JT's Enhanced Check Panel Thread

[5mall5nail5]

Extremely interested in this! Awesome updates. I'm way expired on my ee stuff but I still hand solder and rework SMT and Tig weld also!

Keep it up!

[Panici]

It's ALIVE!

My thoughts exactly.

[JehTehsus]

So while I did have some time earlier this week, I got about 5 parts onto the board before I realised I had forgotten to order some easy-to-get (i.e. not likely to vanish off the market) but still rather essential parts... like the main DCDC and LDO (oops). Anyway I built up what I had earlier this week, and the other critical goodies arrived this afternoon.

All the primary power rails look OK at first pass (have not connected the display yet), and the MCU comes up and talks to the JTAG probe just fine. Idle draw with nothing happening is around 40mA - this is likely almost entirely the MCU and the Ublox (hopefully, because it is way too fucking high for sleep mode!) At some point in the near future I will be soldering the final few passives onto the board as I bring up and test their associated circuits, but overall happy with how things are looking.

Note that there are some design changes with the R1 board, the USB circuit for example is totally different because of the processor change, and the only thing I have sanity checked on this unit is the connector footprint. But the switches/dials, LEDs, display, and most of the power front end I plan to keep the same, with whatever tweaks are needed based on testing out this first prototype design.





mmm.... dirty flux residue I have not cleaned off yet



It's ALIVE!

Firmware testing wise, I think the first thing I will tackle is the LEDs. The next big one is the switchable inputs, and the biggest and best (saved for last) is the display.

[JehTehsus]

I definitely do not have steady hands, but decent technique can overcome that issue for the most part. Same for TIG, although both get exponentially harder for me as I get to more uncomfortable positions where I can’t prop my hand.

I would make an absolutely terrible surgeon - usually I don't start on any board assembly until at least the second cup of coffee, and it is downhill from there.

That said, proper bracing, board holders and a reasonable selection of tweezers and I can comfortably solder 0603, and even 0402 and smaller if I take my time. 0.5QFPs/QFNs are actually not bad - if placing manually I stick em down with plenty of flux then brace angled tweezers against the board at opposite corners and twist to do very fine alignment - only takes a few seconds. My hands are not steady enough to just place the part correctly.

Going beyond that though I would need a rework station - I won't be manually aligning a 0.5mm BGA with any real hope of success in a reasonable timeframe, for example (pitch is the same, but so, so much more sensitive to placement errors due to the grid, and way harder to tell when you have screwed it up).

In project related news, I plan to assemble the R0 board tomorrow evening, ideally at least get JTAG talking.

[mikey.antonakakis]

You guys must have way steadier hands then I do!
Sometimes I struggle with regular through-hole components.

I definitely do not have steady hands, but decent technique can overcome that issue for the most part. Same for TIG, although both get exponentially harder for me as I get to more uncomfortable positions where I can’t prop my hand.

[Panici]

You guys must have way steadier hands then I do!
Sometimes I struggle with regular through-hole components.

[JehTehsus]

Wow, consider me impressed! I've got a couple generations of Metcal MX-5000s at work, love using such nice equipment. The newer one has "connection validation" which is a bit gimmicky but the on-demand power is so smooth. 0.5mm 48-pin QFP was not so hard to get really nice with a good hoof tip. Recently got a Hakko FX-888D at home, best I had was a moderately sharp cone tip, much tougher to get a 10-pin 0.5mm IC on the board, so I totally feel you on good equipment. My dash display PCBs came without that 0.5mm 10-pin IC so I've gotta do those by hand, going to take it to work to use the Metcal for it.

I have to agree regarding the metcal unit - extremely happy with mine, but CV stays off as I just find it annoying. I guess if I ever have an intern working out of the house it might come in useful for a bit, but that is rather unlikely:



I usually solder 0.5 QFPs, sometimes under the magnifier, with a fine tip (either a conical ~0.4 or a chisel tip held sideways). Hoof may be easier but I don't have one and have not tried it. The trick I find is to just use a very tiny amount of solder - so you need a very fine solder gauge. Do that, with plenty of flux, and it goes very fast. It is unusual for me to even bridge a pin on a 144-LQFP anymore.
For inspection, I would very highly recommend a cheap USB microscope. It makes spotting bad joins so trivial the $40 or whatever they cost is well worth it.



Aden, if all you want is a little touch dash or something, then I totally agree a phone would be the way to go. In this case the physical buttons and non-capacitive touch screen are intended to be fully compatible with gloves, and it is hard to screw up (hit the wrong one, hit it twice, etc.) relatively large locking switches and dials when 99% of your attention is focused on the next corner or the guy riding your ass.

[ADEN]

Good idea to replace the basic stock check panel.

An affordable easy option in my guess (for standalone ECU owners) ..Stock check lights might be tricky to add but possible:

An Android phone equal in size of the check panel with 3d printed frame (to look neat) would be more easy to connect using both USB to serial or Bluetooth to your MS,Speeduino or any standalone via apps like MS Droid, MS Tune, Real Dash...etc.

Just an idea...

[mikey.antonakakis]

Wow, consider me impressed! I've got a couple generations of Metcal MX-5000s at work, love using such nice equipment. The newer one has "connection validation" which is a bit gimmicky but the on-demand power is so smooth. 0.5mm 48-pin QFP was not so hard to get really nice with a good hoof tip. Recently got a Hakko FX-888D at home, best I had was a moderately sharp cone tip, much tougher to get a 10-pin 0.5mm IC on the board, so I totally feel you on good equipment. My dash display PCBs came without that 0.5mm 10-pin IC so I've gotta do those by hand, going to take it to work to use the Metcal for it.

[JehTehsus]

Assembling all that by hand? Yeesh!

Heh, this is nothing! And I am primarily firmware guy, believe it or not. My bench is comfortably setup for easily working down to 0603 and 0.5mm QFPs, which is my usual prototyping size. I start to slow down at 0402 and anything smaller than that is entirely done under the microscope and really slow. Depending on the board and component count I may or may not use a stencil, paste and the air gun. These R0 prototypes for example are getting close to the limit part count wise I want to manually solder down, but doing placement only for hot air re-flow I can go a lot higher, just time/effort tradeoffs that have to be decided on when ordering a board. In my experience prototyping it is fastest to just hand build (or manual placement+hot air reflow) basically anything in volumes of 1-5 units, you spend more time dicking around with the manufacturer and spend way more money just to find out one of your footprints is critically wrong, which takes two days to track down on a fully assembled board and a few minutes to discover when you place critical IC's one by one and check stuff with the bench meter. I think assembly quality and speed is actually almost all down to having good tools. And for some stuff like finer pitch BGAs they are probably not feasible to prototype at all without good tools like a proper rework station, as density and size goes up hand placement becomes borderline impossible to do correctly, and even when done perfectly properly re-flowing a decent size BGA is a bit tricky without automated temperature control and a pre-heater.

[mikey.antonakakis]

Assembling all that by hand? Yeesh!

[JehTehsus]

Bare prototype boards arrived today. I don't have time to start the assembly yet, but I hope to tackle it before the long weekend (or at least get most of it out of the way so I can get to basic electrical validation next week). All the new footprints check out OK, at least mechanically. These are super quick and dirty but I am reasonably happy with how they turned out, especially given the time involved:

[JehTehsus]

Oh hey, not sure how much you've messed with pulling data from MegaSquirt, but I've got a library for that if it's helpful:

https://github.com/mantonakakis1/MegaCAN

I'm eventually planning to fully implement ALL of the Megasquirt CAN protocol into it, but works great for dash display and expanded Megasquirt inputs as-is.

Very cool, thank you for sharing.

I am not building this on an Arduino, but I will be writing the firmware in C++ so it could likely be usable for me without too much hassle.

Still waiting for the prototype PCBs to arrive so I can start validating the peripheral set and mechanicals. In the meantime I am working on finalizing the R1 setup and am almost at the point where I cannot proceed until I am done with the r0 prototype, so that is good.

[mikey.antonakakis]

Oh hey, not sure how much you've messed with pulling data from MegaSquirt, but I've got a library for that if it's helpful:

https://github.com/mantonakakis1/MegaCAN

I'm eventually planning to fully implement ALL of the Megasquirt CAN protocol into it, but works great for dash display and expanded Megasquirt inputs as-is.

[JehTehsus]

While I do think it would be super cool to integrate a camera as well, I just don't think it is feasible in this project - chip availability is so bad right now I am already having to make a bunch of 'weird' compromises I would rather not have to spend time and effort on just to make things work as is.