Intermec CK30

Chapter 4 — Theory of Operation
Where
[ack]
= ACK from PXA255,
[nak]
= NAK from PXA255
Hex Command Return Data
0x10 SetLowBatLED 0x10
0x11 ClearLowBatLED 0x11
0x12 PSCSoftwareVer 0x12 + PSC firmware version byte
0x30 ReadMainBatVoltage 0x30 + main battery voltage byte
0x40 ReadSuperCapVoltage 0x40 + supercap voltage byte
0x50 ReadTemperature 0x50 + temperature byte
0x5A PSCTest 0x5A
0x60 ColdBoot 0x60
0x61 WarmBoot 0x61
0x70 SuperCapChargeEnable 0x70
0x71 SuperCapChargeDisable 0x71
0x80 StartLowBatLEDFlash 0x80
0x81 StopLowBatLEDFlash 0x81
Several commands can be issued in a single burst before the host I2C
driver attempts to read return values back from the PSC.
Examples:
([W] = Write, [R] = Read, [A] = Ack, [N] = Nak)
A typical battery/supercap/temperature status request:
[Start]#12[W][A]30[A]40[A]50[A][Start]#12[R][A]30[A]95[A]
40[A]E1[A]50[A]56[N][Stop]
A warm boot command followed by a battery/supercap/temperature status
request:
[Start]#12[W][A]61[A][Start]#12[W][A]30[A]40[A]50[A]
[Start]#12[R][A]61[A]30[A]97[A]40[A]E0[A]50[N][Stop]
Battery Status Monitoring
Main battery voltage under load is scaled through operational amplifiers
U41, sampled through the PSC A/D converter, and made available to
system power management software for accurate on-display fuel gauging
and device power management in the low-battery operating region.
Reference D14 and operational amplifiers U41 provide the reference
voltage for the PIC A/D. The PSC sends raw A/D data over the I2C bus
in response to I2C commands sent approximately every 3 seconds from the
power management software running on the PXA255 (See “PSC 12C
Syntax” on page 59).
CK30 internal temperature is sensed by thermistor RT3, read through a
PSC A/D, and sent to the OS over the I2C bus in response to I2C
command.
60 CK30 Handheld Computer Service Manual