Quote:
Would this be a good point to talk about hooking up Marcus' project to something like a Jim Stim?
I am a firm believer in crawl, stand, walk, run development. The Jim-Stim and an adhoc system would be great for proof of concept. Maybe use a real VR input Aka the RX-7 or Miata instead of the JimStim for those circuits. Full functionality of firmware is not necessary at this point, but a full knowledge of what options you intend to have available would be ideal. There will always be feature-creep. Plan for that somehow. Then I would go right to PCB development. That would be the time to determine connectors which may end up as a 2x"x" dual row header that can be wired to the connector to the outside world to start.
I know a lot of other engineers who go from thought to PCB, skipping the breadboard stage. This is costly and adds time to the development IMO.
Thinking for just a few minutes, if I were to develop a new DIY controller I would plan for......
8 analog inputs: 2 VR/HE, dedicated 12V sense input (not the same as the 12V power);Wideband input, coolant temp, oil pressure(for fuel pump shut off control?), fuel pressure, others?.
8 injector outputs (full sequential) switched ground
8 coil outputs (COP) switched ground
8 assignable switched outputs (fan, tach, variable cam, variable intake volume, EGR valve, purge valve etc) switched ground
4 PWM outputs (IAC, Boost, Cam, fuel pump regulation? etc)
4 analog outputs, alternator
Fuel Pump relay output
Many ground wires, ideally 1 for each Input and "n" for outputs)
Communications lines (USB, Bluetooth, Wi-Fi, CAN)
Probably others too. This is the quick list. Anything less would really limit the marketability IMO. Look at the MS3 capability and don't offer any less. At least with a CAN output, you could expand...... Try to offer these features so that no item requires changing components on the PCB's. And that the use of any 1 feature does not eliminate any the use of other feature, at lease in hardware. Analog inputs using various brand OEM sensors without changing board level components might be a challenge.
_________________
Chuck.
“Any suspension will work if you don’t let it.” - Colin Chapman
Visit my ongoing MGB Rustoration log:
over HEREOr my Wankel powered Locost log :
over HEREAnd don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766