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cyipher
February 6th, 2014, 03:48 AM
If I reference off a voltage pid that has a resolution .1 in the calc.pid file is that resoultion show only in the scanner or does it round the number if i use that pid in a equasion? such as GM.ACPS has a true voltage of 2.55, this is rounded to 2.6 in the scanner, if i use GM.ACPS in an equasion such as ({GM.ACPS}*3)+7.35 is the answer gonna be 15 or 15.15?
joecar
February 6th, 2014, 07:56 AM
The .1 you see in the calc_pids.txt file is the number of decimal digits to display on the Char/Gauge (i.e. the display format)... it is not the resolution of the analog voltage read.
cyipher
February 6th, 2014, 09:07 AM
The .1 you see in the calc_pids.txt file is the number of decimal digits to display on the Char/Gauge (i.e. the display format)... it is not the resolution of the analog voltage read.

so since the acp pid is read in steps, (5V / 255 Steps) .02 voltage steps is what the analog voltage reads in? why in the scanner does acp and acps both read in volts, and one not read in steps? whats the point in the (RAW({GM.ACP})/51) and the ACPS pid then?
joecar
February 6th, 2014, 10:04 AM
Yes, correct, 5V in 256 steps (8-bit ADC) has a resolution of 0.02V.

RAW() gets the raw data for that pid (vs that pid's units-converted value).

Guess what 1/51 equals (0.02)...

so RAW({GM.ACP}) is the steps, and diving by 51 converts it to volts.
cyipher
February 6th, 2014, 10:42 AM
Yes, correct, 5V in 256 steps (8-bit ADC) has a resolution of 0.02V.

RAW() gets the raw data for that pid (vs that pid's units-converted value).

Guess what 1/51 equals (0.02)...

so RAW({GM.ACP}) is the steps, and diving by 51 converts it to volts.

But why when logging gm.acp (which should be the raw unit) do i see volts? there are 2 pids gm.acp (raw) and calc.acps (calculated voltage) both show volts in the logger.
joecar
February 6th, 2014, 10:46 AM
GM.ACP has units V so it will be displayed in V (regardless of its raw value).

CALC.ACPS also has units V... if you do rightclick->MoreInfo on this pid (on the PIDs tab) you can see it is defined from the raw value (steps) of GM.ACP.
cyipher
February 6th, 2014, 11:07 AM
GM.ACP has units V so it will be displayed in V (regardless of its raw value).

CALC.ACPS also has units V... if you do rightclick->MoreInfo on this pid (on the PIDs tab) you can see it is defined from the raw value (steps) of GM.ACP.

so why even have a acps pid then?
joecar
February 6th, 2014, 12:00 PM
I don't know... maybe GM.ACP might be converting to V incorrectly... IDK for sure.