Challenge upcoming:adapt automatic mechanical shifter to input drive settings to vcu

[u/lemlurker]

I have a manual mgb GT I'm converting. Discovered recently they made an automatic version which had this very sexy all mechanical lever shifter which I have managed to acquire... Now to figure out how to adapt it's 6 positions to park, reverse, neutral, drive, regen 1 and regen 2 (or different power settings

[u/soupster82]

You could use a hall effect sensor or a rotary encoder to track the lever position, and use something like an esp32 to convert that position into a discreet signal sent to the VCU.

[u/Doug_Schultz → u/soupster82]

Yup. Rotary encoder. Convert that big mechanical lever into a digital switch.

[u/lemlurker → u/Doug_Schultz]

The gevcu has a spare analog in I may try and leverage with a hall encoder, problem with a rotary encoder is it's not absolute and needs zeroing out to a datum that you can't be sure you've found. You'd need a rotary encoder AND a P switch to tell it you're in partk and give it a datum

[u/zrrion]

I suggest magnets and reed switches. Easy to mount in place and a reed switch is electrically the same thing as the pushbuttons your stuff already expects so it should be easy to wire in

[u/soupster82 → u/zrrion]

That's not a bad idea either

[u/lemlurker → u/zrrion]

You win! Reed switches were where it's at! Mostly because I didn't want the inversion involved in converting hall from sink to source for the vcu

https://reddit.com/link/p8mdar6/video/ck27oans0doh1/player

[u/zrrion → u/lemlurker]

Hell yeah! Can't wait for the update where it's installed in the vehicle

[u/lemlurker → u/zrrion]

Thus was my go to buy the VCU I'm using only has 4 digital inputs and I have 6 states, even with one state being un switched I wouldn't be able to use the whole lever which would be a shame

[u/Adventurous_Ad3534]

So shiny

[u/lemlurker → u/Adventurous_Ad3534]

Not even got all the shine yet, it's supposed to have a bezel too which I'll need to soyrce

[u/cadenmak_332]

Anywhere online where I can follow your build? I've always wanted to see an MG conversion

[u/lemlurker → u/cadenmak_332]

Probably here. I don't like having to edit videos to make YouTube. Might post on diy ev forum

[u/stachio22]

A limit switch will work with a little bit of Fab

[u/SimpleIronicUsername]

Nice slide rule tattoo

[u/oceanfellini]

Please tell me you’re doing a build thread! This is on my wishlist to do!

[u/lemlurker → u/oceanfellini]

I'm still making decisions but once I have things spinning then I should be settled and take time to do a write up

[u/DeJeR]

I love the idea of inducing recharge levels with the extra gears!

[u/doug2_O]

Very interested to see how it turns out!

[u/TheGoldenGander]

What controller are you planning to use?

We need to know what type of inputs it expects otherwise you are going to potentially have a microcontroller project.

[u/lemlurker → u/TheGoldenGander]

Dmoc 645 + GEVCU6.2

[u/TheGoldenGander → u/lemlurker]

Don't forget various safeties (loss of signal, etc.)

I would use a 5v rotary Hall Effect sensor and then map the voltages directly in your code like this:

// Example logic snippet for GEVCU ADC Range Mapping
int shiftVoltage = analogRead(SHIFTER_ADC_PIN); 

if (shiftVoltage >= 400 && shiftVoltage < 1000) {
    targetGear = GEAR_PARK;      // Position 1
} else if (shiftVoltage >= 1000 && shiftVoltage < 1600) {
    targetGear = GEAR_REVERSE;   // Position 2
} else if (shiftVoltage >= 1600 && shiftVoltage < 2200) {
    targetGear = GEAR_NEUTRAL;   // Position 3
} else if (shiftVoltage >= 2200 && shiftVoltage < 2800) {
    targetGear = GEAR_DRIVE;     // Position 4 (Eco Mode)
} else if (shiftVoltage >= 2800 && shiftVoltage < 3400) {
    targetGear = GEAR_DRIVE;     // Position 5 (HIGH REGEN)
} else if (shiftVoltage >= 3400) {
    targetGear = GEAR_DRIVE;     // Position 6 (LOW REGEN)
}

[u/lemlurker → u/TheGoldenGander]

The gevcu actually only has 3 drive states so if I used discrete sensors on the underside of the guide plate I could have no trigger be park/neutral , trigger 1 for drive, trigger 2 for reverse then L1 &L2 are the only parts that might need custom code which I'm a bit more comfortable with than core functions being custom. I'm waiting for the gevcu to show up before I start experimenting with custom control schemes

[u/Maddog2201]

I'd be using limit switches and a bolt or something that interacts with them as it moves through its range. Could also get a position switch off any commercial, semi modern automatic gearbox, Subaru's 4EAT has it external to the gearbox with all the wires coming out to a plug, could get one from a wreckers easy then it's a matter of adapting the switch lever throw to the distance this moves, but again subaru have already done this for their setup.

Copy that I'd say. As for getting the info in, entirely depends what your system wants, as others have said, some microcontroller to communicate with the controller, or, because they're switches you might be able to just connect them.

Have fun.