obniz/obniz/libs/io_peripherals/spi.js

obniz sdk for javascript

const ObnizUtil = require('../utils/util');
const semver = require('semver');

class PeripheralSPI {
  constructor(Obniz, id) {
    this.Obniz = Obniz;
    this.id = id;
    this._reset();
  }

  _reset() {
    this.observers = [];
    this.used = false;
  }

  addObserver(callback) {
    if (callback) {
      this.observers.push(callback);
    }
  }

  start(params) {
    let err = ObnizUtil._requiredKeys(params, ['mode', 'frequency']);
    if (err) {
      throw new Error("spi start param '" + err + "' required, but not found ");
    }
    this.params = ObnizUtil._keyFilter(params, [
      'mode',
      'clk',
      'mosi',
      'miso',
      'frequency',
      'drive',
      'pull',
      'gnd',
    ]);
    let obj = {};

    let ioKeys = ['clk', 'mosi', 'miso', 'gnd'];
    for (let key of ioKeys) {
      if (this.params[key] && !this.Obniz.isValidIO(this.params[key])) {
        throw new Error("spi start param '" + key + "' are to be valid io no");
      }
    }

    obj['spi' + this.id] = {
      mode: this.params.mode,
      clock: this.params.frequency, //name different
    };
    if (this.params.clk !== undefined) {
      obj['spi' + this.id].clk = this.params.clk;
    }
    if (this.params.mosi !== undefined) {
      obj['spi' + this.id].mosi = this.params.mosi;
    }
    if (this.params.miso !== undefined) {
      obj['spi' + this.id].miso = this.params.miso;
    }

    if (this.params.drive) {
      if (this.params.clk !== undefined)
        this.Obniz.getIO(this.params.clk).drive(this.params.drive);
      if (this.params.mosi !== undefined)
        this.Obniz.getIO(this.params.mosi).drive(this.params.drive);
      if (this.params.miso !== undefined)
        this.Obniz.getIO(this.params.miso).drive(this.params.drive);
    } else {
      if (this.params.clk !== undefined)
        this.Obniz.getIO(this.params.clk).drive('5v');
      if (this.params.mosi !== undefined)
        this.Obniz.getIO(this.params.mosi).drive('5v');
      if (this.params.miso !== undefined)
        this.Obniz.getIO(this.params.miso).drive('5v');
    }

    if (this.params.pull) {
      if (this.params.clk !== undefined)
        this.Obniz.getIO(this.params.clk).pull(this.params.pull);
      if (this.params.mosi !== undefined)
        this.Obniz.getIO(this.params.mosi).pull(this.params.pull);
      if (this.params.miso !== undefined)
        this.Obniz.getIO(this.params.miso).pull(this.params.pull);
    } else {
      if (this.params.clk !== undefined)
        this.Obniz.getIO(this.params.clk).pull(null);
      if (this.params.mosi !== undefined)
        this.Obniz.getIO(this.params.mosi).pull(null);
      if (this.params.miso !== undefined)
        this.Obniz.getIO(this.params.miso).pull(null);
    }

    if (this.params.gnd !== undefined) {
      this.Obniz.getIO(this.params.gnd).output(false);
      let ioNames = {};
      ioNames[this.params.gnd] = 'gnd';
      this.Obniz.display.setPinNames('spi' + this.id, ioNames);
    }
    this.used = true;
    this.Obniz.send(obj);
  }

  writeWait(data) {
    if (!this.used) {
      throw new Error(`spi${this.id} is not started`);
    }
    if (semver.lte(this.Obniz.firmware_ver, '1.0.2') && data.length > 32) {
      throw new Error(
        `with your obniz ${
          this.Obniz.firmware_ver
        }. spi max length=32byte but yours ${
          data.length
        }. Please update obniz firmware`
      );
    }

    let self = this;
    return new Promise(function(resolve, reject) {
      self.addObserver(resolve);
      let obj = {};
      obj['spi' + self.id] = {
        data: data,
        read: true,
      };
      self.Obniz.send(obj);
    });
  }

  write(data) {
    if (!this.used) {
      throw new Error(`spi${this.id} is not started`);
    }
    if (semver.lte(this.Obniz.firmware_ver, '1.0.2') && data.length > 32) {
      throw new Error(
        `with your obniz ${
          this.Obniz.firmware_ver
        }. spi max length=32byte but yours ${
          data.length
        }. Please update obniz firmware`
      );
    }

    let self = this;
    let obj = {};
    obj['spi' + self.id] = {
      data: data,
      read: false,
    };
    self.Obniz.send(obj);
  }

  notified(obj) {
    // TODO: we should compare byte length from sent
    let callback = this.observers.shift();
    if (callback) {
      callback(obj.data);
    }
  }

  isUsed() {
    return this.used;
  }

  end(reuse) {
    let self = this;
    let obj = {};
    obj['spi' + self.id] = null;
    this.params = null;
    self.Obniz.send(obj);
    if (!reuse) {
      this.used = false;
    }
  }
}
module.exports = PeripheralSPI;