The node-switchbot is a Node.js module which allows you to move your Switchbot (Bot)'s arm and to monitor the temperature/humidity from SwitchBot Thermometer & Hygrometer (Meter).
This module is unofficial. It was developed by reference to the official python code. But some functionalities of this module were developed through trial and error. So some information obtained from this module might be wrong.
The node-switchbot supports only Linux-based OSes, such as Raspbian, Ubuntu, and so on. This module does not support Windows and Mac OS for now. (If @abandonware/noble is installed properly, this module might work well on such OSes.)
See the document of the @abandonware/noble for details on installing the @abandonware/noble.
Note that the noble must be run as root on most of Linux environments. See the document of the @abandonware/noble for details.
Before installing the @abandonware/noble, some linux libraries related Bluetooth as follows if the OS is Ubuntu/Debian/Raspbian.
$ sudo apt-get install bluetooth bluez libbluetooth-dev libudev-dev
If you use other OS, follow the instructions described in the document of the @abandonware/noble.
After installing the libraries above, install the @abandonware/noble and the node-switchbot (this module) as follows:
$ cd ~
$ npm install @abandonware/noble
$ npm install node-switchbot
- Quick Start
SwitchbotobjectSwitchbotDeviceobjectSwitchbotDeviceWoHandobject- Advertisement data
- Release Note
- References
- License
Monitoring the advertising packets, you can find your devices and know the latest state of each device. The packet contains the settings of the device, the arm position of the Bot, the temperature and humidity of the Meter, and so on.
// Load the node-switchbot and get a `Switchbot` constructor object
const Switchbot = require('node-switchbot');
// Create an `Switchbot` object
const switchbot = new Switchbot();
(async () => {
// Start to monitor advertisement packets
await switchbot.startScan();
// Set an event hander
switchbot.onadvertisement = (ad) => {
console.log(JSON.stringify(ad, null, ' '));
};
// Wait 10 seconds
await switchbot.wait(10000);
// Stop to monitor
switchbot.stopScan();
process.exit();
})();The startScan() methods starts to monitor advertisement packets. In order to receive the packets, you have to assign a callback function to the onadvertisement.
The wait() method is just an utility method, which wait for the specified milliseconds.
The startScan() and wait() methods are asynchronous, they return a Promise object. You can write code in promise style as well. What the code below does is as same as what the code above does:
// Load the node-switchbot and get a `Switchbot` constructor object
const Switchbot = require('node-switchbot');
// Create an `Switchbot` object
let switchbot = new Switchbot();
// Start to monitor advertisement packets
switchbot.startScan().then(() => {
// Set an event hander
switchbot.onadvertisement = (ad) => {
console.log(JSON.stringify(ad, null, ' '));
};
// Wait 10 seconds
return switchbot.wait(10000);
}).then(() => {
// Stop to monitor
switchbot.stopScan();
process.exit();
});The sample codes above will output the result as follows:
{
"id": "c12e453e2008",
"address": "c1:2e:45:3e:20:08",
"rssi": -61,
"serviceData": {
"model": "H",
"modelName": "WoHand",
"mode": true,
"state": false,
"battery": 100
}
}
{
"id": "cb4eb903c96d",
"address": "cb:4e:b9:03:c9:6d",
"rssi": -70,
"serviceData": {
"model": "T",
"modelName": "WoSensorTH",
"temperature": {
"c": 25.2,
"f": 77.4
},
"fahrenheit": false,
"humidity": 43,
"battery": 100
}
}See the section "Advertisement data" for the details of the advertising packets.
This sample discovers a Bot (WoHand), then put the Bot's arm down, finally put it up in 5 seconds.
// Load the node-switchbot and get a `Switchbot` constructor object
const Switchbot = require('node-switchbot');
// Create an `Switchbot` object
const switchbot = new Switchbot();
(async () => {
// Find a Bot (WoHand)
const bot_list = await switchbot.discover({ model: 'H', quick: true });
if (bot_list.length === 0) {
throw new Error('No device was found.');
}
// The `SwitchbotDeviceWoHand` object representing the found Bot.
let device = bot_list[0];
// Put the Bot's arm down (stretch the arm)
await device.down();
// Wait for 5 seconds
await switchbot.wait(5000);
// Put the Bot's arm up (retract the arm)
await device.up();
process.exit();
})();In order to manipulate the arm of your Bot, you have to discover your Bot using the discover() method. The object { model: 'H' } passed to the method means that only Bots will be discovered. That is, Meters will be ignored.
In this code, you can get a SwitchbotDeviceWoHand object representing the found Bot. Using the down() and up() methods of the object, you can move the arm. In addition to these methods, you can use the press(), turnOn(), and turnOff() methods as well.
In order to use the node-switchbot, you have to load the node-switchbot module as follows:
const Switchbot = require('node-switchbot');You can get an Switchbot constructor from the code above. Then you have to create an Switchbot object from the Switchbot constructor as follows:
const switchbot = new Switchbot();The Switchbot constructor takes an argument optionally. It must be a hash object containing the properties as follows:
| Property | Type | Required | Description |
|---|---|---|---|
noble |
Noble | option | a Noble object of the @abandonware/noble module |
The node-switchbot module uses the @abandonware/noble module in order to interact with BLE devices. If you want to interact other BLE devices using the @abandonware/noble module, you can create an Noble object by yourself, then pass it to this module. If you don't specify a Noble object to the noble property, this module automatically create a Noble object internally.
The sample code below shows how to pass a Nobel object to the Switchbot constructor.
// Create a Noble object
const noble = require('@abandonware/noble');
// Create a Switchbot object
const Switchbot = require('node-switchbot');
const switchbot = new Switchbot({'noble': noble});In the code snippet above, the variable switchbot is an Switchbot object. The Switchbot object has a lot of methods as described in sections below.
The discover method finds devices. This method returns a Promise object. This method takes an argument which is a hash object containing parameters as follows:
| Property | Type | Required | Description |
|---|---|---|---|
duration |
Integer | Optional | Duration for discovery process (msec). The default value is 5000 (msec). |
model |
String | Optional | "H" or "T". If "H" is specified, this method will discover only Bots. If "T" is specified, this method will discover only Meters. |
id |
String | Optional | If this value is set, this method will discover only a device whose ID is as same as this value. The ID is identical to the MAC address. This parameter is case-insensitive, and colons are ignored. |
quick |
Boolean | Optional | If this value is true, this method finishes the discovery process when the first device is found, then calls the resolve() function without waiting the specified duration. The default value is false. |
In the code snippet below, no parameter is passed to the method:
switchbot.discover().then((device_list) => {
// Do something...
}).catch((error) => {
console.error(error);
});If no parameter is passed to the method as the code above, an Array object will be passed to the resolve() function in 5 seconds. The Array object contains SwitchbotDevice objects representing the found devices. See the section "SwitchbotDevice objects" for more details.
If you want a quick response, you can set the quick property to true.
switchbot.discover({
duration: 5000,
quick: true
});
}).then((device_list) => {
// Do something...
}).catch((error) => {
console.error(error);
});As the quick property is set to true, the resolve() function will be called immediately after a device is found regardless the value of the duration property.
The ondiscover property on the Switchbot object is an event handler called whenever a device is newly found in the discovery process. A SwitchbotDevice object is passed to the callback function set to the ondiscover property.
switchbot.ondiscover = (device) => {
console.log(device.id + ' (' + device.modelName + ')');
};
switchbot.discover().then(() => {
console.log('The discovery process was finished.');
}).catch((error) => {
console.error(error);
});The code snippet above will output the result as follows:
cb4eb903c96d (WoSensorTH)
c12e453e2008 (WoHand)
The discovery process was finished.
The startScan() method starts to scan advertising packets coming from devices. This method takes an argument which is a hash object containing the parameters as follows:
| Property | Type | Required | Description |
|---|---|---|---|
model |
String | Optional | "H" or "T". If "H" is specified, this method will discover only Bots. If "T" is specified, this method will discover only Meters. |
id |
String | Optional | If this value is set, this method will discover only a device whose ID is as same as this value. The ID is identical to the MAC address. This value is case-insensitive, and colons are ignored. |
Whenever a packet is received, the callback function set to the onadvertisement property of the Switchbot object will be called. When a packet is received, a hash object representing the packet will be passed to the callback function.
// Set a callback function called when a packet is received
switchbot.onadvertisement = (ad) => {
console.log(ad);
};
// Start to scan advertising packets
switchbot.startScan({
id: 'cb:4e:b9:03:c9:6d',
}).then(() => {
// Wait for 30 seconds
return switchbot.wait(30000);
}).then(() => {
// Stop to scan
switchbot.stopScan();
process.exit();
}).catch((error) => {
console.error(error);
});The code snippet above will output the result as follows:
{
id: 'cb4eb903c96d',
address: 'cb:4e:b9:03:c9:6d',
rssi: -65,
serviceData: {
model: 'T',
modelName: 'WoSensorTH',
temperature: { c: 25.8, f: 78.4 },
fahrenheit: false,
humidity: 43,
battery: 100
}
}
...
The serviceData property depends on the model of the device. See the section "Advertisement data" for the details of the data format.
The stopScan() method stops to scan advertising packets coming from devices. This mothod returns nothing. Note that this method is not asynchronous but synchronous unlike the other methods. See the section "startScan() method" for details.
If a callback function is set to the onadvertisement property, the callback function will be called whenever an advertising packet is received from a device during the scan is active (from the moment when the startScan() method is called, to the moment when the stopScan() method is called).
See the section "startScan() method" for details.
The wait() method waits for the specified milliseconds. This method takes an integer representing the duration (millisecond). This method returns a Promise object.
This method has nothing to do with Switchbot devices. It's just an utility method. See the section "Quick Start" for details of the usage of this method.
The SwitchbotDevice object represents a Switchbot device (Bot or Meter), which is created through the discovery process triggered by the Switchbot.discover() method.
Actually, the SwitchbotDevice object is an super class of the SwitchbotDeviceWoHand and SwitchbotDeviceWoSensorTH objects. The SwitchbotDeviceWoHand object represents a Bot, the SwitchbotDeviceWoSensorTH object represents a Meter.
You can use the properties and methods described in this section on both Bot and Meter. See the section "SwitchbotDeviceWoHand object" for the details of the functionalities available only on Bot. For now, SwitchbotDeviceWoSensorTH object has no additional functionality.
The SwitchbotDevice object supports the properties as follows:
| Property | Type | Description |
|---|---|---|
id |
String | ID of the device. (e.g., "cb4eb903c96d") |
address |
String | Mac address of the device. Basically it is as same as the value of the id except that this value includes : in the string. (e.g., "cb:4e:b9:03:c9:6d") |
model |
String | This value is "H" which means "Bot (WoHand)" or "T" which means "Meter (WoSensorTH)". |
modelName |
String | This value is "WoHand" or "WoSensorTH". |
connectionState |
String | This value indicates the BLE connection state. "connecting", "connected", "disconnecting", or "disconnected". |
onconnect |
Function | See the section "onconnect event handler" for details. |
ondisconnect |
Function | See the section "ondisconnect event handler" for details. |
The getDeviceName() method fetches the device name saved in the device. This method returns a Promise object.
If no connection is established with the device, this method automatically establishes a connection with the device, then finally closes the connection. You don't have to call the connect() method in advance.
If the device name is fetched successfully, the device name will be passed to the resolve().
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
return device_list[0].getDeviceName();
}).then((name) => {
console.log(name);
process.exit();
}).catch((error) => {
console.error(error);
process.exit();
});The code above will output the result as follows:
WoHandThe setDeviceName() method update the device name saved in the device with the name specified as the first argument. This method returns a Promise object. Nothing will be passed to the resolve() function.
If no connection is established with the device, this method automatically establishes a connection with the device, then finally closes the connection. You don't have to call the connect() method in advance.
The character set of the device name saved in the device is UTF-8. The byte length of the name must be less than or equal to 20 bytes. If the name consists of only ASCII characters, up to 20 characters would be allowed. But if the name consists of multi-byte characters, the upper limit of characters would be fewer than half. For example, Japanese characters could be saved at most 6 characters because most of Japanese characters consume 3 byte per each character.
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
return device_list[0].setDeviceName('Bot in kitchen');
}).then(() => {
console.log('Done.');
process.exit();
}).catch((error) => {
console.error(error);
process.exit();
});The connect() method establishes a connection with the device (i.e., pairing). This method returns a Promise object. If the device has already been connected, this method does nothing and calls the resolve() function immediately.
Most of the methods implemented in the SwitchbotDevice object automatically connect and disconnect the device. But this mechanism would be absolutely inefficient if you want to manipulate the device repeatedly in the short time.
The connection established using the connect() method is not disconnected automatically unless the disconnect() method is explicitly called.
The code snippet below establishes a connection with the Bot using the connect() method, then puts the Bot's arm down, then waits for 5 seconds, then puts the arm down, finally disconnects the device using the disconnect() method:
let device = null;
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
device = device_list[0];
if (!device) {
console.log('No device was found.');
process.exit();
}
console.log(device.modelName + ' (' + device.address + ') was found.');
console.log('Connecting...');
return device.connect();
}).then(() => {
console.log('Putting the arm down...');
return device.down();
}).then(() => {
console.log('Waiting for 5 seconds...');
return switchbot.wait(5000);
}).then(() => {
console.log('Putting the arm up...');
return device.up();
}).then(() => {
console.log('Disconnecting...');
return device.disconnect();
}).then(() => {
console.log('Done.');
process.exit();
}).catch((error) => {
console.error(error);
process.exit();
});The result will be as follows:
WoHand (c1:2e:45:3e:20:08) was found.
Connecting...
Putting the arm down...
Waiting for 5 seconds...
Putting the arm up...
Disconnecting...
Done.
The disconnect() method disconnects the device. This method returns a Promise object. If the device has already been disconnected, this method does nothing and calls the resolve() function immediately.
See the previous section for more details.
The onconnect event hander will be called when the connection with the device is established. Nothing will be passed to the hander.
The code below calls the press() method, while callback functions are attached to the onconnect and ondisconnect.
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
let device = device_list[0];
if (!device) {
console.log('No device was found.');
process.exit();
}
console.log(device.modelName + ' (' + device.address + ') was found.');
// Set event handers
device.onconnect = () => {
console.log('Connected.');
};
device.ondisconnect = () => {
console.log('Disconnected.');
};
console.log('Pressing the switch...');
return device.press();
}).then(() => {
console.log('Done.');
process.exit();
}).catch((error) => {
console.error(error);
process.exit();
});The code above will output the result as follows:
WoHand (c1:2e:45:3e:20:08) was found.
Pressing the switch...
Connected.
Disconnected.
Done.
Seeing the result, you would find the press() method automatically connects and disconnects the device.
The ondisconnect event hander will be called when the connection with the device is closed. Nothing will be passed to the hander. See the previous section "onconnect event handler" for more details.
The SwitchbotDeviceWoHand object represents an Bot, which is created through the discovery process triggered by the Switchbot.discover() method.
Actually, the SwitchbotDeviceWoHand is an object inherited from the SwitchbotDevice. You can use not only the method described in this section but also the properties and methods implemented in the SwitchbotDevice object.
The press() method sends a press command to the Bot. This method returns a Promise object. Nothing will be passed to the resove().
If no connection is established with the device, this method automatically establishes a connection with the device, then finally closes the connection. You don't have to call the connect() method in advance.
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
return device_list[0].press();
}).then(() => {
console.log('Done.');
}).catch((error) => {
console.error(error);
});When the Bot receives this command, the Bot's arm will be put down (stretched), then put up (retracted) in a few seconds.
The turnOn() method sends a turn-on command to the Bot. This method returns a Promise object. Nothing will be passed to the resove().
If no connection is established with the device, this method automatically establishes a connection with the device, then finally closes the connection. You don't have to call the connect() method in advance.
When the Bot receives this command, the Bot's arm will be put down (stretched) or put up (retracted) depending on the mode setting.
| Mode | Inverse the on/off direction | Physical position of the arm |
|---|---|---|
| Press mode | N/A | Down (stretched), then Up (retracted) |
| Switch mode | Disabled | Down (stretched) |
| Enabled | Up (retracted) |
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
return device_list[0].turnOn();
}).then(() => {
console.log('Done.');
}).catch((error) => {
console.error(error);
});The turnOff() method sends a turn-off command to the Bot. This method returns a Promise object. Nothing will be passed to the resove().
If no connection is established with the device, this method automatically establishes a connection with the device, then finally closes the connection. You don't have to call the connect() method in advance.
When the Bot receives this command, the Bot's arm will be put down (stretched) or put up (retracted) depending on the mode setting.
| Mode | Inverse the on/off direction | Physical position of the arm |
|---|---|---|
| Press mode | N/A | Down (stretched), then Up (retracted) |
| Switch mode | Disabled | Up (retracted) |
| Enabled | Down (stretched) |
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
return device_list[0].turnOff();
}).then(() => {
console.log('Done.');
}).catch((error) => {
console.error(error);
});The down() method sends a down command to the Bot. This method returns a Promise object. Nothing will be passed to the resove().
If no connection is established with the device, this method automatically establishes a connection with the device, then finally closes the connection. You don't have to call the connect() method in advance.
When the Bot receives this command, the Bot's arm will be put down (stretched) regardless of the mode setting.
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
return device_list[0].down();
}).then(() => {
console.log('Done.');
}).catch((error) => {
console.error(error);
});The up() method sends an up command to the Bot. This method returns a Promise object. Nothing will be passed to the resove().
If no connection is established with the device, this method automatically establishes a connection with the device, then finally closes the connection. You don't have to call the connect() method in advance.
When the Bot receives this command, the Bot's arm will be put up (retracted) regardless of the mode setting.
switchbot.discover({ model: 'H', quick: true }).then((device_list) => {
return device_list[0].up();
}).then(() => {
console.log('Done.');
}).catch((error) => {
console.error(error);
});After the startScan() method is invoked, the onadvertisement event handler will be called whenever an advertising packet comes from the switchbot devices. An object containing the properties as follows will be passed to the event handler:
| Property | Type | Description |
|---|---|---|
id |
String | ID of the device. (e.g., "cb4eb903c96d") |
address |
String | Mac address of the device. Basically it is as same as the value of the id except that this value includes : in the string. (e.g., "cb:4e:b9:03:c9:6d") |
rssi |
Integer | RSSI. (e.g., -62) |
serviceData |
Object | An object including the device-specific data. |
The structures of the serviceData are described in the following sections.
Example of the advertisement data:
{
"id": "c12e453e2008",
"address": "c1:2e:45:3e:20:08",
"rssi": -61,
"serviceData": {
"model": "H",
"modelName": "WoHand",
"mode": true,
"state": false,
"battery": 100
}
}Structure of the serviceData:
| Property | Type | Description |
|---|---|---|
model |
String | This value is always "H", which means "Bot (WoHand)". |
modelName |
String | This value is always "WoHand", which means "Bot". |
mode |
Boolean | This indicates the mode setting. When the mode is "Switch mode", this value is true. When the mode is "Press mode", this value is false. |
state |
Boolean | This value indicates whether the switch status is ON or OFF. |
battery |
Integer | (experimental) This value indicates the battery level (%). |
The mode can be changed only using the official smartphone app. The node-switchbot does not support changing the mode because the BLE protocol is non-public.
If the mode is false, which means the "Press mode" is selected, the state is always false. If the mode is true, which means the "Switch mode" is selected, the state represents the logical state (ON or OFF). Note that it does not mean the physical arm position. The physical arm position depends on the setting "Inverse the on/off direction" on the official smartphone app.
| "Inverse the on/off direction" | Value of the state |
Logical state | Physical arm position |
|---|---|---|---|
| disabled | true |
OFF | Up (retracted) |
false |
ON | Down (stretched) | |
| enabled | true |
OFF | Down (stretched) |
false |
ON | Up (retracted) |
The battery is experimental for now. I'm not sure whether the value is correct or not. Never trust this value for now.
Example of the advertisement data:
{
"id": "cb4eb903c96d",
"address": "cb:4e:b9:03:c9:6d",
"rssi": -70,
"serviceData": {
"model": "T",
"modelName": "WoSensorTH",
"temperature": {
"c": 25.2,
"f": 77.4
},
"fahrenheit": false,
"humidity": 43,
"battery": 100
}
}Structure of the data:
| Property | Type | Description |
|---|---|---|
model |
String | This value is always "T", which means "Meter (WoSensorTH)". |
modelName |
String | This value is always "WoSensorTH", which means "Meter". |
temperature |
Object | |
c |
Float | Temperature (degree Celsius/°C) |
f |
Float | Temperature (degree Fahrenheit/℉) |
fahrenheit |
Boolean | The flag whether the Meter shows Fahrenheit (true) or Celsius (false) for the temperature on the display |
humidity |
Integer | Humidity (%) |
battery |
Integer | (experimental) This value indicates the battery level (%). |
The fahrenheit indicates the setting on the device. Note that it does not indicate the setting on the official smartphone app. The setting of the temperature unit on the device and the setting on the app are independent.
The battery is experimental for now. I'm not sure whether the value is correct or not. Never trust this value for now.
- v0.0.5 (2020-02-19)
- Improved the stability of discovering the BLE characteristics. (Thanks to @dnicolson)
- v0.0.4 (2020-02-11)
- Fixed the bug that temperature value lower than 0 degC could not be handled. (Thanks to @musimasami)
- v0.0.3 (2020-02-10)
- Now the characteristic UUID
0x2a00(Device Name) is not mandatory. Some models of Bot don't seem to support the characteristic. (Thanks to @dnicolson) - Fixed the bug that the
turnOn()method returns an error if the "Press mode" is selected on the Bot.
- Now the characteristic UUID
- v0.0.2 (2019-11-20)
- First public release
The MIT License (MIT)
Copyright (c) 2019-2020 Futomi Hatano
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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