Loading...

You have no items in your shopping cart.

 
 
 
×

Registration

Profile Informations

Login Datas

or login

First name is required!
Last name is required!
First name is not valid!
Last name is not valid!
This is not an email address!
Email address is required!
This email is already registered!
Password is required!
Enter a valid password!
Please enter 6 or more characters!
Please enter 16 or less characters!
Passwords are not same!
Terms and Conditions are required!
Email or Password is wrong!
Captcha is required!
Captcha is wrong!

ITEAD Intelligent Switch 433MHz Communication Protocol

ITEAD intelligent switch adopts 433MHz wireless frequency band for data communication, using OOK modulation, and indicates 0 and 1 by simple coding via duty cycle. We know that actually this is not very stable nor reliable, however, as a single live wire power supply can only provide a continuous current of less than 100uA, we cannot use reliable communication modes such as  Bluetooth or Wifi. 433MHz simple modulation communication is a compromise with regard to the power supply and distance problems, which allows the direct communication distance of the switch reaches 30 meters, thus transmission between ordinary rooms through the wall can be done easily.

Next, we will describe data transmission format of the ITEAD intelligent switch in details. Data transmission between the switches is consisted of 4 data streams + exit code, while each data stream is made up of boot code + 32-bit data as shown in the following figure.

It can be seen from the timing sequence above that boot code is constituted of a piece of 400us high level plus a 10ms low-level signal, followed by a 32-bit data which is formed by an 8-bit command with a 24-bit IDKEY. For buttons of intelligent switch, each IDKEY is unique.Data 0 is constituted of a piece of 400us high level plus a piece of 400ms low level; while data 1 is constituted of a piece of 400us high level plus a piece of 1.2ms low level. The boot code and 32-bit data will be sent out repeatedly for four times so that the data receiving terminal can effectively receive the first data no matter how harsh the environment is. Finally, the end code is made up of a piece of 400us high level, 10ms low level and 400ms high level. Thus a command is completely sent out.

We know that you will certainly complain why not use the codes with fixed length instead of equivalent length. In fact, initially we designed a 400us high level plus 1.2ms low level to represent data 1 and 1.2 ms high level plus 400us low level to represent data 0, so that data are with equivalent lengths: long 1.6ms . However, because of many reasons, the final protocol was amended to the format above, which is a compromise with regard to a combination of all the circumstances.

The firmware of intelligent switch now supports the following commands:

  • Control ON: 0x02 + 24-bit IDKEY
  • Control Off: 0x03 + 24-bit IDKEY
  • Control reverse status: 0x01 + 24 IDKEY
  • Request pairing command: 0x40000000
  • ON status: 0x06 + 24-bit IDKEY
  • OFF status: 0x07 + 24-bit IDKEY
  • Successful pairing command: 0x50 + 24-bit IDKEY

If the status of a button on the intelligent switch is changed via control by your device, remote control or manual touch, it will send its current status information in about 0.4s after the status is changed. The current status of the corresponding key can be obtained by capturing this information.

The contents above is the communication mode used by the intelligent switch. As we know, we cannot control it directly by cellphone by way of 433MHz, because cellphone does not support wireless communication of 433MHz band. Therefore, we made an intelligent transit box to  perform wireless transfer from cellphones to 433MHz. In order to support these control commands, we need to create a simple command protocol for the cellphones as well, so that the cell phones or other terminals can send commands to control the switches via Bluetooth.

Following table is a simple control protocol we made for Bluetooth communication of cellphones:

Note * parity bit is the parity sum of byte 2 to byte 5.
The cellphone sends the corresponding command via Bluetooth, then the transit box can convert it into corresponding intelligent switch command and sends it to the intelligent switch in the way of 433MHz wireless communication protocol.