5 MCU+HHKB Power Comsumption
6 --------------------------
15 HHKB key switch power control
16 -----------------------------
17 MOS FET Nch: BSS138 or IRLML6344T, either works and no apparent difference.
18 Normally on(pull-up) or off(pull-down)? interms of power saving it prefers pull-down?
20 Pull-down will be better for power saving, normally off.
29 1) 16MHz xtal with system prescaler div2: F_CPU=8MHz, F_USB=16MHz
30 2) 8MHz xtal with div1: F_CPU=8MHz, F_USB=8MHz
31 Hardware USART doesn't work at 115200bps with 8MHz(F_CPU).
34 a) use Sotwre serial for communcation with RN-42
35 b) reduce baud of RN-42 to lower rate;(factory default is 115200bps)
54 SW,0320 Very sluggish. Type is not lost but very slow to register.
55 SW,0160 Still sluggish. may transposed? can type but ...
56 Mouse point move intermittently
57 SW,0020 feel a bit late like stumble(20ms)
58 SW,0010 feel no latency(10ms)
73 S%,1000 status led and connection control don't work
75 GPIO6: Connection control