Bc35 & bc95 onenet mqtt (old)

Recently, I worked on a project MQTT The connection of , Because the ECS and the remote module are often updated , Some knowledge of what we have done in the past few years has become unusable , Have to continue to explore , Strange things happened during this period , Make some notes here , So that I can see later .

1、BC35 The module has been discontinued , The current use is BC95, But it is universal in theory , In fact, there are still some differences in the signal interface , Specific in datasheet It doesn't say , Only actual tests . Mainly uart Interface level , It used to be 3.0V Voltage domain , and 3.3 Communication plus interface circuit or 1k The above resistance , But in BC95 On 1k The resistance needs to be modified to 200-500, Otherwise, the communication fails .

2、BC35 There are many 3 Firmware versions , One is with onenet Of , other 2 One is without , Generally, what you can buy at present is not brought , You need to burn it yourself . Not recommended BC35,BC95 Have your own ONENET Version on sale , It supports the new version MQTT（ No test to guess ）. Another problem is that the factory mqtt The agreement may be 3.1 Of , But for now oennet On is 3.1.1, This needs to be configured by yourself , Otherwise, you can't even connect .....

3、 The mobile MQTT Don't confuse the old version with the new version , The new version is more complicated than the old version , Need to calculate password , The old version doesn't need . This project uses the old version MQTT, convenient .

4、ONENET The old version of the MQTT Use fx Connect

fx Sign in
This old version mqtt Login is very simple , So don't confuse the old version with the new version , It's easy to get into a dead end .

5、 The general low-end demand is to display the uploaded information on the cloud , Don't read other technical articles in the past for the next few steps , I don't know if it's due to the revision , Anyway, it's wrong to look at it .

Do not subscribe after connecting “$dp”,$dp,dp such , Just leave it blank
Do not subscribe after connecting ！ Don't subscribe to ！ Don't subscribe to ！( If you want to use the system “$dp”, Upload to the cloud to display ).

6、 Send messages directly , Sending message format depends on the message format , This is in onenet There are documents on . Specifically

file
See this document for details .

Message format
7、 Try to use fx Send message . Okay , You can't publish , Because the system message is “$dp”,butyesonenetOfTechnologyTechniquewritingfilessay了Nothea$ The subscription . This is embarrassing , To do .... Only according to this agreement , So I searched for a long time and found a good software

This is this. , It's easy to use

Use directly after login json Data upload , You can see the data on the system , Premise is json It's full , This fx There is a good function to see whether the format is correct .

Custom subscription
To customize topic Hair json data
To this topic send out json data , You can check whether the data format is correct at the subscriber , You can also find other software to view the format by yourself .

8、 So you can use it AT+QMTPUB=0,0,0,0,"$dp" Sent （ Never subscribe to this system topic）？ Still not . This is about to go back to the message format , The front and 3 Bytes? , need 01( Format ),2 Bit data length , Plus the data , This manual operation is also difficult , This requires the use of SCM , It is directly converted into an array and sent , But you have to debug and see what to do ？

Or this software , It can automatically put json convert to hex, In this way, the serial assistant can send directly , But remember to bring it 3 Byte header ！

9, Now use BC95 The function of is finished . however , Some projects are for configuring servers , product id It is more convenient , Will choose to bring flash, Power on the module that automatically goes to the cloud , I just bought one ebyte Of ea01, I thought it would be easy to buy it , little does one think , This thing is also God company , No technical support , You need to explore step by step … Finally, press bc95 The process is slowly trying step by step , The tutorial on the official website is customized topic And mirroring topic, There is no need to have data on the cloud , No way . The final process is also similar , But he needs to subscribe to this $dp Of topic Of （ Actually, you need to subscribe , It's just fx You can't , and simulate This software can be subscribed by itself ）, And then send , Then you can send it all the time .

10, Actually, I bought it first EA01, I bought it after I really couldn't do it BC35, Then buy BC95, adopt 95 All modules have been adjusted . author ：ding526637566 https://www.bilibili.com/read/cv16923988?spm_id_from=333.999.0.0 Source ：bilibili