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MegaShift GPIO Port and Pin Assignments

The GPIO processor has 25 free pins available for inputs and outputs (I/O) (not including the serial and CANbus communications pins), and 25 PCB I/O circuits available.

The microTCU™ pins are a bit different, see this link for information on the microTCU™ differences.

The default assignments for the GPIO pins are:

Click the links in the table itself for more information on specific functions/circuits.
Default
Function
Port/Pin
(I)nput or (O)utput
Default
Circuit
Assignment

(Ampseal Pin)
Alternate
Functions
Notes:
VSSPT0IVR1
(Amp 2)
<-none->Vehicle speed signal input, interrupt driven
ISSPT5IVR3
(Amp 14)
Engine speed (tachometer) inputInput shaft speed sensor or tach input, interrupt driven
PCPT2OPWM3
(Amp 33)
Spare Output3/Output9 (5.1xx code only)Line pressure control output on PWM2
TCCPT3OPWM2
(Amp 32)
<-none->Dedicated torque converter clutch control output on PWM3
Output1PE4OVB3
(Amp 23)
<-none->Dedicated shift solenoid output #1
Output2PM2OVB4
(Amp 35)
<-none->Dedicated shift solenoid output #2
Output3PT1OPWM4
(Amp 34)
<-none->Dedicated shift solenoid output #3
Shift Lever
Input1
(digital)
PAD00 *IEGT4
(build as GPI)
(Amp 26)
Voltage lever inputADC count for shift lever position input #1
Shift Lever
Input2
(digital)
PAD01 *IGPI2
(jumper at 25x2 header)
(Amp 6)
Output5ADC count for shift lever position input #2
Shift Lever
Input3
(digital)
PAD03 *IEGT3
(Amp 25)
Output6ADC count for shift lever position input #3
Paddle UPPT6IVR2
(build as digital input)
(Amp 15)
<-none->Digital on/off input for up-shifting
Paddle DOWNPAD06 *IGPI5
(Amp 4)
Voltage shifter buttonsOn/off input for down-shifting, but can be an ADC input
LED1PM4OGPO1
(Amp 10)
7-segment displayLow current output
LED2PM3OGPO2
(Amp 7)
7-segment displayLow current output
LED3PM5OGPO3
(Amp 8)
7-segment displayLow current output
LED4PB4OGPO4
(Amp 9)
7-segment displayLow current output
Brake SensePAD07IGPI4
(Amp 3)
<-none->Digital on/off input
non-CANbus MAP/TPS/MAFPAD05 *IEGT1
(Amp 24)
Report auxiliary variable voltage signal level as aux_volts (if using CANbus)ADC count
Line Pressure SensorPAD04 *IEGT2
(Amp 27)
Optional logging onlyADC count
Temperature SensorPAD02 *IGPI3
(Amp 30)
Optional logging onlyADC count
Speedo OutputPT4OPWM1
(Amp 31)
Spare 0utput0/Output8
4WD InputPE1IGPI1
(Amp 5)
shift table switching/Shift lever Input 4Digital on/off input for switching between shift table 1 and shift table 2
Spare Output1PT7
(Amp 2)
OVB1
(jumper at 25x2 header)
(Amp 11)
Output7User Spare Port, PWM, TCC, Shift Solenoid, or Selective Clutch.
Spare Output2PA0OVB2
(Amp 12)
Output4User Spare Port, PWM, TCC, Shift Solenoid, or Selective Clutch.

Pin PE0 and circuit VR4 are not assigned in the default builds (but these are available on the 25x2 header, of course).

The "OutputX" label (Output1, Output2, etc.) has been restricted to pins that can be used as shift solenoid outputs. These outputs have a user specified state for each gear to shift the transmission between gears. There are other types of outputs, of course, such as TCC, PC, speedo output signal, etc. but these are labeled differently.

"InputX" refers to manual shift lever position signal digital inputs. There are other types of inputs, of course, such as VSS, temperature, brake, etc. but these are labeled differently.

Spare Outputs are outputs that have multiple user configurable functions (including possible use as shift solenoid control outputs). See this web page for more details.

* The analog-digital converter pins PAD00 to PAD07 are also know as ADX, AD0X, etc., but are never referenced as PA00 or PA0 as there is an separate port A on the HCS12 processors.



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© 2014 Bruce Bowling and Al Grippo. All rights reserved. MegaSquirt® and MicroSquirt® are registered trademarks. This document is solely for the support of MegaSquirt® boards from Bowling and Grippo.