Jaguar Ideas for the Future
Posted: Wed Sep 26, 2012 3:13 pm
Please post any ideas to be included on future Jaguar boards in this thread.
Thank you,
Thank you,
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Fred, it is a bit hard for this old brain to understand the specifics of your observations. So you applied 12V to one of the analog input pins, measured 5.6V at the input to the cpu and measured 5.3V on the "5vc -analog" net / rail?Fred wrote:Dual reg + 5V6 zener + 470 ohm inputs + schottky diodes = bad conditions for the CPU. 5V1 might be a better choice IF it doesn't conduct too much at idle. If that doesn't solve it, we need to rethink the protection as it's currently not 100% safe. I measured 5.6 at the pin with 12v applied to outside. BUT, I measured 5.3 on the rail. This screws all of the ADC readings pretty badly and puts the pin at 0.6V over the digital supply which it's attached to.
Fred.
Lies! And I have proof:TonyS wrote:Fred, it is a bit hard for this old brain to understand the specifics of your observations.
Yes. See :-pSo you applied 12V to one of the analog input pins, measured 5.6V at the input to the cpu and measured 5.3V on the "5vc -analog" net / rail?
Start it! This is a cross discipline issue, though. It's part power supply, part pin protect.I have a bit more to say but perhaps this should be the start of a new thread in Hardware as I see that the topic of power supply design is a ToDo item for Ravage.
AgreedWe will be moving to a compulsory GP naming scheme. I don't know the details, but calling an output FAN when it can be used for anything low side up to X amps is not going to be allowed. ACC might not be the best idea either, although it's on the right track. Maybe LS1 and LS2 for Low Side, or something like that. Have a think.
Wouldn't this be a noisy environment when the injectors are firing? Not sure if this would be a good idea for a prototyping area.Fred wrote:(10:49:26) Fred: just noticed BIG space on under side of dpaks perfect for more perf board circuits
I do need to re-visit the size of all the solder pads, so there should be some space saving changes as these are re-sized.Fred wrote:(10:55:58) Fred: DeuceEFI: the diode pads for the led blockers are way too big for the std parts, some space to save there?
I do like this idea as I found myself referring back to the schematic to figure out which one to change while we were testing the signals.Fred wrote:(15:02:19) Fred: DeuceEFI: which jumper controls inversion for the DIS bypass in/out
(15:03:12) Fred: JP2
Perhaps label on board? Rather than JP2 and JP1 have DISP and IGNP ? or whatever.
I will give this some additional consideration.Fred wrote:Could put vias on all of the dpak pads and cut around the vias on the other side. Not really necessary though. They won't get hot unless shorted.
The SMD XOR is smaller that the DIP XOR chip, but we are using a chip with the largest number of gates (4 gates) that I can find. Note that two of the unused gates on the chip have their inputs tied to +5v.Fred wrote:Did the SMD XOR make room for a bigger XOR with 6 gates?
Yes, this was a concern of mine as well.Fred wrote:More clearance around pads that aren't ground pads. easy to short as is, should the green be scratched, hard to see such shorts. Hard to ID if grounded or not, too.
I have already moved the components for the MAP input around so that the diodes, capacitors and the resistor are not under the on-board sensor.Fred wrote:MAP input protection is easily doable as is, though you could do:
(19:13:26) Fred: what about for ext users: change 1k to 470, have one more 470 outside, put the diodes before the caps and internal resistor, add another pin cap like the other external signals have
(19:13:31) Fred: so rather than routing it around the back
(19:13:41) Fred: you put a cap and further resistor with the diodes in front
(19:13:55) Fred: and just get the installer/builder to use 470ohm in the stock location
(19:14:28) Fred: then you get correct filtering, and might ease the layout, and keeps the R before the diodes low (to counter leakage)
I'm not a fan of the current diode wrap around setup. When I suggested it, I hadn't looked at the schematic and layout to see what it would mean.
We need to discuss this further as to what to name them and I do agree these outputs need to be renamed.Fred wrote:We will be moving to a compulsory GP naming scheme. I don't know the details, but calling an output FAN when it can be used for anything low side up to X amps is not going to be allowed. ACC might not be the best idea either, although it's on the right track. Maybe LS1 and LS2 for Low Side, or something like that. Have a think.
I do have a 5V1 zener in my parts bin and I will test it in place of the 5V6 on my Jaguar A2 board some time in the next few days.Fred wrote:Dual reg + 5V6 zener + 470 ohm inputs + schottky diodes = bad conditions for the CPU. 5V1 might be a better choice IF it doesn't conduct too much at idle. If that doesn't solve it, we need to rethink the protection as it's currently not 100% safe. I measured 5.6 at the pin with 12v applied to outside. BUT, I measured 5.3 on the rail. This screws all of the ADC readings pretty badly and puts the pin at 0.6V over the digital supply which it's attached to.
With Jaguar being a DIS/EDIS focused design, I'm going to stay focused and not try to make this a general purpose board.DaWaN wrote:High side driver for Honda VTEC
See my response above ^ and Fred's response below:DaWaN wrote:8x 5V logic outputs for COPs/coilpacks with driver inside
Fred wrote:DIS and EDIS do the coil control for you, hence no ign drivers. 5V logic isn't good enough for most ignitors anyway.
I will "try" to find space for this, but we might want to discuss this being an add-on board.DaWaN wrote:Stepper motor driver for GM idle valve