I began looking for a simple DB73 breakout board, with 90 degree mounted DB37/male/female on each end, something like this:
Perhaps with a set of tall headers and short jumpers down the middle to let you either break or just monitor signals on any/all pins. No LEDs, no ICs, just something simple that can be used with either the MS3 or MS3X connector, or both (with 2).
I have found generic breakouts that would be nearly impossible to connect to an installed MS because of the location of the connectors on the PCB, and very specific breakout boards like the jbperf.com breakout which only works for the MS mainboard not the 3X (and has a bunch of features I dont need), but nothing for sale similar to the above picture (which as far as I can tell is just a board layout drawing set allowing a member to have boards made up). Before I go the route of drawing up a board and having some made for myself (I only need 2) which can take a couple months and will probably end up with me owning several extra boards...Has anyone come across something like this for sale? Thanks.
This is a bit of a goofy idea but could work: get a straight wire-wrap DB-37 connector of one gender, and a solder-cup DB-37 connector of the other, and solder the wire-wrap pins on one into the solder cups of the other. Basically you'd be making a "gender changer" with long interconnect pins that doesn't actually change genders.
That would expose all the connections so you could probe them with a meter or clip onto them with test hooks or a scope probe.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking
Somewhere I have a pair of generic DB37 breakout boards with simple screw terminals, they were available with male or female connectors so I got one of each then I just used jumpers as required. Worked a treat, they were £10 each from a computer shop..
Eric's idea would work in a pinch to get quick access to the signals on either connector. Kind of tough to get to it when mounted inline with the mainboard connector and a 3X is installed, but not unworkable...Could always solder a couple stub jumper wires to a signal and ground, connect it up and hook the meter/scope to the stubs.
I think I will do this. Certainly better than where I am now. Thanks. - Walter
My recollection is that JBPerf offers the PCB for a BOB at a very reasonable price, I would just buy from Jean and not "re-invent the wheel". I think there is also a P/L on his site so you can easily buy the components from Digi-Key. What I especially like about his BOB is that it includes screw-terminals to easily attach leads or components to any pin, for proto work.
billr wrote:My recollection is that JBPerf offers the PCB for a BOB at a very reasonable price, I would just buy from Jean and not "re-invent the wheel". I think there is also a P/L on his site so you can easily buy the components from Digi-Key. What I especially like about his BOB is that it includes screw-terminals to easily attach leads or components to any pin, for proto work.
The problem with my board is that it is designed to fit the V3.0 or V3.57 pin out and you can't use it for the MS3X board which is what I think the OP wants.
racingmini_mtl wrote:
The problem with my board is that it is designed to fit the V3.0 or V3.57 pin out and you can't use it for the MS3X board which is what I think the OP wants.
Jean
You are correct, sir. If it did work with the 3x or I was only interested in breaking out the mainboard I would have purchased your board. The simple connector-connector suggested by Eric is one step simpler than I had hoped to find but I can make it work for me.
The pointer to eBay from mickeymarrows provided me with some options as well with a bit more functionality (wires could be unscrewed between boards to interrupt signals) than just the simple connector-conector, but quite a lot more complex (having to string 37 wires between boards) and 4-5 times the price.
I have to say if you were to design and market something just like what's pictured in the first post (a PC board with male and female DB37s and test points for each line) I'd buy one!
I'm a little surprised no such thing already exists in the market, but as far as I can tell it doesn't.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking
I think a way to break each connection is also very useful in addition to the test points. The problem I can see with the board in the first post is that it would not work for ignition when using standard coils and internal coil drivers; the traces would need to be much wider. That is also a problem if I want to use the same thing as my other board to break the circuits because the jumpers are only rated at 3A maximum.
It may be simpler to maintain a dedicated MS breakout board, and add the MS3X board - the outputs are simply too different.
As to amperage ratings, there are 8 channels on the MS3X that are rated to 5A. The injector channels could double-up the number of header pins, and use 4-way wired jumper sockets like a Harwin M20-1070200. All other channels are 3A or less, and would use the typical jumper cap.
Temporarily shut down - back soon!
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module TTR Ignition Systems
What could be done is to double up on all the pins that can carry high current for either the main board or the MS3X. That would mean the same board could be used for either connector which would likely be useful.
I agree, the ability to break connections is much more useful than just test-points. As is the screw-terms, for adding components, temporary sensor leads, test-points, etc.
That could add up fast. According to the MS3X chart, the various HT spark channels are 7A (3 pins needed), and the 2 main board injector channels are 14A (?!) each, needing 5 pins each. This last strikes me as odd since (IIRC) the DB37 pins are only good for 5A each.
Temporarily shut down - back soon!
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module TTR Ignition Systems
dontz125 wrote:That could add up fast. According to the MS3X chart, the various HT spark channels are 7A (3 pins needed), and the 2 main board injector channels are 14A (?!) each, needing 5 pins each. This last strikes me as odd since (IIRC) the DB37 pins are only good for 5A each.
I agree that it adds up fast. But the 7A can be covered by 2 pins since this is only a brief peak current (average should be much lower) and the injector channels use 2 DB37 pins each so by doubling up each pin that means each channel would have 4 pins (again the average should be ok).
So that would mean that the ratings is exceeded for some peak currents but on average that should be ok. And that excess would actually be less than it is for the DB37.
billr wrote:I agree, the ability to break connections is much more useful than just test-points. As is the screw-terms, for adding components, temporary sensor leads, test-points, etc.
Adding screw terminals would be nice but that has a huge impact on the board size and the cost. That could easily double both of them. So if I do this one, there won't be screw terminals. My original board can still be used for the MS DB37 if screw terminals are needed.
I agree that the etch shown in my photo above is on the small side for our use - at least for the outputs from the MS that source or sink an amp or more. Increasing the etch size would be easy especially if using a 2 sided board and the real limiting factors would be the density of the db37 connector at either end as adding a set of headers and jumpers in the middle of the board will necessarily spread the traces out.
I hadnt thought thru the implications of the higher current signals and limits of the typical jumper. From what I can find, a typical 2.54mm spaced header and shunt has a 3A rating (seems most of the DB37 manufacturers rate the contacts at 5A). Since these are not something one would want to have in place all the time and most of the higher peak current outputs have fairly low duty cycles, the worst case might be doubling up on the jumpers. There doesnt seem to have been any clever strategy to map mainboard and 3X board high current outputs to the same pin numbers on each connector so it doesnt look like just doubling jumpers on a few key pins would be practical as much as it would be confusing for a common breakout board, so it would probably be all or nothing. For me personally, I would be happy with just a single jumper per line, as I am not pushing any of the outputs of my MS3, having both the same is a plus for me, and these would only be inserted for troubleshooting.
Obviously, one option is to develop a breakout specific to the 3X. For me there is no advantage to having 2 unique breakouts. I have plenty of test equipment including a pair of JimStim boards, so I dont need anything but inline access to the signals on each while the MS is installed in my vehicle.
I have a couple of similar boards, with just a DB37 connected to a term strip on each. They are a bit cumbersome at times, but are very "universal" in letting me do any connection I desire to try. That's why I am a proponent of term strips and being able to break connections.
