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Platform3 (testing prototype)

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  • RaymanRayman Posts: 16,010

    Actually there's Schottky diode right there so tried powering after that, ~4.8 V.
    That worked color wise, but battery bank still turned out.
    Going to see if two WS2816B is enough...

  • RaymanRayman Posts: 16,010
    edited 2026-01-27 14:42

    Found that two WS2816B LEDs in white draws enough current to keep the battery pack on.

    Tried reducing the on time to conserve power.. 50% duty like below works, but less than that doesn't seem to work...

    PUB Main | pos
    
      strip.start_b(LEDS, STRIP_LEN)                                ' start led driver
      strip.off
    
      repeat
        strip.set_all(strip#white)
        pause(5000)
        strip.set_all(strip#BROWN)
        pause(5000)
    
  • maccamacca Posts: 983

    @Rayman said:
    Was hoping that cheap USB keyboards would support PS/2 mode, but the two tested just now didn't work.

    [...]

    Anyway, going to go forward with dual USB wired for PS/2 instead of real PS/2 just because is smaller and looks better.

    Just in case you missed it, there is a USB driver for the P1 https://github.com/SaucySoliton/propeller-usb-host

  • RaymanRayman Posts: 16,010

    Thanks @macca that looks better than last time I looked at it. Still, main problem there is that I/O pins have to be in 0..7 range.
    Doesn't work in this particular instance...

  • JonnyMacJonnyMac Posts: 9,631

    In a very large number of my P1 projects a launch an internal support cog that runs a 1ms loop and calls very tasks that have their own timing variables. It turns out that you can get quite a lot of work done in a millisecond in the P1. This might be something to consider for your controller -- you're trading one cog (WS28xx) for this; that said, you can control a standard LED and a whole lot more, and use the LED as a 1s "heartbeat" indicator.

    This is the background code in the demo.

    con { background cog }
    
    var
    
      long  bcog                                                    ' background cog #
      long  bcstack[32]                                             ' stack for background cog
    
      long  millis                                                  ' global milliseconds register
    
    
    pri background | t                                              ' launch with cognew()
    
      io.low(LED_26)
    
      millis := 0
    
      t := cnt                                                      ' sync loop timer
      repeat
        waitcnt(t += MS_001)                                        ' run loop every millisecond
        ++millis                                                    ' increment millis
        show_heartbeat
    
    
    var
    
      long  hbms
    
    
    pri show_heartbeat
    
      if (++hbms == 1000)
        hbms := 0
    
      if (hbms < 250)
        outa[LED_26] := 1                                           ' 100%
    '   outa[LED_26] := hbms                                        '  50%
    '   outa[LED_26] := hbms >> 1                                   '  25%
      else
        outa[LED_26] := 0
    
  • RaymanRayman Posts: 16,010

    @JonnyMac Something to keep in mind...

    @macca Will see if can add pads for pulldowns so could then use for real USB using jumpers at least...

  • RaymanRayman Posts: 16,010

    Here's layout for VGA-PS2(on USB)-stereo-mic board, adapted from P2 version. Same size, but this one has a lot more resistors and caps...

    911 x 1148 - 143K
  • @Rayman said:

    The easy way around this is to put two 100 Ohm resistors between 5V and ground. This seems to suck enough power to keep my bank on. Not sure how universal that is going to be though.
    Still think will add this with another solder jumper. Definitely don't want that connected when powering board by coil cell...

    Might look to see if there's another load that would keep it going. Maybe a couple NeoPixels would be enough. Robot needs lights anyway...

    Hi, I recently read that it is enough, to have a current pulse load to keep the power bank on. It isn't necessary to have a constant load. Current and pulse frequency varies for different banks.

  • RaymanRayman Posts: 16,010

    @"Christof Eb." Read that too. But, doesn't really work with one of my power banks. Anything less than 50% duty load and it shuts down. But, maybe need to play with that more....

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