Add "flow rate" calculation by measuring what arrives in the cup

[FabianSperrle]

• determine weight in the cup whenever we get a new weight measurement, divide by time since last measurement to get flow rate into the cup
• added a sliding window average over the last 10 measurements to get smoother output
• adjusted display template to show flow rate

[FabianSperrle]

In case this is well-received: would you also want flowrate (and weight) published via MQTT?

[LoQue90]

I'm not into the scale, need the space to the portafilter for the cup, so I can't judge any scale related features. But until now, anything that we measure or adjust is published to MQTT and is modified if possible through MQTT. So I would say, go for. :)

[FabianSperrle]

I'm not into the scale, need the space to the portafilter for the cup, so I can't judge any scale related features. But until now, anything that we measure or adjust is published to MQTT and is modified if possible through MQTT. So I would say, go for. :)

Until I buy a bottomless portafilter I just screwed off the spout to gain some space, otherwise it would be painful, yes...

[FabianSperrle]

Superseded by #450