Custom BCMs, thoughts and opinions.

[Cus]

I'm putting serious legwork into doing plug-and-play-ish BCMs for NA6s (and probably NA8s), and further down the track NBs and other old cars. (BCM being Body Control Module, aka "the computer that runs everything", interior lights, central locking, and 'stuff')

Why would I bother with this at all? Because it makes the car that little bit nicer to live with. After driving a modern car for a while, you get used to things like the interior lights staying on after closing the door at night time.

To give you an idea of the things that currently work:
- I've converted my interior lights to LEDs, and added more to the A-Pillar so you can actually see inside the cabin at night time
- Different light brigthness for 'door' and 'on' modes, with the nice light fade in/out (I went overboard, 'on' is way too bright most of the time)
- Keyless power windows, with auto up/down.
- Central locking (no clicker, I don't personally have one, no reason it wouldn't work with one though)
- Automatic-Up windows - The windows go up when I lock the car (yes, it's amazing)

Things in the pipe-line:
- Boot light & electronic boot release
- auto DRL control, or parkers, or both; ie, start the car and the parkers (or DRLs) come on, turn the car off and so do the lights.
- Windows put themselves down a bit when you open the door so you don't have to slam the doors with a hard top on. (then back up again when you close the door)
- "Lockable" windows - disable the buttons and/or the auto-window activities (good if want to lock the car with the windows down a bit in summer)
- NA 'eye control', like the sleepy-eye mod, but intelligenter.

Things way down the track:
- Bluetooth control - this will be harder to implement from a 'power' point of view, as cool as it would be to put your windows down from 10 feet away with an app on your phone, bluetooth uses a fair amount of power doing nothing (ie: if it's not a daily driver, you'll need to jump-start the car a lot, which nobody wants to do)
- Immobiliser sequence + relay output (eg: to disable the fuel pump) so unless both doors are closed, the passenger light is on and you're holding 'up' on the driver's side window, the car won't start. (or whatever you come up with, these would be per-customer)

Initially I was going to use non-automotive components (they're much, much cheaper) but the prototype in my car does weird things sometimes - if it's parked in the sun on a hot day, the passenger window stops working until the A/C has been running for 15 minutes, then it cools down and works again - This is why I'm looking at the auto-spec components (they're rated to 150deg C instead of 80ish) I'm not going to release a product that annoys me.

Looking at all Automotive Spec components for a "full stack" of features, the parts alone is going to be about $250. That's not including 'incidentals': wire, shrink wrap, connectors, etc. (maybe another $100) or 'accessories': central locking actuators, boot release, or A-Pillar LEDs- so a BCM would be $350 before it's even been assembled, more by the time it's been assembled, tested and had a firmware flashed to it, more again if you need all of the accessories to go with it (eg; lots of us already have central locking actuators).

So, on to the questions:

Is this something people would actually be interested in? The need for high-temp parts pushes the cost up way more than I expected.

I'm guessing not everyone is going to want all of the features. Which features would you want? (Do I make a couple of options and mass produce them, or do all custom orders? basically the only option you have to have would be the interior light functions)

In terms of things that need accessories; would you like the option of getting them with the kit (ie; A-Pillar LEDs, central locking actuators, etc)? or are you happy to source your own?

Would you rather install it yourself, or hand your car over for a day to have it installed? At present there's only a couple of OEM wires that need to be cut, I'm trying to keep everything as plug-and-play with the OEM wiring loom as possible.

What else would you like a BCM to do?


- Cus

[droo]

Just refer to mine Lucas :-P
Having done the serious legwork for mine, the result *is* amazing.
As an aside, the single biggest turnoff that would scare folk from wanting one is the install process of the wiring loom.It frankly is massive.
If you laid all the wiring for my project end to end, it wouldn't work any more.


With that out of the way, you would want:

• Smart indicator control (one touch 3 flash) - once you have this, you miss it when it's gone.
• Indicators that physically stop their clicking noise when stopped at traffic lights with indicators on after 10 flashes.
• Lighting control (independent parker light,motor up/down and headlight control) in fail secure mode so if the controller or it's wiring fails, the existing functions will work uninterrupted from the dash instrument switches.
• Independent head light left/right pop up control would be cool for "winking"
• Independent left/right door lock control - not remotely essential but still cool.
• Temperature sensing cabin to autodrop the windows a few cm when the interior reaches 40c then raises up when below 35c
• Rain sensing windscreen for wiper control and to raise previously temperature autodropped windows
• Speed sensitive intermittant wiper control.
• Adjustable ambient cabin lighting control.

While you're going this far you'd want an Ambient lighting sensor: - So when it's dark,this is to control:

• Door flood lights
• Door open side lights for traffic notification
• Boot / engine bay lighting control
• Disarming the car will enable the parklights, headlight pop up and headlights for "leaving home" operation leaving the lights on for 20-30 seconds.

Arming the car will disable the the parklights/headlights (if recently disarmed) for "coming home" operation.
Either switching the parklights/headlights off immediately or after a preset/adjustable time period 0-30 seconds after.
Having this controller will 'optimise' your battery usage so it's not draining the car during daylight operation.
Auto parklights and auto headlights in subdued weather/sunset - mine has the provision, but haven't coded it yet.
(I have this all on mine the past 8-9 months)


To use a single controller, all the stuff up until the "things in the pipeline" are doable on a mega2560
Things i wanted but began to run out of IO pins on my controller were temp sense to drop the windows an inch when the cabin got hot in summer.
Windows that wind up when locking the car (had this on my first version but haven't yet coded on the current version.)


One thing tho, as far as a BCM is concerned, will put many many (all?) people off a purchase is the *massive* wiring loom you'd need to create. Physically locating this safely and out of harms way is a prick.. Had to put mine UNDER the drivers seat.. WIshing i had it on the firewall behind the driver's seat just for convenience if i needed access to it, but aside from a single one hour fix the last 8 months, it's been maintenance free since i completed it in august last year. Also, you learn how sh*t electrical connectors are and that 30 hours of "software" troubleshooting can be fixed by simply finding one of the 'reliable' multi-use hardware connectors is not remotely as multi use at it was advertised.. *arghgghgh*



It works really modernises the roadster experience a lot.
Everyone should have window drop on their door opening!

[Rolley]

While you're both together in one thread I have questions!

I have followed both of your threads on BCM and lighting systems and am frankly blown away with what you are both doing and would like to give it a go.

When I was working in the trade I was always a dealer mechanic so building from scratch was never something I dealt with, it was diagnose, remove and replace...
For my cars I have built circuits for window timers also some tinkering with relay based pop-up control but this is all just basic auto-electrics, not a patch on the electronic controls you guys are building.

So what is the best/easiest/not so overwhelming way to get into this sort of electronic module construction and programming as a hobby? Are there project kits and websites or forums you could recommend?

Cus what would the end price be for your proposed kit?

[Cus]

Droo, You're a mad-man!

To keep the wiring loom down in size I'd skip over things like independent exterior light controls. I do like the sequence your car plays out when you lock/unlock the car, but it's what your car does! (and it would increase the size of the loom exponentially)

I'd like to leave the "must not fail" items alone - headlights and indicators for example, especially if I'm doing it as a kit. I really don't want a phone call that goes "i installed the kit, then my passenger opened the door, the headlights turned on, and now the car's on fire and my fish is dead"

For the "allowed-to-fail" items I'd like to be able make it so the kit can be unplugged and the OEM plugs put back so it can be bypassed on the side of the road if need be.

With that out of the way, you would want:

• Smart indicator control (one touch 3 flash) - once you have this, you miss it when it's gone. - not for me personally (i like to blinker "thanks" to trucks which you can't do with soft-touch). but it's a good idea and everyone else on the planet would probably like it
• Indicators that physically stop their clicking noise when stopped at traffic lights with indicators on after 10 flashes. - this means no more flasher-can, gets into the "must not fail" items above
• Lighting control (independent parker light,motor up/down and headlight control) in fail secure mode so if the controller or it's wiring fails, the existing functions will work uninterrupted from the dash instrument switches.- way too much wiring for a kit - well, independant light up/down would be cool, but we're playing with a lot of "must-not-fail" items, possibly doable as an installed kit, not a diy install kit.
• Independent head light left/right pop up control would be cool for "winking" - with variable speed, because yolo
• Independent left/right door lock control - not remotely essential but still cool. - my magna used to do this, unlock once opened just one door, unlock twice unlocked all of them, even with the key
• Temperature sensing cabin to autodrop the windows a few cm when the interior reaches 40c then raises up when below 35c - yes!
• Rain sensing windscreen for wiper control and to raise previously temperature autodropped windows - i need to work out howto rain-sense reliably - rolly, how do modern cars do it?
• Speed sensitive intermittant wiper control.- should be petty easy, just need to have something that allows adjustment of the speed, there's already a 'trigger once' wire in the car
• Adjustable ambient cabin lighting control.- also should be pretty easy, voltage divider and piggyback off the ashtray light into an analog in

Some kind of location-awareness would also be cool, but I think that'd need to be an addon type module (for the courtesy headlights and stuff)

So what is the best/easiest/not so overwhelming way to get into this sort of electronic module construction and programming as a hobby? Are there project kits and websites or forums you could recommend?

"It's easy!" -or- "Any sufficiently advanced technology is indistinguishable from magic" - I actually used your window timer circuit for my car, but instead of discharging capacitors, the controller checks if someone's pressing the window button, then turns the relay on. (my window buttons don't actually control the windows, the arduino checks them and then fires relays based on what it thinks needs to happen - instead of switching 12V at a few Amps, they're switching 5V at a few mA, they should last forever now)

First off, we're using "arduino" boards - we're not really, arduino is a brand name - we're using the "AC Cola" version, but unlike AC Cola, the knockoff boards use exactly the same chips (ATMega2560 or ATMega328) but cost $5 - $10 a pop instead of $40 or $50. But we call them arduinos for the same reason everyone calls brown fizzy sugar-water "coke", it's a common name and people know what you're talking about.

hardware:
- GOOD multimeter, GOOD soldering iron, GOOD wire strippers. not the best ones money can buy, but don't cheap-out, these will be your main tools, and you will use them every time you play electronics.
- a pen and lots of paper.
- ebay.com.au for the hardware starting out, an "Arduino Mega" is $10 from china, an "Arduino Nano" is $5. There is (or was) a "sainsmart" kit for about $80 that comes with an arduino mega, breadboard and some random "bits" to get you started building things. arduinos have "shields" for lots of things (basically piggy-back boards) - droo and I don't use them, but for starting out you can get some good pre-built circuits for a few dollars.
- places like jaycar will sell arduino clone boards (freetronics), but they're effin expensive, i purchased one because i wanted a nano in a hurry. I've since bought 5 more nanos for half the price from ebay. basically, avoid bricks-and-mortar shops unless you've got to get rid of a bunch of cash for tax purposes.
- mouser, element14 and digikey for the hardware once you've made something you want to last. more expensive than ebay, but also you can get items rated to higher operating temps, and they're "real" chips instead of china-clones.

software:
- arduino.cc download and install the Arduino IDE (Integrated Development Environment - you write the code, compile the code and upload the code all in one program) There are standalone tools you can use, but even I, master of doing things the hard way, use the Arduino IDE.

basic knowledge:
- know how to read a circuit diagram. you don't need to fully comprehend what the circuit does, you just need to be able to identify the components.
- the built-in tutorials with the Arduino IDE (https://www.arduino.cc/en/Tutorial/BuiltInExamples) will get you started programming. programming is not hard unless you want it to be.
- forums.arduino.cc
- google searches, results that take you to "stack exchange" are nearly always going to have good information.


Sorry, you did mention "not overwhelming" - In short...

Buy this: http://www.ebay.com.au/itm/UNO-R3-Board ... SwMmBV1RWD

Download the Arduino IDE from arduino.cc

Work through the tutorials in the Arduino IDE.

If you get stuck, google search as follows: arduino + "prroblem you have"

Only then should start a project on the car. It really is quite simple, but there's a lot of little things you need to know before you can just build a circuit and throw it in the car. I strongly recommend working through the tutorials first before you start on the thing you want to build. Stuffing up and setting fire to your breadboard costs about $5. Stuffing up and setting fire to your car costs a lot more

Cus what would the end price be for your proposed kit?

Probably somewhere between $400 and $500 at a guess. As Droo points out, the wiring loom will get fairly out of control depending on how many features and functions people want.

[greenMachine]

Are these related to the PDMs from Racepak, Motec and others? Would need an ecu though, and a canbus probably ... ?

[Magpie]

Look at http://infinitybox.com

[Cus]

greenMachine: Not a PDM, or an ECU - think "all the other bits" - windows and locks and lights, things people tend to strip out for reasons of "because racecar"

Magpie: The infinityBox system does some cool things. And costs an absolute shitload. US$500 for just the module that controls motors (ie: power windows and central locking) and another $1000 for the "brain" and "10 power points" - and that particular module is only rated to 85degC (the power module is 125degC, the brain is also only 85degC) which means it'll be as reliable as my prototype when the car is left in the sun.... I do like the concept though, and it looks to be a full CanBUS system, which my inner nerd thinks is excellent.

Maybe I need to reassess my priorities and build a better version of that product, because there are 120deg+ rated chips for all of the functions I can see that doing. Sure, you pay a premium for these components, but based on their pricing structure the customer is already paying a premium, the least they can do is include the goods!

The temp rating won't make that much of a difference if you're building a garage queen, show car or something that never goes out in extreme heat or cold. Race cars get hot. Cars left in the sun get hot, commuter cars doing normal driving for long distances in summer get hot. I can't help but feel that system would leave the average Australian user feeling disappointed every summer, potentially walking.

In other news, I've just discovered Amtel make a 53-I/O 16Mhz chip with 32/64/128K memory which is rated to 125degC and ...wait for it ... HAS BUILT IN CANBUS SUPPORT!

*orders product sample*

Yeeeaaahh.... this may have just escalated wildly.

[Rolley]

Thanks for all of the info Cus. I've moved it to the top of my reading list at work.

As for rain sensing wipers, back when I was on the tools they weren't super common in anything under the $60k mark and they were pretty buggy. Early systems were percussion based and in some cases would activate the wipers when rocks or dirt were kicked up on the screen by other cars.
Later systems went optical, using sensors that reflected a beam back off the windscreen. If water was on the screen over the sensor patch the beam would not be reflected correctly and the wipers activated. The level of deflection of the beam changed the speed.
How they're doing it these days I have no idea. Maybe something similar to that uncle we all have who knows rains coming because his elbow locks up???

[Cus]

My knees do that (thank you, rollerblades!) I'll just wire something up to my knee and away we go!

Droo tells me it's optical based still, which means mounting a light + sensor somewhere at the base of the windscreen and aligning it correctly to actually work. I see a lot of room for error in an aftermarket installation here!

[droo]

yes..
Will stick with a kit that has the optics already made ready to stick on. Have reinvented several wheels in the past 2 years on mine..
I brained up the total time over the 5 months i rebuild version 2 of mine - 600 hours of dev and testing (about 200 dev, 400 on condition testing).
My lights run parallel with the existing car lights, so if my system were to fail, it wouldnt affect normal operation.
My indicators are an "unplug my kit" and "replug in the flasher can".
In 18 months, i havent had any issues with it's operation but i keep the flasher can spare just in case, and theres almost enough room in the centre console for it to lay spare.

And windows - no technical/electronic issues - just the usual when it's cold the passenger window takes ages to wind down, and thats not a fault of the embedded controller, thats the window motor!
Also this is unplug my kit and plug in the original connectors (no cutting of the indicators or windows).

Rolley - most of the electronics is the output of the controller driving a transistor driving a relay to control the everythings. The rest is all in software.