1-Wire RF temp sensor 310/433.92MHz

[b_weijenberg]

An RF temperature sensor is available now for the US frequency too (see products at http://www.rfxcom.com) It has a protocol which is compatible with the Digimax but without the set function. The ACRF plug-in does not yet support the sensor but it is expected soon.
The RFXtemp device has one 1-Wire DS18B20 sensor connected and an second DS18B20 sensor can be connected easily with a 3-pole jack connector.

Bert

[DrRick]

Noob question

I have a W800RF32, am in the US, and would like to wirelessly monitor temperature in a couple of places (attic and basement, should have power in one place, but may not in the other). A few questions:

1) will the W800RF32 work with these 1 wire temp sensors (I read on the RXCOM site that it will work, but will not get error information)?
2) if so, what sensors will work with it?
3) if not, what do I need?

Thanks!
Rick

[b_weijenberg]

Hello Rick,

First we have to wait until Jon has made the RFXtemp device available in the ACRF plug-in and I think this will be somewhere in the 1st half of January.

1. Yes, the W800RF32 will receive the RFXtemp signals.
2. I suppose you have a 310MHz W800 and in that case:
40060 310MHz RFXtemp with 1 sensor
or 50005 310MHz RFXtemp with 2 sensors will work.

I suggest you to wait ordering until the ACRF plug-in is ready.

Some explination of the data packets send by the RFXtemp and received by the receivers.
The W800 will receive the 1st 4 bytes only while the RFXCOM receiver receives all 5 1/2 bytes.

Message examples:
temperature packet: B12D0415009
The 1st 2 bytes (B12D) is the device address of the sensor
The 3rd byte (04) is a parity byte to check the address validity
The 4th byte (15) is the measured temperature 15 hex=21 decimal
The 5th byte (00) is not used in a temperature packet
The 6th half byte (9) is a parity byte to check the validity of byte 4 and 5.
!!! The W800 will receive 4 bytes so the measured temperature is received.

error packet: B12D040001E
The 1st 2 bytes (B12D) is the device address of the sensor
The 3rd byte (04) is a parity byte to check the address validity
The 4th byte (00) is not used in an error packet
The 5th byte (01) is an error code. 01= No 1-wire device connected
The 6th half byte (E) is a parity byte to check the validity of byte 4 and 5.
!!! This packet will be seen by the W800 as a zero degrees temperature packet and not as a packet with an error code. This is because only the 1st 4 bytes are seen by the W800.

For more detailed information see also the Documentation on the Download page at http://www.rfxcom.com

Bert