For discussion of Speeduino compatible boards designed / built by other members of the forum and for guidance around making such a board
So here I am, designing my own standalone board in Easyeda, running into some questions.

I have designed an "ignition only" standalone board in the past for Citroen 2cv but it can do 8 cil. on distibutor. It ran on a atmega 328. I used the same boards for injection and sold about a hundred or so to other 2cv drivers.

I also had my own software running on them, take a look at my youtube channel www2cv4x4nl

Now I want to make my own standalone ignition and injection board with a Mega 2560, So I can run my own software, programmed in BASCOM or run speeduino.

Now my questions, is there a pinout for the Atmega 2560 , or does it work with an .ini file. I can't find out how it works in speeduino.

And I want some D-packed mosfets for the injection, which one can I use and is there a schematic?

Also I am still in doubt which connector to use, any reccommendations??

Some Key features.

Mega2560 on board
4 IGTB ignition drivers (yes it is possible on the same board with a snubber circuit).
4 mosfet injection drivers
NCV1124 vr IC (yes it works, never missed a single beat) made over 100 boards already with it,.
Boost (yes my Citroen 2cv engines run turbo's form a Smart car.)
map baro
rs232 communication (works for me and all my users)

if there is still place left there will come more features.

Where it is possible I use smd 1206 components, which you still can solder (I can do it you can do it too lol).

I'm learning Easyeda at the moment, so I can order my boards at JLCPCB.

Here my attempt so far.
Knipsel.JPG (100.4 KiB) Viewed 1657 times
Knipsel-2.JPG (71.44 KiB) Viewed 1657 times

n.b. The IGTB and voltage regulator will be lying flat on the board in a heatsink. This works for my.

Here some pictures of my standalon ignition 1-2-spark.
Knipsel2.JPG (139.29 KiB) Viewed 1657 times
1-2-spark (1).JPG
1-2-spark (1).JPG (214.45 KiB) Viewed 1656 times
1-2-spark.JPG (313.15 KiB) Viewed 1657 times
#61716 (schematics) (firmware)

Big green button. Download the zip files, and have a good browse. :) If you download Kicad, you will be able to open 'v0.4.3d.kicad_pro' in this folder. 'Hardware-main\v0.4\THT\Latest' Some insight into Kicad ... ls/Windows

If you design a board that uses an existing pinout, then it will be easier.
I don't think so.
1. I want to make a standalone board where routes from vr ic to mega are as short as possible. Longer routes as by a piggyback arduino 2560 are a pain in the ass, being noisy as hell. I did research on this subject belief me.. (This is why a piggyback 2560board never will work perfect in my eyes).
2. I want just 1 board, with build in IGTB,s driving my old school TCI coil/coils. I don,t want a second board to drive my coils. I think there are still a lot of cars out driving the old fashioned TCI coils.
3. I can make a board to my needs, not to others needs.
4. I can run my own software (when I want), where I have 3xtable-switch, multi spark events at startup etc. And just 1 tooth at my crank at 45 degrees before tdc. For a 2cv with 1 ignition event per crank rotation this is Spot on.
So it took me quit a bit of time but here I have a pinout of Speeduino referring to the Mega2560 chip.

I think there are still a few pins left like fan etc. or pins which are wrong. Please feel free to correct my sheet.

Please take a look and shoot.

However, I don't understand why I have to do this (making this sheet) and why this is never done by somebody, or am I the only fool in town..

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That list can only apply to one board version. Different boards use different pinouts, and why you must select the board version in TunerStudio. The default pinouts are listed in the code download under the Speeduino folder, in the init.ino file. An example is below, of the v0.4-series pin mapping section under case 3. Note in TunerStudio, you can change many pin functions to other chores, e.g., Fuel Pump is default pin 45, but can be changed to another output such as pin 4, the default for VVT (common output swap):
Code: Select all
case 3:
      //Pin mappings as per the v0.4 shield
      pinInjector1 = 8; //Output pin injector 1 is on
      pinInjector2 = 9; //Output pin injector 2 is on
      pinInjector3 = 10; //Output pin injector 3 is on
      pinInjector4 = 11; //Output pin injector 4 is on
      pinInjector5 = 12; //Output pin injector 5 is on
      pinInjector6 = 50; //CAUTION: Uses the same as Coil 4 below. 
      pinCoil1 = 40; //Pin for coil 1
      pinCoil2 = 38; //Pin for coil 2
      pinCoil3 = 52; //Pin for coil 3
      pinCoil4 = 50; //Pin for coil 4
      pinCoil5 = 34; //Pin for coil 5 PLACEHOLDER value for now
      pinTrigger = 19; //The CAS pin
      pinTrigger2 = 18; //The Cam Sensor pin
      pinTrigger3 = 3; //The Cam sensor 2 pin
      pinTPS = A2;//TPS input pin
      pinMAP = A3; //MAP sensor pin
      pinIAT = A0; //IAT sensor pin
      pinCLT = A1; //CLS sensor pin
      pinO2 = A8; //O2 Sensor pin
      pinBat = A4; //Battery reference voltage pin
      pinDisplayReset = 48; // OLED reset pin
      pinTachOut = 49; //Tacho output pin  (Goes to ULN2803)
      pinIdle1 = 5; //Single wire idle control
      pinIdle2 = 6; //2 wire idle control
      pinBoost = 7; //Boost control
      pinVVT_1 = 4; //Default VVT output
      pinVVT_2 = 48; //Default VVT2 output
      pinFuelPump = 45; //Fuel pump output  (Goes to ULN2803)
      pinStepperDir = 16; //Direction pin  for DRV8825 driver
      pinStepperStep = 17; //Step pin for DRV8825 driver
      pinStepperEnable = 24; //Enable pin for DRV8825
      pinFan = 47; //Pin for the fan output (Goes to ULN2803)
      pinLaunch = 51; //Can be overwritten below
      pinFlex = 2; // Flex sensor (Must be external interrupt enabled)
      pinResetControl = 43; //Reset control output
      pinBaro = A5;
      pinVSS = 20;
      pinWMIEmpty = 46;
      pinWMIIndicator = 44;
      pinWMIEnabled = 42;
So here is my Easyeda schematic speeduino 2560 board and the latest excel pinout.. With a good example of the Arduino mega2560 pimnout..
Feel free to comment.

I'm still in doubt which connector to use.. between my board and wire loom.

Also still in doubt to use pre wired connectors, however you need to adjust them anyway, I always use shielded wires for my VR-sensors and IAT, CLT, TPS, A.S.O.
EASYEDA SCHEMATIC SPEEDUINO ATMEGA 2560.png (149.04 KiB) Viewed 1249 times
arduino_mega_2560_pinout.png (934.85 KiB) Viewed 1249 times
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Last edited by LPGo on Tue Mar 14, 2023 8:35 pm, edited 1 time in total.
I havn't checked, but ensure flex, boost, idle, and any others requiring it, are on pwm pins. nothing to stop you putting FP on pwm pin to future proof a little.

Does stepper require enable EN
By dazq
LPG2CV wrote: Mon Mar 13, 2023 9:15 pm I havn't checked, but ensure flex, boost, idle, and any others requiring it, are on pwm pins. nothing to stop you putting FP on pwm pin to future proof a little.

Does stepper require enable EN
That's not quite true , sorry , no need for pwm pins.

The only pins that matter are the crank and can triggers and the flex fuel input.
These must be on interrupt supported pins .on the mega these choices are limited.

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