[Tinyos-2.0wg] (no subject)

[Jan Hauer]

> - SID interfaces and HAL effects (Jan)

Unfortunately I will not make it for the telephone conference tonight.
Here is a short summary of my opinion to the issue: currently the HAL
(it's the HAL2) of the ADC provides Read, but cannot meet the
requirements of this interface ("Any value contained in a simple type
MUST be left shifted so that it covers as much of the type's range as
possible", TEP 114). Shifting should be done by the component that
configures the ADC and knows the actual value range, which is usually
the sensor component. Still, providing Read by the HAL2 is very
convenient because there is a lot of redundant code in the sensor
wrappers otherwise (mapping the chip-specific ADC interface to Read).
I suggest to provide Read by the ADC without any constraints on the
content of the data. Since this is different to what the SID TEP
proposes we should make it clear by making the HAL2 representation
(AdcReadClientC) private (i.e. AdcReadClientP) and let sensor
components be the "public" components on top, have an extra section in
the ADC/SID? TEP about it and make it clear in the ADC component's
signatures (e.g. "provides Read as ReadRaw").

Jan