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Thread: teensy 4 pad traces

  1. #1
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    teensy 4 pad traces

    I had a couple of cases where one of the pads that does not go all the way through the board was ripped off the fiberglass mechanically and I had a heck of a time repairing them. Is there any way traces on a future teensy board could be designed like an arrowhead so that if the pad is ripped off the board on a prototype it rips off at the narrow point and leaves a somewhat more accessible area of the trace to scratch off some insulation and solder to in a crisis when you have every other connection already made?

    Maybe this sounds like an insane request, or I need to post a picture or something, but if you have ripped off a pad or two while experimenting with prototype positioning, perhaps you can imagine such a design that might make life a little easier when an accident happens without using a lot more real estate on the board. If it's at all practical, just for the pads that dont go all the way through the board, please consider it.

  2. #2
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    straight headers combining the pads with the holes are good for support, i usually solder 4 rows of headers to cover the pads and pins, 2 rows each side

  3. #3
    Senior Member PaulStoffregen's Avatar
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    Maybe a picture or drawing would help explain your idea?

  4. #4
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    Name:  trace.png
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Size:  30.9 KB I hope this conveys what I mean, on the left is the hypothetical future arrowhead trace out of the factory, which would function just as the normal traces do now. On the right is the hypothetical disasterous situation where the pad has ripped off the board, but luckily there is a spot where the insulation can be scraped off with an x-acto and in a pinch a wire can be soldered there next to the original trace position. It's like a seatbelt, see? No effect when everything is okay, but when you have 40 wires hooked up to a board and your one open serial port connection gets ripped off, its slightly easier than soldering to the tiny thin trace connecting to the pad on the 3.6

  5. #5
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    i honestly dont think its a good idea to solder wires directly to the pads if it means the device/teensy will not be solid, if your going to do that you should do so safely and make sure both objects don’t stretch in any way, this goes for all pads on any device, not just teensy, you can get breakout boards for exposing those pads to outside pins or get special headers to solidify the connections if you think movement could risk another pad accident

  6. #6
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    In my case, I was working with a protoype teensy board I was putting into my own guitar, and one of the boards attached via serial, a midi board, got caught when i was making an adjustment and ripped off a pad. It wasnt a normally moving part. I can't believe noone else has had a similar experience. I had another situation very similar to this where I was still experimenting with positioning components and ripped off a pad, it takes a lot of effort to solder to the little traces and in some cases there arent enough alternate open pads. It's not a bug, but if a design similar to this doesnt take away from anything it might save someone an hour or two.

  7. #7
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    indeed, but it’s the pads that help expose the more pins on teensy which keeps its slim form factor. Even the 4.0 if it were to break out all the pins you would probably have a big form factor, ive been using the quad row i soldered up to my test bench teensies and i constantly swap them on breadboards all the time while writing libraries, i use the pad areas (SPI2) when i program for spi interface as it has an aligned set of pads for the bus. none of the pads failed because theyre reinforced by neighboring pinholes and pads

  8. #8
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    I think I must be misunderstanding. I love the pads, I am asking if it would be possible or in any way detrimental to slightly alter the circuit board traces that lead to the pads so if one accidentally rips off it is easier to repair. I do not want to alter anything about the pads themselves when they are correctly intact.

  9. #9
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    When I solder wires to the pads, I use slightly longer wires so the wires to the holes hopefully are the ones that take up any load, unless a specific wire is pulled.

    What I really think would be a good idea for the Teensy 4 is to have at least one 32bit word wide port with control lines where at least the first 8 to 16 bits are clear of any special functions like the first two to three instances of any serial port type, high resolution DAC or ADC ports, etc. +++ If the port has an input buffer that can hold a reasonable amount of data before overflowing, or has the ability for DMA to write incoming data strobed in by an outside source to a buffer in memory. DMA out is also needed, but that is usually implemented. I've seen the incoming DMA ability absent on many chips. It seams like a natural complement to outgoing DMA.

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