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  1. rq3

    adc resolution on picaxes, down to 100mV

    Years ago I delved deeply into why the manufacturer of the base chip said not to do this, and never got a satisfactory answer. However, there is an errata sheet that says if you DO use a lower internal reference voltage, you should "step in to it", rather than invoke it in one fell swoop. Using...
  2. rq3

    PC board fabs

    The original intent of my post was to point out that a part 3D printed out of 316 stainless steel may not meet expectations, and is a really nasty thing to post machine. But the experiment was well worth the price ($11 including shipping) from JLCPCB, who apparently do a very good job with...
  3. rq3

    PC board fabs

    Basically, because it's part of the fascination. My go-to printer is a delta design, currently with 5 micron resolution for each axis. Even the ambient temperature is important.
  4. rq3

    PC board fabs

    I had a part 3D printed in 316 stainless steel by JLCBCB, using the same STEP file I had used to fabricate the same part using CNC machining by hubs.com. The printed part got here much faster than expected, and looked great. BUT. The tolerances in the important axes were way off (I'm chasing...
  5. rq3

    Power Supply Integration

    It's important to note the series diode on the regulator input of these schematics. When using a large (greater than 10uF) output capacitor on most small linear regulators (7805 and the like), if you short the regulator input, the large cap will discharge in reverse through the regulator...
  6. rq3

    PC board fabs

    In my case, they did flag an area that effectively goes to a sharp edge and is probably not printable, but is machinable. The edge is not important, and I authorized the print. It will be interesting to see what I get. I've had no issues printing the part in various plastics, but 316 stainless...
  7. rq3

    PC board fabs

    Me too. I bit the bullet and ordered the $8 stainless steel part from an existing STEP file last week. In on-line chat just now, they indicated that the file has been sent to the engineer for review, but it's early morning there. From what I know of Chinese New Year, he may not be in a condition...
  8. rq3

    PC board fabs

    Here are descriptions of somewhat incestuous enclosures and circuits (the 3D printer is printing parts for itself). But they do use Picaxes. In one case, the enclosure had to be opaque. In the other, it had to be translucent.
  9. rq3

    PC board fabs

    I've had several small parts CNC machined from aluminum by hubs.com. In quantities of 5, they cost about $60 each. JLCPCB will print them in stainless steel for $8 each. I'm tempted, despite the weight.
  10. rq3

    Linear Tracking Turntable

    Not an audiophile, but your intriguing project had me looking though the old Columbia Microgroove information, which as far as I can tell is THE standard for 33-1/3 RPM LP mastering to this day, except for very rare and outlier pressings. The disc is 30 centimeters in diameter, turns at...
  11. rq3

    Random youtube video, Can picaxe do this?

    Yes, Picaxe can do this. Each touch area would be a fairly large (several square centimeters, the bigger the better) area of metal under an epoxy coat or sheet of glass. The touch sensitivity can be adjusted anywhere from a firm press with a wet finger, to waving your hand 6 inches above the...
  12. rq3

    Editor Fonts

    Thank you!
  13. rq3

    Editor Fonts

    Is there a way to add fonts to PE6, other than the default choices? I noticed that I can edit the settings.xml file to use "Tahoma" rather than "Courier New", and it works. But only once, and only if you don't change the font size.
  14. rq3

    Auto-sense whether a pin should be ADC or serial-input

    It is possible to apply an internal "weak pullup" to an ADC input pin, and then use the switched resistor chain from the ADC pin to ground to get various ADC readings. The only gotcha is that the weak pullup value can be all over the map, so you'd have to select the values in the resistor chain...
  15. rq3

    Are >= and <= valid?

    Thank you Sir!
  16. rq3

    Are >= and <= valid?

    The compiler doesn't complain, but they are not listed in the BASIC commands. For example: loop until w0>=10 or if w1<=20 then
  17. rq3

    Pogo Pin Programming

    I kind of like the idea of adding a power Pogo as the fourth pin. It would solve the "polarization" issue, but would make a hard reset problematic.
  18. rq3

    Pogo Pin Programming

    Me too. And even with a surface mount picaxe, the pogo needles don't hit the Picaxe with 0.025 inch through holes on a standard 1/16 inch thick board.
  19. rq3

    Pogo Pin Programming

    I don't press the Pogo pins in contact with pads. That would be nasty. I place 3 through holes on the board so that the Pogo pins go through, and stay in place during programming without having to hold the Pogo adapter. At 0.1 inch spacing, the Pogo pins also match Perf and Proto boards. I can't...
  20. rq3

    Pogo Pin Programming

    Sometimes a Molex KK is appropriate to the PCB design, so I can just unplug the Pogo adapter, and plug the KK on to the board.
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