",
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"bin": {
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"raspi-cap-debug": "./bin/cap1188"
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},
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"scripts": {
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"test": "echo \"Error: no test specified\" && exit 1"
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},
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"homepage": "https://github.com/andrewn/raspi-cap",
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"bugs": {
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"url": "https://github.com/andrewn/raspi-cap/issues"
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},
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"os": ["linux"],
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"keywords": ["raspberry pi", "cap1188", "touch"],
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"author": "Andrew Nicolaou <[email protected]>",
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"license": "Apache-2.0",
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"dependencies": {
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"raspi": "^5.0.2",
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"raspi-i2c": "^6.1.0"
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}
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}

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