My how much you've grown, senior Pegasus!
I always love unwrapping a new PCB!
I always love unwrapping a new PCB!
Controlling the Instrument Cluster's Display
A little project I'm working on.
(Sorry for the horrid picture!)Here's the elevator pitch: Directly control the LCD panel with a microcontroller to display custom information on the instrument cluster. The microcontroller will also read the data that would normally be going to the LCD and can choose to display that info or custom info.
Maybe you want to display OBDII parameters where the MPG is. Maybe you want to change the charge, assist, and SOC gauges to accurately reflect amps in/out, real battery SOC, etc.
I've got a few other ideas as well. Once I'm finished with this project I'll open-source everything I've learned and perhaps produce some PCBs to sell. We'll see!
I have work and other projects as well, so it may be slow going at times. But I'll try to give updates fairly regularly.
I don't think this has ever been done before. I hope you guys are excited!
If anybody is or wants to work on something similar, I'll be glad to share what I know; just ask.
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Sweet, glad you've already figured out your particular bootloader solution.
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I have a confession: I've (still) never used a USB-C cable for data transmission... not even once, for anything, ever. I suspect many G1 Insight owners are in the same camp. If my assumption is correct, then I recommend using aUSB-A USB-B connector for Pegasus firmware update process.
USB-C is certainly the future standard, but IMOUSB-A USB-Bis more appropriate for this application. It's not the end of the world either way; USB-C-to-A adapters cables are cheap and transparent above the PHY layer.
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LiBCM will never support METSCI updates... that would be so much work. But maybe I'll consider adding BATTSCI updates to LiMCM, so that you only need to connect one USB cable to update the entire IMA system.
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I have a confession: I've (still) never used a USB-C cable for data transmission... not even once, for anything, ever. I suspect many G1 Insight owners are in the same camp. If my assumption is correct, then I recommend using a
USB-C is certainly the future standard, but IMO
...
LiBCM will never support METSCI updates... that would be so much work
. But maybe I'll consider adding BATTSCI updates to LiMCM, so that you only need to connect one USB cable to update the entire IMA system.
General comments/questions:
1: Where are your reference designators?
2: What is the purpose for the MS621T lithium battery? realtime clock? Could it be a supercap instead? I see that it's rated up to 85 degC, but if nothing else a supercap doesn't need to be replaced down the road.
3: Your buck SMPS (bottom left corner) is laid out 'long'. Ideally you'd place the input caps much closer to the inductor. In a buck configuration, the input capacitor proximity is much more important (than output capacitors) because the current through the input side is discontinuous, whereas the output current is regulated by the inductor. Here's a better layout (from LiBCM):
![Colorfulness Pink Font Magenta Red]()
(U1 is switcher, top copper fill is Vin, middle is ground, bottom ('+5V') is Vout).
4: Same SMPS: Is the diode to the left of the inductor used for over-voltage, or is this a non-synchronous buck? At 5 volts output, I recommend using a fully synchronous converter, as it will greatly improve efficiency. For a fixed +5V output, my goto is AP63205. Given your inductor size, AP63205 might not source enough current.
5: What is just above the "REV A" silkscreen? Is that a switched open drain?
6: Is the oscillator (to the left of the I2C board connector) stable that far away from the STM32? Maybe it's a low frequency RTC? If it's the system clock, stray capacitance might make it unstable.
7: Those 0.1" headers to the left of the CPU are honkers. If you're looking for a slightly smaller header, I recommend the 2mm C2C Hirose DF11 connector (e.g. DF11-8DS-2C). The terminals are still easy enough to crimp, plus you can purchase pre-crimped leads directly from the manufacturer.
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If you do end up getting a pick and place machine, you're going to need machine vision for parts that small. For reference, our Neoden 4 machine can only accurately place parts down to 0402... and that's with machine vision and slow speeds. My personal Neoden 3 - that I use to assemble LiBCM PCBs - doesn't have machine vision, so I end up having to manually reposition parts smaller than 0805.
Given how expensive these machines are, if you're only planning to build Pegasus PCBs, then probably contract manufacturing makes more sense.
1: Where are your reference designators?
2: What is the purpose for the MS621T lithium battery? realtime clock? Could it be a supercap instead? I see that it's rated up to 85 degC, but if nothing else a supercap doesn't need to be replaced down the road.
3: Your buck SMPS (bottom left corner) is laid out 'long'. Ideally you'd place the input caps much closer to the inductor. In a buck configuration, the input capacitor proximity is much more important (than output capacitors) because the current through the input side is discontinuous, whereas the output current is regulated by the inductor. Here's a better layout (from LiBCM):
(U1 is switcher, top copper fill is Vin, middle is ground, bottom ('+5V') is Vout).
4: Same SMPS: Is the diode to the left of the inductor used for over-voltage, or is this a non-synchronous buck? At 5 volts output, I recommend using a fully synchronous converter, as it will greatly improve efficiency. For a fixed +5V output, my goto is AP63205. Given your inductor size, AP63205 might not source enough current.
5: What is just above the "REV A" silkscreen? Is that a switched open drain?
6: Is the oscillator (to the left of the I2C board connector) stable that far away from the STM32? Maybe it's a low frequency RTC? If it's the system clock, stray capacitance might make it unstable.
7: Those 0.1" headers to the left of the CPU are honkers. If you're looking for a slightly smaller header, I recommend the 2mm C2C Hirose DF11 connector (e.g. DF11-8DS-2C). The terminals are still easy enough to crimp, plus you can purchase pre-crimped leads directly from the manufacturer.
...
If you do end up getting a pick and place machine, you're going to need machine vision for parts that small. For reference, our Neoden 4 machine can only accurately place parts down to 0402... and that's with machine vision and slow speeds. My personal Neoden 3 - that I use to assemble LiBCM PCBs - doesn't have machine vision, so I end up having to manually reposition parts smaller than 0805.
Given how expensive these machines are, if you're only planning to build Pegasus PCBs, then probably contract manufacturing makes more sense.
That layout is absolutely better in every way. Ha, that's so many ground vias.Ah, yeah, you are right about the scope bandwidth. I don't have a better scope to look with unfortunately.
That USB story is wild, hah. I guess you do what you have to do to get things working. Classic example of using software to fix a hardware problem.
Here's the best layout I could come up with, what do you think?
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That's a great scope! My daily driver at NI was a 2 GHz ABW Tek DPO. Whenever we needed more bandwidth we'd typically just rent test equipment.I do now.
Tektronix DPO7104, 1GHz bandwidth and 20GS/s. Used eBay scopes are awesome, this was about 1/5 the price of an equivalent modern scope. It won't perform as well as a new scope of the same caliber, but it still has excellent specifications and features.
Each active probe I used at NI cost more than the entire scope setup I use now. Honestly the real-world analog performance is almost entirely a function of your input probes.
Are you using the base firmware you previously wrote for the old hardware?
IIRC, previously Pegasus was powered from the +12V rail on the OBDII port? Why the change? Does the new power harness require soldering?
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