keyboard/hhkb/rn42/PowerSave.txt

   1 Power Saving
   2 ============
   3
   4
   5 MCU+HHKB Power Comsumption
   6 --------------------------
   7 Battery drive:
   8     idle    18.9mA
   9     active  35.8mA
  10
  11 USB powered:
  12     40.0mA
  13     52mA    01/17
  14
  15 Other keyboards:
  16 HHKB Pro    55mA
  17 HHKB Pro2   140mA
  18 HHKB Pro    42mA(Alt)
  19 HHKB Pro2   52mA(Alt BT controller USB mode)
  20 HHKB Pro2   88mA(Alt BT controller BT mode connected)
  21 HHKB Pro2   68mA(Alt BT controller BT mode config mode)
  22 Poker X     6mA
  23 Infinity    24mA(TMK)
  24             65mA(kiibohd)
  25
  26
  27 HHKB key switch power control
  28 -----------------------------
  29 MOS FET Nch: BSS138 or IRLML6344T, either works and no apparent difference.
  30 Normally on(pull-up) or off(pull-down)? interms of power saving it prefers pull-down?
  31
  32 Pull-down will be better for power saving, normally off.
  33
  34
  35
  36 Used Timer
  37 ----------
  38
  39 8MHz clock
  40 ----------
  41 1) 16MHz xtal with system prescaler div2: F_CPU=8MHz, F_USB=16MHz
  42 2) 8MHz xtal with div1: F_CPU=8MHz, F_USB=8MHz
  43 Hardware USART doesn't work at 115200bps with 8MHz(F_CPU).
  44
  45 workaround:
  46 a) use Sotwre serial for communcation with RN-42
  47 b) reduce baud of RN-42 to lower rate;(factory default is 115200bps)
  48 10/03
  49
  50
  51
  52 Slave mode
  53 ----------
  54 Discovery/Inquire
  55 Connect/Page
  56
  57 SI,0012
  58 SJ,0012
  59 InqWindw=0100
  60 PagWindw=0100
  61
  62
  63 Sniff mode
  64 ----------
  65 0.625ms * <hex>
  66 SW,0320     Very sluggish. Type is not lost but very slow to register.
  67 SW,0160     Still sluggish. may transposed? can type but ...
  68             Mouse point move intermittently
  69 SW,0020     feel a bit late like stumble(20ms)
  70 SW,0010     feel no latency(10ms)
  71
  72
  73 Deep sleep
  74 ----------
  75 SW,8010
  76
  77
  78 TX power
  79 --------
  80 SY,fff4
  81
  82
  83 IO pins
  84 -------
  85 S%,1000         status led and connection control don't work
  86                 GPIO5: status LED
  87                 GPIO6: Connection control
  88                 GPIO2: linked status