Gems LDS4, Operation Manual, Page: 65 / 71

59 Appendix B: Example Sensor Calibrations
© 2009 General Engine Management Systems Ltd.
When using an analogue input and a potentiometer to get gear position from the gearbox directly,
it is necessary to use a function table on the raw A/D gear position value to produce a gear
position number (0 to 8) that can be used with a bit string sensor. To do this, note the raw A/D
value in each gear. Then create a function table with two entries for each gear; the first entry will
be the half way point between the current gear and the previous gear. The second entry will be
the half way point between the current gear and the next gear. This ensures that the function
table will only return a whole number between 0 and 8.
For example, consider a gear position setup with the following A/D values at each position:
Gear A/D Value
R 10
N 100
1 200
2 300
3 400
4 500
5 600
6 700
The function table would be configured as follows:
Function
Table Input
Function
Table Output
0 0
55 0
56 1
150 1
151 2
250 2
251 3
350 3
351 4
450 4
451 5
550 5
551 6
650 6
651 7
1024 7
The output of this function table is then used in a new output with a bit string sensor as discussed
at the start of this example.