Page about a small addon board with AT2313 microcontroller

The board was originally designed to enable 135-cranktooth InputTrigger support for audi 5cyl engines. This explains the name, but the HW is not restricted to this job.

Note that this board is not needed for that purpose, because of the InputTrigger/AudiTrigger solution.


First version of a small addon board (with AT2313 and two LM1815 chips) is being designed to eat signal directly from stock sensors.


With help from CAM SYNK, it will feed suitable output signal for the mainboard. There are some unused pins available for e.g. frequency input to PWM output conversion or other purposes. Board can be adapted to work with different setups too.

make real circuit from the PCB

The PCB is very nice, but I guess we should order components together.


C1,C2 22pF 1206
C3,C4 100n 1206
C5,C9 --
C6,C10 --
C7,C11 --
C8,C12 --
C13 10u electrolytic
C15,C16 -- pwm output
R1,R5 150K 0805
R2,R6 5.6K 0805
R3,R7 1.6M 0805
R4,R8 18K 0805
R9,R10 2.2K 0805
R11,R12 1K 0805 (?)
R15 -- reset pullup
R16 -- pwm output
R17 -- pwm output
D1,D2,D3,D4 3v9 SOD80C zener
IC1 AT90S2313S
IC3,IC4 LM1815M
Q1 4Mhz X-tal
JP1 2x3 pin header
JP2 2x5 pin header