Project

General

Profile

Yet another decode problem!

Added by mugginsjm almost 2 years ago

Hi
I have a RFM 12 unit which transmits
Oil depth
Temperature 1
Temperature 2
Temperature 3
With a structure of 16, 10, 10, 10 bits
I am trying to pull the data into Node-red and decode using javascript.
I have been struggling for days on this but I’m lost.
If I structured all 4 measurements as 16 bits, it is easier to decode, but will I be able to see negative temperatures?

Thanks
John



Replies (2)

RE: Yet another decode problem! - Added by JohnO almost 2 years ago

0x"10 11 12 13 14 10"

I don't know javascript but the first 16 bits should be easy, working from the left:

Oil depth: pick up 0x11 and shift it left 8 bits then add in the 0x10. Because the low order eight bits are transmitted first followed by the high order eight bits.

The rest is harder for my head but here is my stab at it.
Temperature 1: pick up (0x13 AND with 0xC0) then shift left 2 bits and then add in 0x12. Because only 2 bits of Temperature 1 are contained in 0x13.

Not sure anymore if the two bits of Temperature 1 are stored in the high order or low order two bits of 0x13.

I don't see an problem sending the sign assuming your definitions are correct and have sufficient bits.

Converting them all to 16 bits will make life easier.

RE: Yet another decode problem! - Added by mugginsjm almost 2 years ago

Thank you for the response. I have taken the easy path and just converted all to 16 bits and now I just have to deal with 4 pairs of numbers.

    (1-2/2)