Development of DIY Electronic Upgrades

Hey all, I don't post much in this forum, so I apologize if this is off topic or doesn't belong here. My main goal of this thread is to assess if there is any interest out there for me to put the effort into developing some DIY electronic stuff for third gen Tacomas.

I bought a 2019 Tacoma during Thanksgiving of 2018. The process was rushed, because my Xterra broke down spectacularly, and I did not have the luxury of doing tons of research into buying a new vehicle based on work and location. Therefore, some of the bells and whistles that I wanted to have in a new vehicle were not options. If those bells and whistles were on my vehicle, I may not have been inclined to start this thread.

As some background, I am a professional computer & electronics engineer that works on embedded systems as my day job. I have researched aftermarket options for stuff that I have wanted, but there is always something missing or some deficiency. I would rather look at making something that exactly fits what I want to do. Furthermore, when you choose an aftermarket upgrade (such as a new head unit) its not really an open system that you can tinker all that much with on the low level. I want whatever I make to be "tinkerable" so anybody can modify it or upload new firmware to get new features.

Remote Start
So.. the first thing that I want is a remote start that doesn't have the drawbacks of what's out there for push to starts on Tacomas. I have researched this and the biggest gripe I have seen is that for remote starts, you have to start your truck twice, because once you open the door, the vehicle turns off as a Toyota safety feature.

After talking to a few buddies who are more versed in this than I am, I can understand possible reasons that Toyota did this. The biggest reason I can see is because Toyota cannot guarantee that "their" own system started the vehicle. Let's say for example the vehicle gets started via cell phone. Well, who started it? What if a thief managed to get hold of the cell phone # used to start the car? In this case, the security issue is mitigated by stopping the vehicle when the door opens.

The previous is one very brief possible explanation. However, instead of Toyota trying to mitigate all the potential security issues with aftermarket remote starts, they put in a catch all with the door thing as its easiest. I can understand their reasoning, but I think there are other ways to solve the problem and keep the security aspect.

Some people have suggested to just tinker with the door sensor so the vehicle won't know you opened the door. The issue with this is that from an electronic standpoint, the ECU or BCM can implement a "state machine" in the firmware, where only a valid state leads to the full "takeover" procedure that is ideal. By tinkering with the door sensor, you will not only lose the built in features of that sensor like automatic lights when the door opens or whatever, but the ECU would not be in the proper state for a takeover procedure.

As it stands now, (I am going to speculate), in order for a proper takeover procedure to occur, several things have to occur. We can identify these things just by looking at what you would normally do when you start your vehicle. Let's start from a static state of the vehicle being 'locked'.

1. User unlocks the door via key fob OR door handle sensor OR whatever. ECU detects this electronically and goes into vehicle unlocked state
2. User opens the door. ECU detects this via door sensor and goes into idle state
3. User depresses the brake pedal. ECU detects this via brake switch and goes into ready state
4. User depresses PTS switch. ECU detects this via switch and starts the vehicle.
5. ECU goes into car running state

There could be other permutations, but this is one sequence we absolutely know works, because you do this every time you start your vehicle. Keep in mind that at each one of these steps, the ECU can firstly determine if there is a key fob in range and reject any input if it is not. Now, if it was as simple as the above sequence to get a remote start to work without the second start, we would see a lot of them on the market already. The issue is the pesky immobilizer system.

So, as I understand, the immobilizer system (imm) is a separate module from the ECU that deals with detecting the key fob via RF and decoding its built in digital key numbers. My theory is that this module can act as a "master" or "slave" to the ECU.

1. In master mode, the imm detects the RF signal from the key fob and sends a request to the ECU. This would occur for actions such unlocking or locking the door from a distance with the fob
2. In slave mode, the ECU "asks" the imm unit if the registered key fob is in range. This would be for actions like pressing the unlock buttons on the door handle and the push button start.

So if the above is true, I would like to get my hands on an imm unit and an ECU to reverse engineer the actual communication happening between the imm and the ECU. If this communication can be intercepted and "spoofed", it would be possible to bypass the imm unit and spoof every action in the remote start sequence so the vehicle "thinks" a person went through all the steps above (1 - 4) to start the vehicle. This would allow a 'proper' remote start without the drawback of the second start due to the door opening.

Head Unit
I am not impressed with the head unit that came with my vehicle at all, considering I paid 37K for a new TRD Sport. The HVAC and head unit controls are akin to the controls in my '05 Xterra. I would have expected that almost 15 years later, the situation would be better.. but that's another discussion.

Why not go with an aftermarket one!

Herein lies my beef. Yes, I can go with an aftermarket one, but it 'always' missing something. I want to modernize the head unit and have something that has multiple USB C ports with power delivery support. What about being able to press a button to have an always view able backup camera? This feature should be built in.

I would like integrated HVAC controls that work with the remote start. I am thinking there would be 2 modes of operation - manual and auto. Manual mode is what is currently in the vehicle. Auto mode would allow you to manipulate the controls electronically through the remote control. For example, you forget to set your fan speed to 4 before you got out this morning. Through the remote control, you could just set it to 4. Lastly, auto mode could work in temperature mode where the module modulates the fan speed and heat settings to regulate a set temperature within the cabin.

GPS integration is a little more involved. I am still looking at options here as there nothing I can find online (Garmin / Waze, etc..) is "open" and allows easy and fast integration into the truck sound system.

One feature I want for the GPS system is direct integration into the sound system for turn by turn navigation. The issue is that you will undoubtedly have several audio "channels" running in parallel. I would like all background audio channels to mute or lower their volume some seconds before and after the GPS is giving a direction. Kinda like listening to a pilot in flight.

PS, yes I am aware of the all time camera view mods found on this forum and elsewhere. What I am saying is that if I am building my own head unit, I want it to be integrated electronically into that as another app or window.

Security
With regards to what has been discussed, security is a topic for another time for something like the immobilizer. All the security checks would still be in place with a custom system.

One thing that I was thinking about is the possibility to make little standalone security modules that have integrated LTE / GPS / Bluetooth support that you place around the vehicle. I am not sure if something like this already exists.

The premise is that you would have a minimum of 2 of these security modules placed around the truck. They are all connected via local network and have 2 power sources: vehicle battery AND built in battery. These modules are always talking to each other and monitoring their power status. If one of the modules goes dead, another module will immediately detect this and send out a cell message via LTE that something is wrong. Subsequently via the built in GPS, you can send sms messages to the modules to ping them and their location.

In order for the vehicle to be stolen without notice, a thief or team would have to disable all of the modules inside the vehicle at the same exact time (within some milliseconds). That is extremely hard.

Conclusion
So after all this and my thoughts, I am just spit-balling here. My real question is if I am just wasting my time or if there is actually interest in stuff like this.

Thanks

 

For someone that is just spit-balling, you don't seem to have a deep technical understanding of these things.

How do you expect to scope out the requirements and pay other people to make your ideas in a quantity, that IF people buy them, will not all come out of your pocket?

I've seen this dream before and it's basic business to make it worthwhile.

 

You mis understand. I am not paying anybody. I AM the developer. I can make these things myself. I was just wondering if there was a desire for me to publish this stuff. I guess I didn't properly explain that in the post, and you ended up making an assumption. Sorry.

I also have a technical understanding of the work involved. Believe me, I wouldn't have posted this if I was not willing to put in the time.

 

Don't waste your time thinking you should design a brand new head unit. Just take an off the shelf Android-based double-din unit and pay an engineer with embedded systems experience to build a USB interface to the existing wires on the HVAC and control it from there.

Apple CarPlay or Android Auto already does this.

 

Sorry, I misread the first post then. Some of the details did not make it apparent that you had this knowledge, for example the security one. That one is easily defeated with an (illegal) cell phone jammer that can be made under $50 - maybe less now then last time I read up on them.

 

Ok.. two guys under the wrong impression already. Did you read my post? I am a professional embedded systems developer as my day job. I know what I am doing.

 

OP you seem like a smart cookie. I look forward to anything you come up with, purely from an ingenuity standpoint. I find it impressive.

 

Go for it then! As a hobby, you should totally do it and post up some threads. As a business, I am skeptical that it would be that viable unless you also know the supply chain, logistics, and can hope that a new trade war and tariffs won't screw you over.

And yes, my eyes glazed over after the first paragraph... Making some tl;dr's and being more concise would have helped me not miss this.

 

Dude, it's right there in the beginning.......

If you're going to provide constructive criticism, at least read the thread you're posting in.

 

Jason Lee:

I will have to do my due diligence here for the security aspect; however, I do not think it is as easily achieved to spoof the communication. For example, let's take cell phone SMS messages as the communication mechanism from the remote to the module. The actual data that is being sent doesn't need to be static. In fact, it would probably be dynamic. I am aware of some attacks like rolljam, but I think there are mitigations depending on the encryption and encoding of the payload.

Additionally, this is not a business venture at all. Its just a tinkering project to make stuff happen. I have no intention of selling these, otherwise I fall into the same issue I dislike about off the shelf stuff. The idea it to make stuff available to others to be able to modify it.

Eat Sleep Taco:

Not sure if that is sarcasm or "I've seen this before" kind of talk; however, benefit of the doubt - Thanks

 

Nope, I'm being serious. I can tell just from your ability to craft an intelligible thread you're a step ahead of some people on this forum. Seems like you have an idea of what you're talking about, just haven't done the deep dive yet to see specifics.

 

That is correct. As my own engineer, I try to dissect the problems and make sure I can see the outcomes before I jump headfirst into anything. I have been researching and formulating some of my ideas and theories for a bit now.

 

I did, 3 times. I still stick with my post that I recommend making it more concise.

Also as a "professional" as in have my degree in computer engineering, yet have only been PAID for writing software since the degree, I have a deep understanding of the work behind each of the three ideas.

If I were a thief, I wouldn't bother spoofing any communication. It's way cheaper and easier to just jam the cell network rather than try and spoof things.

I still say go for it! I've had many similar ideas for my 1st gen, but at the end of the day since I don't have a workshop with tools, I haven't bothered with the combo head unit/HVAC controls, relocating the screen to a better spot in my dash, etc.

 

Curious to see where this goes. Could be a pretty sweet project.

 

I have been in the consumer electronics industry for 7+ years now doing all types of embedded and PC work: hardware, software, and systems design. I am not an academic.

As for jamming the cell network, you mean installing a jammer on the vehicle so messages can't come in or out I assume. My proposed idea isn't meant to be bullproof, but rather something that is an "addition". I mean, no solution is going to work if you know the frequencies you need to jam and install a jammer. I can easily envision a system that can transmit using broad frequency hopping, but I don't think there would be anything out there to receive it like a cell tower. My understanding is that cell phones in the US only use a single small frequency band. I'll have to look that up. Either way, I think that band is public knowledge (easy to jam) as you say.

 

Definitely keep refining your ideas. These are popular trucks that sell in huge quantities and the aftermarket accessory potential is wide open. If you can come up with unique quality products, you can make a lot of money. Right now I’m super intrigued by this product:

https://www.ktjo4x4.com/product/3rd-gen-toyota-tacoma-pre-order-heads-up-display-hud-/21?cs=true

Good luck and pm me if you wanna try out some prototypes

 

Thanks. I am definitely not in this for the money aspect.. and If I did end up trying to monetize any of this, people would be paying for the hardware components and the time to put it together. My goal would be to make a modifiable / hack able system and not a closed system... which is what most things are now.

That HUD unit may seem interesting to some people, but in particular it does not appeal to me at this time. Also, that seems to be a display technology, so no reason it couldn't be added at a later time by switching out the chosen display.

EatSleepTacos:
My priority would be the remote start, then the head unit, then the security. To be honest, I don't particularly care that much about the security aspect - it was just an idea I thought of. The purpose of the build would be to make it so anything I come up with allows the stock to still operate in the same way with the same security and features.

Lastly, keep in mind, with an open system like I am suggesting, also comes the ability for custom firmware updates. Its possible to upgrade the system in the future for the addition of a security module

 

I would be interested in a remote start take over solution as many others on this forum.
From a business standpoint it would be substantial.

As far as the other ideas you mentioned I don't believe that they would be worth the investment in time and money.

 

I can understand that the graphic head unit may not appeal to people with the stuff currently available; however, the remote electronic HVAC controls and the modern USB C ports I think are appealing. I think people overestimate the time it would take to integrate a graphic display with these types of control abilities. Sure if you do everything from scratch, it will take time; however, that's not my prerogative. The head unit would utilize an off the shelf PC or embedded system in which apps can be written. All the OS infrastructure is already there. I have done both low level OS firmware and high level app development, and the latter is an order of magnitude faster.

The real issue for me is the GPS integration. Even if I just left GPS out of it, this means (as it currently stands) I use my Garmin GPS with a stand on the dash. This is what I firstly thought, but if I am doing this I want that GPS integrated into the sound system. This is where the audio channel mute comes in. I don't want the turn by turn navigation voice blocked out by music playing. Hooking the GPS into the sound system is easy peasy through a head unit (assuming my understanding is correct). Basically I could take the GPS apart and tap off the signals to the audio speaker within the GPS. That then just simply goes into a mixer that has the GPS audio channel and the regular car audio channel. Then you control that mixer electronically to mute whichever channel you don't want at the time.

I reached out to Garmin recently to explain how to add the channel muting feature easily to their existing GPS without any hardware changes. Those GPS' already have a debug serial output that Garmin uses internally. All they would have to do is implement another serial output that spits out audio command alerts and potentially turn by turn nav alerts. Its stupidly easy on their end, and they would be loved by all the system integrators and hackers out there. But... having experience in a large international company like I have, I fully understand them just throwing out my comments.

 

Assuming you have the tech skills to make these things happen, and like doing that sort of stuff as a hobby, go for it!

Since the aftermarket is so big for these trucks, I would expect a lot of hours have already gone into trying to solve the "shuts off when the door opens" issue with remote start. If you figure it out, you could easily turn that into a saleable product that others haven't figured out how to make.

As far as head units go, others have suggested, I would also suggest an android based unit, with the addition that you'd probably want to replace the firmware with something from https://www.xda-developers.com/ for maximum cusomization options. Take a search through the Audio/Video threads for reviews and info different head units, and loading firmware and/or apps. Pretty sure some of the head units I've seen there have dual video inputs, so front/rear camera display on the head unit should be doable. If you want to build your own, great, but why do that when you could modify an existing, off the shelf unit to do the same stuff?

Regarding the security system. If you've looked at the existing COTS products, and android apps that might be able to tie in to existing sensors and modules, and still find some features lacking, homebrew would seem to be your only other option. Personally, that's a lot more work than I would put in for whatever function you are missing. Again, if it's worth it for you, then it's worth it.

Overall, it seems like figuring out which of the electronics controls, sensors, and various ECUs you can tap into via CANBUS or other existing communication busses would have the biggest bang for the buck. Once you understand the existing options, you can figure out what else is needed to meet your specs. If you need more functionality, then look at how to add it. Then build an app that you can load on the head unit to control the features you want to control. Easy, peasy, lemon squeezy, right?