[Ovmsdev] New Metric Units

Michael Balzer dexter at expeedo.de
Tue Nov 8 20:35:00 HKT 2022


Michael,

looks all good to me, once again nice find with the decode argument. 
Adding decode to the Value() call was only for symmetry IIRC, the main 
use was with GetValues() 
(https://docs.openvehicles.com/en/latest/userguide/scripting.html#ovmsmetrics).

Don't forget to test arrays, e.g. "v.t.pressure" & "v.t.temp".

Returning null for an undefined metric seems like a natural choice, but 
is a rather deep change, as for consistency not only the Duktape metrics 
API but also the Web UI metrics API would need to be changed 
accordingly. Unless you've got a real use case that needs that, we 
should be careful.

Regards,
Michael


Am 07.11.22 um 15:00 schrieb Michael Geddes:
> I have figured out a bunch of stuff and have implemented the 
> following: (having done away with needing AsFloatUnit)
>
> OvmsMetrics.Value( {metric} [, {decode}])
> OvmsMetrics.Value( {metric}, {unit} [,{decode}])
>
> It turns out that the [decode] flag wasn't working anyway (since the 
> function was being registered as only having 1 param)...
> This way it is still really 1 function.. but I check it the second 
> parameter is a 'boolean', and if not.. try the second form.
>
> OvmsMetrics.AsFloat( {metric} [,{unit}] )
>
> and add the function
>
> Ovms.Metrics.ValueUnit( {metric} [,{unit}])
> This prints the value and the unit.
>
> Here's a sample function and the output! This also shows the types of 
> the output.
>
> (function() {
>    x = OvmsMetrics.Value("xiq.v.trip.consumption");
>    print( (typeof x) + ": "+  x+"\n"  );
>    x = OvmsMetrics.Value("xiq.v.trip.consumption", false);
>    print( (typeof x) + ": "+  x +"\n" );
>    x =  OvmsMetrics.Value("xiq.v.trip.consumption","kmpkwh")
>    print( (typeof x) + ": "+ x +"\n");
>    x =  OvmsMetrics.Value("xiq.v.trip.consumption", "mipkwh", false)
>    print( (typeof x) + ": "+ x +"\n");
>    x =  OvmsMetrics.ValueUnit("xiq.v.trip.consumption")
>    print( (typeof x) + ": "+ x +"\n");
>    x =  OvmsMetrics.ValueUnit("xiq.v.trip.consumption","mipkwh")
>    print( (typeof x) + ": "+ x +"\n");
>    x =  OvmsMetrics.AsFloat("xiq.v.trip.consumption")
>    print( (typeof x) + ": "+ x +"\n");
>    x =  OvmsMetrics.AsFloat("xiq.v.trip.consumption","kmpkwh")
>    print( (typeof x) + ": "+ x +"\n");
> })();
>
> number: 17.0582
> string: 17.0582
> number: 5.86227
> string: 3.64264
> string: 17.0582kWh/100km
> string: 3.64264mi/kWh
> number: 17.0582
> number: 5.86227
>
>
> It still might be an idea to use 'null' as a return value if the 
> metrics is!IsDefined() but that would be changing the existing 
> behaviour slightly.
>
> //.ichael
>
> On Mon, 7 Nov 2022 at 08:12, Michael Geddes 
> <frog at bunyip.wheelycreek.net> wrote:
>
>     I've worked out what the decode flag is for and how it works, and
>     I think how optional params work.
>     I'm pretty sure I won't  need the 'AsFloatUnit' function; the unit
>     would be an option to AsFloat(); I'll know that soon.
>
>     The 'Value' function is more complicated because of the optional
>     decode bool. I guess I could add the Unit to the end of that.
>
>     ValueUnit could be still useful then to provide a 'Value + Unit'.
>
>     Question:  Is there a reason we shouldn't be returning with
>     duk_push_null   if the metric !IsDefined()  in both AsFloat() and
>     Value(metric,true) cases?
>
>     //.ichael
>
>     On Sun, 6 Nov 2022 at 11:22, Michael Geddes
>     <frog at bunyip.wheelycreek.net> wrote:
>
>         Right, so I've implemented some stuff that seems to work quite
>         well.
>
>         https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/pull/764
>         should be ready now after a couple of stupid mistakes slipped
>         through.   This absolutely needs somebody to review it please!
>         (There's a reason why I've converted some if()'s to switch() -
>         which is that it will be used in the follow-up commit).
>
>         The commit that will follow on from that it implements the new
>         Units: kWh/100km, km/kWh  and mi/kWh.
>
>         This is a summary of what I've implemented for scripting -
>         including showing the unit codes I have so far.  I've
>         considered a few things:
>           * Should some of the longer unit codes be shortened  (eg mi,
>         mins, m, ft, deg, perc)
>           * The unit codes could be much more regular and separated by
>         dots  eg:
>                 watthours -> w.h
>                 kwhp100km -> kw.h_100km or kw.h/100km
>                 miph ->  mi_h or mi/h  (or should it be mph).
>                 psi -> p_in.in <http://p_in.in> or p/in.in
>         <http://in.in> or lb_in.in <http://lb_in.in> (yes, slightly
>         weird, but predictable)
>
>         *OVMS# metric units*
>                   km : km
>                miles : M
>               meters : m
>                 feet : ft
>              celcius : °C
>           fahrenheit : °F
>                  kpa : kPa
>                   pa : Pa
>                  psi : psi
>                volts : V
>                 amps : A
>         amphours: Ah
>                   kw : kW
>                  kwh : kWh
>                watts : W
>         watthours: Wh
>              seconds : Sec
>              minutes : Min
>                hours : Hour
>                  utc : UTC
>              degrees : °
>                 kmph : km/h
>         miph: Mph
>         kmphps: km/h/s
>         miphps: Mph/s
>                 mpss : m/s²
>                  dbm : dBm
>                   sq : sq
>              percent : %
>                whpkm : Wh/km
>         whpmi: Wh/mi
>            kwhp100km : kWh/100km
>         kmpkwh: km/kWh
>         mipkwh: mi/kWh
>                   nm : Nm
>
>         *OVMS# metric unit mi*
>                miles : M
>              minutes : Min
>                 miph : Mph
>               miphps : Mph/s
>                whpmi : Wh/mi
>               mipkwh : mi/kWh
>
>         *OVMS# metric get xiq.v.trip.consumption
>         *17.0597kWh/100km
>         *OVMS# metric get xiq.v.trip.consumption kpkwh
>         *5.86177km/kWh
>         *OVMS# metric get xiq.v.trip.consumption mpkwh
>         *3.64233mi/kWh
>
>         *OVMS# metric set xiq.c.speed 5 miph
>         *Metric set
>         *OVMS# metric get xiq.c.speed
>         *8.04673km/h
>         *OVMS# metric get xiq.c.speed miph
>         *5Mph
>
>         And then in DukTape - there are some questions I have about
>         the implementation:
>         * Names of functions? Better ideas?
>         * Should ValueUnit output the units?
>         * In Value() there is the line   bool decode =
>         duk_opt_boolean(ctx, 1, true);
>             * What does 'decode' mean here?
>             * Do I need it for ValueUnit() ?
>
>         *
>         (function() {
>            print( OvmsMetrics.Value("xiq.v.trip.consumption"));
>            print("\n")
>            print( OvmsMetrics.ValueUnit("xiq.v.trip.consumption",""));
>            print("\n")
>            print(
>         OvmsMetrics.ValueUnit("xiq.v.trip.consumption","mipkwh"));
>            print("\n")
>
>            print(
>         OvmsMetrics.AsFloatUnit("xiq.v.trip.consumption","kmpkwh"));
>         })();*
>         --- Output ---
>         17.0597
>         17.0597kWh/100km
>         3.64233mi/kWh
>         5.86177
>         ------
>
>         The basic stuff all works - it's just quibbling over the
>         details.. but let's get them right!
>
>         //.ichael
>
>         On Sat, 5 Nov 2022 at 20:09, Michael Geddes
>         <frog at bunyip.wheelycreek.net> wrote:
>
>             Yeah - this was copied code from kia/kona and is what
>             triggered these ideas; I totally agree this shouldn't be
>             doubled up on.
>
>             I've got some commits centred round Metrics that I'll just
>             check over and push up ... and then I'll just have the
>             single xiq.v.trip.consumption metric (unless you have some
>             ideas for the namespace) which will be much neater.
>
>             If it's ok with you then I might do that unit conversion
>             proposal.
>             Would it ok if the unit specifications were the same as to
>             the programatic codes in ovms_metrics.h?
>             (kWh,   WattHours , MetersPSS )
>             I would probably add a command
>             metric units <spec>
>             to list all (matching) units and their associated Labels.
>
>             //.ichael
>
>             On Sat, 5 Nov 2022 at 18:48, Michael Balzer
>             <dexter at expeedo.de> wrote:
>
>                 Michael,
>
>                 adding unit conversion support to the shell and
>                 Duktape commands is a good idea.
>
>                 Metrics are not meant to provide a user interface,
>                 they should be defined to be efficient and non-redundant.
>
>                 Btw, metrics names also shall not use upper case
>                 characters, and shall only use "." as a separator.
>
>                 Regards,
>                 Michael
>
>
>                 Am 05.11.22 um 11:22 schrieb Michael Geddes:
>>                 Hi all,
>>                 Some of the code I copied from Kona/Kia code had both
>>                 kwh/100km and km/kwh metrics in the code as 'Other'.
>>                 Adding the various power consumption Units is not
>>                 particularly hard (I will have a pull-request soon) -
>>                 though the conversions between them all required some
>>                 thought!
>>                 ... but it also made me think these two metrics that
>>                 are (with the consumption units added) defined like
>>                 this:
>>                 m_v_trip_consumption1 =
>>                 MyMetrics.InitFloat("xiq.v.trip.consumption.KWh/100km",
>>                 10, 0, kWHP100K);
>>                 m_v_trip_consumption2 =
>>                 MyMetrics.InitFloat("xiq.v.trip.consumption.km/kWh
>>                 <http://xiq.v.trip.consumption.km/kWh>", 10, 0, kPkWH);
>>
>>                 These are effectively the same metric but in
>>                 different units!
>>                 I'm wondering if we would be better to have scripting
>>                 and Duktape support for converting metrics to
>>                 different unit!  This might be also quite useful for
>>                 those strange countries that insist on using miles as
>>                 a measurement.
>>
>>                 On top of the 'metric list' and 'metric set' we could
>>                 add a 'metric get' which gets a single value.. and
>>                 add unit support for get/set.
>>
>>                 I've also got a pull request that improves the
>>                 precision of the km<->mi conversions and factors it out.
>>
>>                 //.ichael
>>
>>                 _______________________________________________
>>                 OvmsDev mailing list
>>                 OvmsDev at lists.openvehicles.com
>>                 http://lists.openvehicles.com/mailman/listinfo/ovmsdev
>
>                 -- 
>                 Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
>                 Fon 02333 / 833 5735 * Handy 0176 / 206 989 26
>
>                 _______________________________________________
>                 OvmsDev mailing list
>                 OvmsDev at lists.openvehicles.com
>                 http://lists.openvehicles.com/mailman/listinfo/ovmsdev
>
>
> _______________________________________________
> OvmsDev mailing list
> OvmsDev at lists.openvehicles.com
> http://lists.openvehicles.com/mailman/listinfo/ovmsdev

-- 
Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
Fon 02333 / 833 5735 * Handy 0176 / 206 989 26

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openvehicles.com/pipermail/ovmsdev/attachments/20221108/1ecaa9e8/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 203 bytes
Desc: OpenPGP digital signature
URL: <http://lists.openvehicles.com/pipermail/ovmsdev/attachments/20221108/1ecaa9e8/attachment-0001.sig>


More information about the OvmsDev mailing list