node-web-i2c
Version:
I2C access with Node.js
225 lines (224 loc) • 7.07 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.requestI2CAccess = exports.OperationError = exports.I2CPort = exports.I2CPortMap = exports.I2CAccess = void 0;
const i2c_bus_1 = require("i2c-bus");
/**
* I2C Port Map Max サイズ
*/
const I2CPortMapSizeMax = 32;
/**
* Uint16 Max サイズ
*/
const Uint16Max = 65535;
/**
*
* Uint16型変換処理
* @param parseString 変換文字列
* @return Uint16型変換値
*/
function parseUint16(parseString) {
const n = Number.parseInt(parseString, 10);
if (0 <= n && n <= Uint16Max)
return n;
else
throw new RangeError(`Must be between 0 and ${Uint16Max}.`);
}
/**
* I2CAccess クラス
*/
class I2CAccess {
_ports;
/**
* Creates an instance of GPIOAccess.
* @param ports ポート番号
*/
constructor(ports) {
this._ports = ports == null ? new I2CPortMap() : ports;
}
/**
* ポート情報取得処理
* @return 現在のポート情報
*/
get ports() {
return this._ports;
}
}
exports.I2CAccess = I2CAccess;
/** Different from Web I2C API specification. */
class I2CPortMap extends Map {
getByName(portName) {
const matches = /^i2c-(\d+)$/.exec(portName);
return matches == null ? undefined : this.get(parseUint16(matches[1]));
}
}
exports.I2CPortMap = I2CPortMap;
/**
* I2CPort クラス
*/
class I2CPort {
_portNumber;
/**
* Creates an instance of GPIOPort.
* @param portNumber ポート番号
*/
constructor(portNumber) {
this._portNumber = parseUint16(portNumber.toString());
}
/**
* ポート番号取得処理
* @return 現在のポート番号
*/
get portNumber() {
return this._portNumber;
}
/**
* ポート名取得処理
* @return 現在のポート名
*/
get portName() {
return `i2c-${this.portNumber}`;
}
/**
* I2CSlave 接続デバイスオープン処理
* @param slaveAddress 接続デバイス情報のアドレス
* @return I2CSlaveDevice インスタンスの生成の完了
*/
async open(slaveAddress) {
const bus = await (0, i2c_bus_1.openPromisified)(this.portNumber).catch((error) => {
throw new OperationError(error);
});
return {
slaveAddress,
/**
* @function
* I2C 読み取り処理
* @param registerNumber 読み取りアドレス
*/
read8: (registerNumber) => bus.readByte(slaveAddress, registerNumber).catch((error) => {
throw new OperationError(error);
}),
/**
* @function
* I2C 読み取り処理
* @param registerNumber 読み取りアドレス
*/
read16: (registerNumber) => bus.readWord(slaveAddress, registerNumber).catch((error) => {
throw new OperationError(error);
}),
/**
* @function
* I2c s/I2c/I2C 書き込み処理
* @param registerNumber 書き込みアドレス
* @param byte 書き込みの値（バイト）
*/
write8: async (registerNumber, byte) => {
try {
await bus.writeByte(slaveAddress, registerNumber, byte);
return byte;
}
catch (error) {
throw new OperationError(error);
}
},
/**
* @function
* I2c bytes 書き込み処理
* @param registerNumber 書き込みアドレス
* @param word 書き込みの値（ワード）
*/
write16: async (registerNumber, word) => {
try {
await bus.writeWord(slaveAddress, registerNumber, word);
return word;
}
catch (error) {
throw new OperationError(error);
}
},
/**
* @function
* I2c bytes 読み取りバイト処理
* Different from Web I2C API specification.
*/
readByte: async () => {
try {
const byte = await bus.receiveByte(slaveAddress);
return byte;
}
catch (error) {
throw new OperationError(error);
}
},
/**
* @function
* I2c bytes 読み取りバイト処理
* Different from Web I2C API specification.
* @param length 読み取る配列の長さ
*/
readBytes: async (length) => {
try {
const { bytesRead, buffer } = await bus.i2cRead(slaveAddress, length, Buffer.allocUnsafe(length));
return new Uint8Array(buffer.slice(0, bytesRead));
}
catch (error) {
throw new OperationError(error);
}
},
/**
* @function
* I2c bytes 書き込みバイト処理
* Different from Web I2C API specification.
* @param byte 書き込みの値
*/
writeByte: async (byte) => {
try {
await bus.sendByte(slaveAddress, byte);
return byte;
}
catch (error) {
throw new OperationError(error);
}
},
/**
* @function
* I2c bytes 書き込み処理
* Different from Web I2C API specification.
* @param bytes 書き込みの値の配列
*/
writeBytes: async (bytes) => {
try {
const { bytesWritten, buffer } = await bus.i2cWrite(slaveAddress, bytes.length, Buffer.from(bytes));
return new Uint8Array(buffer.slice(0, bytesWritten));
}
catch (error) {
throw new OperationError(error);
}
},
};
}
}
exports.I2CPort = I2CPort;
/**
* 操作エラー
*/
class OperationError extends Error {
/**
* Creates an instance of OperationError.
* @param message エラーメッセージ
*/
constructor(message) {
super(message);
this.name = this.constructor.name;
}
}
exports.OperationError = OperationError;
// Web I2Cの仕様に基づく意図的なasync関数の使用なので、ルールを無効化
// eslint-disable-next-line
async function requestI2CAccess() {
const ports = new I2CPortMap([...Array(I2CPortMapSizeMax).keys()].map((portNumber) => [
portNumber,
new I2CPort(portNumber),
]));
return new I2CAccess(ports);
}
exports.requestI2CAccess = requestI2CAccess;