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Member Since: October 27, 2012

Country: United States

  • According to a comment on the page for the larger version, its reported dimensions are external and so I would presume the same holds true here. The descriptions for both products do mention that the thickness of the walls is 2mm (although the commenter on the dimensions mentioned 'around 2.2mm'), and so by doing the math, this means the internal dimensions here are (approximately) either 110x59x29mm or a tad bit less. In my opinion, such discrepancies shouldn't matter too much if you can get the enclosure before finalising any design. When putting a rough sketch together, very exact precision down to the millimetre would only be truly needed if one were to be really cramming a lot of components inside, which isn't generally advisable in any situation, especially the first iteration.

    A final word of advice: the dimensions shown by the pictures don't quite match the descriptions in any case, one reason to contact customer support to clarify if such information is absolutely crucial, though in prototyping it typically shouldn't be.

  • Overall, this looks like a great product. Making such a large array in a small package with just eight IOs is a fantastic idea. However, the lack of contrast between the red light of the LEDs and the bright red silkscreen appears to be a drawback.

    To my eyes, when looking at both the pictures provided and the showcase video, it's difficult to discern the lit from the unlit LEDs. In the video, even when the ambient light is turned down somewhat, the array is still not quite distinctive enough. I can understand the reasons: red LEDs are typically cheaper, power consumption versus brightness is an issue and, being a Sparkfun product, it's natural to make the silkscreen red for both branding and cost. If it is going to be operated in at least near darkness or some kind of contrasting cover to shine through is used, then I suppose my concerns are probably irrelevant. Otherwise, I think changing the colour of either the silkscreen or the LEDs should be considered to make it a more useful product.

  • I sort of doubt it could even do 120V. Perhaps someone who's pried it apart could tell us, but I suspect it's got a simple micro switch inside. Keyboards obviously use fairly low DC voltage and a quick search will reveal that the tattoo machines that are mentioned above use at most something like 18V. I would recommend, and I think I'm going to try it myself, to use this to switch a relay. There might be a small delay and a separate battery (or transformer, though that would be kind of wasteful) would be necessary, but those inconveniences shouldn't be a problem for something like a Dremel.

  • for Mac: alt(option) + z(lower case) = Ω

  • The description says it has a nozzle diameter of 5mm. Is that in reference to the hole at the end of the tip?

  • If that's the case, please correct the features for the locking versions which says '(1NO1NC/2NO2NC)'. The voltage drop on the LEDs would be nice, too, in case 5V isn't handy — a regulator seems a bit much for one LED. Thanks.

  • The features describe the operation as having two NO contacts and two NC contacts: 1NO1NC/2NO2NC. However, in the comments section of the momentary red switch, RobertC.'s description implies there is only one circuit when he says of the pins

    three are for the switch and two are for the LED

    which is what I would have assumed without any description. I know these things are really simple but a wiring diagram or just a better picture of the pins' labels would clear this up.

  • The datasheet does claim it's panel-mount ready but the real hitch for most hobbyists, of course, is manufacturing membranes for the buttons or designing a knob for the pot. That being said, as everything on this shield appears to be PTH, it would be fairly easy to remove the buttons, bring them to the case and use either jumper wires or a custom cable (perhaps after creating a small custom board for the buttons). This approach also enables replacement of the provided buttons with ones that better suit the needs of a build, for example, SFE's concave panel-mount buttons or their 5-way Tactile Switch. I would also imagine that the screen itself can be detached and replaced with any equivalent 16x2 that uses the HD44780 interface if a different colour is desired or a different orientation to the case is required. I believe all of SFE's 5V screens of that size would therefore work.

  • This could be a great fail-safe mechanism. If you assume there's only one key on hand with two switches (or another number based on some other pattern of multiple switches) and you altered the holes to lock the keys in, either open or closed, then you could restrict whether one switch could be flipped based on the position of the other one.

    This is the same type of logic used in industrial safety systems e.g. until you turn on the cooling system, you can't remove the very same key required to turn on the reactor core and while the core is running, you can't remove the key, preventing the cooling system from being turned off and protecting the system.

  • The idea behind these is that most people don't have any kind of tool regularly on hand which could turn this switch. That makes this a relatively secure switch mechanism whereas the other key switch SparkFun offers is more of a novelty because it can be turned fairly easily with a screwdriver or something similar.

    Therefore, I would classify this as more tamperproof than secure. The average person who encounters won't be able to engage it but don't use it where anything too tempting is at stake.

No public wish lists :(