iDrive 6 + Keyless entry + BMW Connected Drive

[Bry5on]

It’s hard to put into words how much effort and willpower I’ve been putting into this. My boards were not designed appropriately. I found someone local to make iterative adjustments. I’ve been back to him twice. It’s just been so much of: try, determine what’s not working, schedule a repair time, drive out, drive back, test, determine what’s not working, repeat. You hit a wall where you realize it’s just not happening.

So I’m back to the drawing board, back looking for a designer, back to dealing with getting components. I’m really sad about it 😅

How messed up are the boards? I’ve done a few white wire fixes in my day and have a soldering setup here at home..

You have the schematics and the gerbers?

[YoitsTmac]

How messed up are the boards? I’ve done a few white wire fixes in my day and have a soldering setup here at home..

You have the schematics and the gerbers?

I have everything. The intent was to write firmware for these boards and then make mild changes. I’d have to tap into a tiny resistor to deliver 3.3V to the circuit. My designer forgot to connect it.

But after so many mild changes, I’d rather run a new batch with some updated changes: new cellular board and new gps module for better reception

[Bry5on]

I have everything. The intent was to write firmware for these boards and then make mild changes. I’d have to tap into a tiny resistor to deliver 3.3V to the circuit. My designer forgot to connect it.

But after so many mild changes, I’d rather run a new batch with some updated changes: new cellular board and new gps module for better reception

I mean we can at least get you to functional boards so you can start hardware in the loop testing of the software - then you're not stuck with a longer critical path. Just say the word!

[George Hill]

Definitely Bry5on, if you are just trying to prove the concept modify the board you have now. You might also find something else that needs to be changed for the future redesign.

I've got a couple DMEs repaired with a similar concept. Works just fine for your situation and easy peasy. IIRC this is solid core wire from a CAT5 bundle




And when we designed a PCB wrong, jumper to the rescue.

[YoitsTmac]

All right, everyone, I had a little bit of a freak out on Tuesday, or whenever I was having issues. I made what feels like a bazillion calls, and everything kind of magically fell into place. There are kind of two things at play: The first thing is I have these existing boards, which will now need their third iterative adjustment to them just to get them to work. The next thing is that, based on the firmware I've already tested, some things are really poor, including the GPS accuracy it's really good at saying you're at some place at the end of the cul-de-sac, but not really being able to have the accuracy strong enough to even say which building you'd be in or the left or the right side of a cul-de-sac.

So I did what any person would do in this situation, which is do a complete design overhaul. I've actually completely changed nearly everything on the board. I'm working with a local designer to implement a new cellular modem, a new GPS module, and even a new way to communicate with CAN bus. So there's very little that's left of the original design. I'm meeting with the new designer later today, or at least that's what he says. He said the same thing yesterday, but I understand we all have lives.

My biggest issue with my last design was how long it took to go from completed design to in my hands. While the PCB itself was made within a couple of days after submission, the assembly took 30 to 40 days, and then shipping took another 10 days. There's very few things that are more depressing than the thought of having to wait essentially two months for another prototype. So, thankfully, I found someone local who can do the assembly. Once the design is finalized, I have a good contact with the supplier, and I will begin the order there at the same time that I begin the manufacturing process of the PCB. And at the end of it, the PCB and the components required for the PCB should be arriving within a few days of each other. This should give me a new prototype within the next 30 days. Hopefully less. ..... But realistically, not.

[heinzboehmer]

And when we designed a PCB wrong, jumper to the rescue.

Even big companies do it! https://youtu.be/onxJqNzUyk0

My biggest issue with my last design was how long it took to go from completed design to in my hands. While the PCB itself was made within a couple of days after submission, the assembly took 30 to 40 days, and then shipping took another 10 days. There's very few things that are more depressing than the thought of having to wait essentially two months for another prototype.

Maybe I'm misreading, but are you subcontracting the board manufacturing and assembly to your designers? I've had pretty good experiences with the typical big fab houses (JLCPCB, Osh Park, etc.), both overseas and domestic. Time from clicking "buy" to having the boards in hand is usually 1-2 weeks.

If you want super duper fast prototyping, you can get some blank boards and find someone (or a maker space) with a desktop CNC to mill them out for you. You can buy special rivets to use in place of vias. Then assemble by hand and throw them on a hot plate. This method assumes you're designing two layer boards, of course.

[YoitsTmac]

Even big companies do it! https://youtu.be/onxJqNzUyk0



Maybe I'm misreading, but are you subcontracting the board manufacturing and assembly to your designers? I've had pretty good experiences with the typical big fab houses (JLCPCB, Osh Park, etc.), both overseas and domestic. Time from clicking "buy" to having the boards in hand is usually 1-2 weeks.

If you want super duper fast prototyping, you can get some blank boards and find someone (or a maker space) with a desktop CNC to mill them out for you. You can buy special rivets to use in place of vias. Then assemble by hand and throw them on a hot plate. This method assumes you're designing two layer boards, of course.

I already have a couple wires running around my board. It’s just so far off the spec that at some point you just have to admit it’s time to go back to the drawing board.

For this first board, I subcontracted the design designing to one person, and I handled the manufacturing subcontracting myself. For this next iteration, I handed a rough draft of my new design to my designer, we’re currently talking tonight getting the spec fully concrete.

From there, the current plan is to have the PCB done overseas and I have a component supplier in North America that I plan on using. So I can have the parts order being put together and in transit at the same time that the PCB is being assembled and in transit.

Then the idea is to have both the PCBs and the components arrive at roughly the same time, where my designer would then handle the assembly. He did an incredible job repairing my current boards, and I fully trust him with this step.

When I had the first design assembled overseas, I saw my board had been completed in a really timely manner, but the assembly took a very long time. Granted, my very first board design carried a component that was basically impossible to source. Which I definitely outlined here in this thread. So that exacerbated the issue, but even after the BOM was finalized, it took 3 to 4 weeks to complete assembly.

The board is actually somewhat complex. I don’t believe I have shared the entire spec yet because I have some extra bells and whistles that I want to be a surprise and first reveal at a software level. The last design had about 130 components.