Equations
The PID Editor contains a reasonably powerful equation editor that allows you to manipulate the incoming data from an OBD device, Sensor, or other data input to the app
Contents
- 1 Functions that manipulate data
- 1.1 EWMAF(weight:value)
- 1.2 TAVG(seconds:value)
- 1.3 RAVG(value)
- 1.4 AVG(bucketSize:value)
- 1.5 TDLY(seconds:value)
- 1.6 RDLY(polls:value)
- 1.7 TOT(seconds:value)
- 1.8 SIN(value), COS(value) ,TAN(value)
- 1.9 LOG(value)
- 1.10 LOG10(value)
- 1.11 LOG1P(value)
- 1.12 INT(value)
- 1.13 SQRT(value)
- 1.14 ABS(value)
- 1.15 SIGNED(value)
- 1.16 BIT(value:bit)
- 1.17 LOOKUP({VALUE}:{DEFAULT}:{KEY1}{OPERATOR}{VALUE1}:{KEY2}{OPERATOR}{VALUE2}:…etc)
- 1.18 CLOSEST({VALUE}:{DEFAULT}:{KEY1}={VALUE1}....)
- 2 Functions that generate or retrieve data
Functions that manipulate data
The equation editor supports the following functions
EWMAF(weight:value)
- Exponentially weighted moving average filter - filter noisy signals here. 'weight' should be between 0(more smoothing) and 1(less smoothing)
TAVG(seconds:value)
- Timed average. This averages the incoming data for the configured amount of time (in seconds). Data older than the configured time is removed from being averaged
RAVG(value)
- Rolling average. This averages incoming values until it is reset. No values are removed from the average until it is reset.
AVG(bucketSize:value)
- Point average. This averages incoming values from a bucket of s set size. The bucket can be configured to average a set amount of values, so AVG(10,value) would average the last 10 values
TDLY(seconds:value)
- Time based delay - causes data to be delayed by 'seconds' amount before being returned. Returns 0 until data buffer is full
RDLY(polls:value)
- Read based delay - data is delayed by X polling loops before being returned
TOT(seconds:value)
- Totalizer function based upon difference from time/value
SIN(value), COS(value) ,TAN(value)
- Trigonometric functions are supported
LOG(value)
- Returns the natural logarithm (base e) of a value
LOG10(value)
- Returns the base 10 logarithm of a value
LOG1P(value)
- Returns the natural logarithm of the sum of the value and 1
INT(value)
- Converts the incoming number to an integer
SQRT(value)
- Returns the correctly rounded positive square root of a value.
ABS(value)
- Returns the absolute value of the number given
SIGNED(value)
- Treats the incoming value as 8bit signed
BIT(value:bit)
- Returns the bit specified at 'bit' from the 'value'. This function replaces the use of the {value:bit} notation
LOOKUP({VALUE}:{DEFAULT}:{KEY1}{OPERATOR}{VALUE1}:{KEY2}{OPERATOR}{VALUE2}:…etc)
Look up a value from a list of key/value pairs. Can be used to substitute values, reply with a text string, etc
Examples:
String, exact matching, returning a string:
LOOKUP(A::1=’moo’:2=’boo’)
Numeric, exact, with a default of 0 for no match:
LOOKUP(A:0:1=100:2=200:3=300)
Numeric, exact, with a default of the input value for no match:
LOOKUP(A:A:1=100:2=200:3=300)
Numeric, range matching – 0 to 3 = 4 and 4 to 5 = 7:
LOOKUP(A::0~3=4:4~5=7)
String, exact matching, returning a string, value is also returned into the PID. The value will be ‘5’ when A is 2, and 4 when A is 1 (the display will show boo and moo however):
LOOKUP(A::1=’moo’:2=’boo’)+3
Mixed matching with strings and numbers (Strings are shown on the display with numbers being passed through to the equation) exact, with a default of the input value for no match:
LOOKUP(A:A:1=100:2=200:3=’this is a test’)
CLOSEST({VALUE}:{DEFAULT}:{KEY1}={VALUE1}....)
Similar to the LOOKUP function, this returns the value which is numerically closest to the key
Examples:
Return 'low' when less than 128 and 'high' when near 255:
CLOSEST(A:A:1='low':255='high')
Functions that generate or retrieve data
RANDOM()
- Returns a random number between 0 and 1
BARO()
- Returns the barometric pressure from the android device or measured from the vehicle ECU if it supports it in psi
