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Just a guess here but the NS73M is not 5V tolerant. The pins connected to the PIC should be level compensated to match the logic levels required for the NS73M or a 3V PIC should be used.

I use...

There isn't much difference between the Sensirion and 1wire CRC calculations. The Sensirion tests Bit 7 of the data and does a left shift for the next test bit whereas the 1wire version tests Bit 0...

I've placed Sensirion CRC code in the code examples section. I've been meaning to do this for some time (year or so) but your question prompted me into action.....

Three different routines to calculate the Sensirion CRC as used in their temperature/humidity sensors.



Sensirion CRC
'Choose one of the following CRC routines. The table based one is the...

You are jumping around the subroutine upon start up right? If your software is verbatum to what you posted then you need to add Goto Start just before the CRC8: label and place a Start: label before...

JohnB,

I'm away from my hardware so I can't test your code. However it appears you have not initialized CRC before you test the first byte. Add CRC=0 right after your Main: label before you...

Hi PaulBarter,

I've just completed a data logging project with the USB Wiz, a device that has both Alfat and USB on it. It appears from your description that the communications is about the same...

Using other 1wire devices I have been able to do the following:

' Read the next 32 bytes, calculate running CRC but discard the bytes
For Index = 1 to 32
OWIn OWPort, 0, [CRCData]
GoSub...

I'm not a VB person, don't even own a copy to try your routine.

The routines I wrote were for the Dallas Semiconductor CRC8 check. Any other CRC routine may not work in the same manner. I note...

You should read Dallas Application note #27 Understanding and using cyclic redundancy checks.

You will need to select one of the three provided crc8 routines and put that in your PBP program. You...

I am not familiar with the DS18S20 but a quick look at the data sheet shows the CRC is calculated by reading all 8 bytes of the scratchpad memory, running them through the CRC routine and comparing...

More than likely no.

You don't state which and I may not be familiar with the 1 wire device you are using but normally you would not be able to skip any characters it transmits. They would all...

Three separate Dallas CRC16 routines.

Note: for some reason spaces are being added to some of the table entries. I tried to edit them out but they returned. They need to be removed before the...

I have just posted 3 PBP routines to calculate Dallas 8bit CRC in the Code Examples area. You may find something to help you there.

Three different PBP programs to calculate the Dallas 8bit CRC.


' PIC16F628
' These routines are documented in Dallas Semiconductor Application Note 27
' Understanding and Using Cyclic...