Non-Standard MQTT Protocol

Problems

1. MQTT Device/Gateway Send and Subscribe Topics are inconsistent with platform and cannot be modified. How to access ThingsPanel?

2. MQTT Device/Gateway JSON Message Format is inconsistent with platform specs. How to access ThingsPanel?

Use MQTT Topic Message Converter

Solves both topic and message conversion. It is an external converter implementing a simple broker, performing transformation internally. Data flow: Device -> MQTT Converter -> ThingsPanel MQTT Broker -> ThingsPanel Platform. See code README for details.

Repository: https://github.com/ThingsPanel/mqtt-converter.git

Video Tutorial: https://www.bilibili.com/video/BV1Zh4y127Za/?spm_id_from=333.337.search-card.all.click&vd_source=3205f3f58f033fa90037cb65ee98074c

Use Data Processing Script in Edit Parameters

Solves the second problem.

1. After creating device, click Edit Params, select Custom Protocol in Data Processing dropdown.
2. Enter Uplink Parsing Script and Downlink Parsing Script in the dialog.
3. Save. Can be selected directly when creating other similar devices.
4. Scripts can also process data values.
5. See example below.

Example

Platform Standard Format for Gateway:

{
	"TH180001": {
		"temp": 26.5,
		"hum": 45.5
	},
	"TH180002": {
		"temp": 26.5,
		"hum": 45.5
	}
}

Non-Standard Device Format:

{
	"sensorDatas": {
		"TH180001": {
			"temp": 265,
			"hum": 455
		},
		"TH180002": {
			"temp": 265,
			"hum": 455
		}
	},
	"type": 2
}

Uplink Script Example:

1. Analyze: Extra nesting layer, values need scaling.
2. Create Gateway Device, add two sub-devices. (Sub-device address filled in parameters, must be unique in gateway).
3. Write Code:

   // Debug: Place file in folder, run `node ThingsPanelScriptTestDemo.js`
   function encodeInp(msg, topic){
       // Convert custom msg to json 
       // Input: topic string
       // Input: msg byte[] array
       // Output: string
       var msgString = String.fromCharCode.apply(null, msg)
       var jsonObj = JSON.parse(msgString);
       newObj = jsonObj.sensorDatas
       for(var key in newObj){
           for(var k in newObj[key]){
   	    newObj[key][k] = newObj[key][k]/10
   	}
       }
       msg = JSON.stringify(newObj);
       return msg;
   }
   // String to Byte Array
   const decodedMsg = new Uint8Array([...'{"sensorDatas":{"TH180001":{"temp":265,"hum":455},"TH180002":{"temp":26.5,"hum":45.5}},"type":2}'].map(c => c.charCodeAt(0)));
   console.log(decodedMsg);
   // Debug Code
   const topic = "gateway/attributes";
   const encodedMsg = encodeInp(decodedMsg, topic);
   console.log(encodedMsg); // {"TH180001":{"temp":26.5,"hum":45.5},"TH180002":{"temp":2.65,"hum":4.55}} Note: Output must valid JSON

4. Use online JS tool (e.g. lddgo.net).
5. Paste function into script and save (in Gateway Edit Params).
6. Downlink script is similar.