How to get SAAB 95 steering remote to work with the Kenwood protocol

Project completed

PCB build completed

Measured in car (blue -cavity 1):

Vol- 1.253V

Vol+ 1.668V

Src 2.072V

Seek + 2.485V

Seek - 2.904V

Nxt 3.313V

No button 4.020V

Engine running gives same result

Part 1 of 4

Part 2 of 4

Part 3 of 4

the tiny PCB is finished

caps a bit bigger than hoped for

Current draw of 20mA makes for

about 0.14W to dissipate

12V or 14V -Vout 5V * 20mA

i.e.no heatsink needed

PCB in its enclosure

Power for PCB directly from car DIN connector

function measured min - max dec.

Vol- 1.253V 1,1 - 1,4 => 57 - 71

Vol+ 1.668V 1,5 - 1,8 => 77 - 92

Src 2.072V 1,9 - 2,2 => 97 - 112

Seek + 2.485V 2,3 - 2,6 => 118 - 133

Seek - 2.904V 2,7 - 3,1 => 138 - 159

Nxt 3.313V 3,2 - 3,5 => 164 - 179

if statements in code checks if ADC value is between min-max for button

Project not completed..

time to make PCB

(Part 3)

C code v5.0

Final version...?

hysteresis added