On 10/25/2014 11:26 PM, Aurelien Jacobs wrote: > On Sat, Oct 25, 2014 at 10:43:11PM +0300, Janne Huttunen wrote:
>> Now, this measurement in case of my LCR meter consists of two >> independent "axes" that have their own MQ and unit, but still >> are parts of the same measurement. The device sends one such >> measurement as a single data packet, but the current driver >> exports the two parts as separate "channels" in two separate >> packets. This separates the parts from each other, which is >> not a good thing. It would be much better to export a complete >> measurement to the client program as a single packet. >> >> The problem is that I don't know if that is currently possible. >> It is easy to put data from multiple channels into one packet, >> but the problem is that in this case the different channels >> have different MQs and units. Is there currently some way that >> would allow sending a packet that contains multiple measurements >> with independent MQs and units each? > > No, unfortunatly it is not currently possible. > I agree with you about this problem, and IMHO, it would be nice > if we could output simultaneously several MQs on a single channel. > This would also benefit PPS which can report both V and A for each > channel. > If you have a concrete proposition to go in this direction, I > would like to here the opinion of other developpers. The need for this has come up before, in the context of logic + analog data that refers to the same time period, e.g. input and output of some ADC. The frontend would need some way to sync up the two streams. And indeed, the PPS example is a good one. Some of these devices allow for grabbing voltage and current measurements at the same time from the internal measurement averages, but sigrok doesn't permit reporting them as synced measurements. There are several options. - Extend the sigrok packet to take multiple payloads, for example logic + analog, analog + analog. This could be done by simple adding a field to it (num_payloads). These payloads are then to be considered in sync. - Add a meta packet type for something like a "mark" or "sync", and have subsequent packets refer to it with an extra field, indicating the point in the stream(s) where they sync up. - Extend the analog packet to be able to take multiple MQ/unit/data sets. However this leaves the logic+analog case without a solution. Probably more ways to do this that I haven't thought of. I'd like to hear Uwe and Martin's thoughts on this; whatever solution we come up with should translate easily into their V3 file/streaming format. >> 4. Floating point representation [...] > Many thoughts yes, since a long time, but no implementation: > http://sigrok.org/wiki/High_precision_analog Indeed. This is a lot of work, and needs somebody to own it, and drive the implementation of this. -- Bert Vermeulen [email protected] email/xmpp ------------------------------------------------------------------------------ _______________________________________________ sigrok-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sigrok-devel
