Hi,
Yes that's a very interesting and useful spreadsheet, but I think the "Protocol" column might be a little misleading. Of course it's a complex issue and some sensors may use (or be available in) more than one format. In particular, I believe (from the Sandaysoft forum) that Davis use a "legacy" version of the SRT31. Furthermore, a simple address discrepancy may prevent a sensor being recognised, or a particular "library" might use the bus in an "unexpected" way.
"One Wire" is normally considered as a very specific protocol developed by Dallas/Maxim to carry bi-directional data and (optionally) power on a single wire. Actually of course, a second "Earth Return" wire is normally required to complete the circuit. It uses ingenious (and complex) "arbitration" methods to allow multiple devices (sensors) to be identified and read/controlled over the single pin/conductor.
Some "dumb" sensors may periodically "spew out" a stream of serial data on a single pin/conductor, but this would not normally be defined as "One Wire". Similarly, the second group of three sensors in your table appear to have "Data" and "Clock" pins and thus are unlikely to be "One Wire". A very common data interface is called "SPI" (Serial Peripheral Interface) but this usually has separate "Clock", "Data Out", and "Data In" (sometimes an "Enable" pin as well). So I'm not sure what the "Clock" plus bidirectional "Data" line used by Sensiron might be called.
Similarly, the I2C bus (developed by Philips) would normally be identified by the specific pin names SDA (Serial DAta) and SCL (Serial CLock). But a few manufacturers do use the I2C protocol but choose to "hide" its origin, due to possible trademark/copyright issues, or simply "pride" (the Philips patent will have expired many years ago). So I'm also "suspicious" about the protocol name used for the SHT10-15 (also one is marked STH) but I haven't checked their data sheets.
Cheers, Alan.
Yes that's a very interesting and useful spreadsheet, but I think the "Protocol" column might be a little misleading. Of course it's a complex issue and some sensors may use (or be available in) more than one format. In particular, I believe (from the Sandaysoft forum) that Davis use a "legacy" version of the SRT31. Furthermore, a simple address discrepancy may prevent a sensor being recognised, or a particular "library" might use the bus in an "unexpected" way.
"One Wire" is normally considered as a very specific protocol developed by Dallas/Maxim to carry bi-directional data and (optionally) power on a single wire. Actually of course, a second "Earth Return" wire is normally required to complete the circuit. It uses ingenious (and complex) "arbitration" methods to allow multiple devices (sensors) to be identified and read/controlled over the single pin/conductor.
Some "dumb" sensors may periodically "spew out" a stream of serial data on a single pin/conductor, but this would not normally be defined as "One Wire". Similarly, the second group of three sensors in your table appear to have "Data" and "Clock" pins and thus are unlikely to be "One Wire". A very common data interface is called "SPI" (Serial Peripheral Interface) but this usually has separate "Clock", "Data Out", and "Data In" (sometimes an "Enable" pin as well). So I'm not sure what the "Clock" plus bidirectional "Data" line used by Sensiron might be called.
Similarly, the I2C bus (developed by Philips) would normally be identified by the specific pin names SDA (Serial DAta) and SCL (Serial CLock). But a few manufacturers do use the I2C protocol but choose to "hide" its origin, due to possible trademark/copyright issues, or simply "pride" (the Philips patent will have expired many years ago). So I'm also "suspicious" about the protocol name used for the SHT10-15 (also one is marked STH) but I haven't checked their data sheets.
Cheers, Alan.