CMM2: DS18B20 Temp sensor problem


Author Message
TassyJim

Guru

Joined: 07/08/2011
Location: Australia
Posts: 6455
Posted: 02:18am 10 Mar 2025      

Found time to test before leaving.

local retailer (Jaycar)

Family name: DS18B20
Rom Code:    28 AA 42 A3 41 14 01 D5
ScratchPad:  51 01 00 00 7F FF 60 10
Power mode   External

ScratchPad:  51 01 FF FF 1F FF 1F 10
Temperature:  21  109.795mS, 9 bit

ScratchPad:  50 01 FF FF 3F FF 3F 10
Temperature:  21  199.835mS, 10 bit

ScratchPad:  50 01 FF FF 5F FF 5F 10
Temperature:  20.875  379.825mS, 11 bit

ScratchPad:  4E 01 FF FF 7F FF 7F 10
Temperature:  21  739.858mS, 12 bit

Tempr() without start   21      210.887
Tempr Start Pin,0       21      110.06
Tempr Start Pin,1       21      209.799
Tempr Start Pin,2       21      409.839
Tempr Start Pin,3       21      809.776

> RUN
Known good.

Family name: DS18B20
Rom Code:    28 62 D8 F1 05 00 00 18
ScratchPad:  50 05 4B 46 7F FF 0C 10
Power mode   External


ScratchPad:  50 05 FF FF 1F FF 0C 10
Temperature:  22  94.519mS, 9 bit

ScratchPad:  60 01 FF FF 3F FF 10 10
Temperature:  21.75  169.149mS, 10 bit

ScratchPad:  5C 01 FF FF 5F FF 04 10
Temperature:  21.75  318.568mS, 11 bit

ScratchPad:  5C 01 FF FF 7F FF 04 10
Temperature:  21.625  617.607mS, 12 bit

Tempr() without start   21.75   210.933
Tempr Start Pin,0       22      109.848
Tempr Start Pin,1       21.75   209.812
Tempr Start Pin,2       21.75   409.785
Tempr Start Pin,3       21.625  809.801


The module purchased form Jaycar 5 years ago is slower that the specs but still just fast enough for the picomite code.
It may give errors in 9 and 10 bit resolution.

Jim