R4DCB08 FAQ
Customer :
Hello Rachel,
I would like to ask for your help and would be very grateful if you have a solution...
I have several R4DCB08 modules from you here.
They work wonderfully and are used successfully in some projects.
Now there's a problem where I think you, as developers, probably have a solution or know other people who have the knowledge.
Feel free to forward my email to anyone else who might be able to help me. Thanks in advance!
But now to the problem!
Reading positive temperatures is no problem. But reading temperatures equal to or less problematic.
Do you have an example with an Arduino UNO, MEGA, how to solve the problem?
I've attached the file for the Arduino UNO/MEGA with further information.
I hope this will solve the problem!
Kind regards to China
Eletechsup :
For example: Read CH2 temperature value:
Send data(RS485 address is 1)：01 03 00 01 00 01 D5 CA
Returns data：01 03 02 FF 90 F9 D8
FF90 is the temperature value, the highest bit is 1, so the temperature is negative, it is converted to decimal = 65424, (65424-65536)/10=-11.2 is the current temperature value
65533 -65536 = -3（-0.3℃）
65530 -65536 = -6（-0.6℃）
65626 -65536 = -10（-1.0℃）
65519 -65536 = -17（-1.7℃）
65516 -65536 = -20（-2.0℃）
Customer :
Problem solved, error found... You just have to read all the pages in the documentation properly...
page2
"FF90 is the temperature value, the highest bit is 1, so the temperature is negative, it is converted to decimal = 65424, (65424-65536)/10=-11.2 is the current temperature value"
I'm ashamed that I bothered you, but I'm also happy that I've finally been able to solve the problem. .