User Manual

9
Detailed Description
Gesture detection, proximity detection, and RGBC color
sense/ambient light sense functionality is controlled by
a state machine, as depicted in Figure 12, which recon-
gures on-chip analog resources when each functional
engine is entered. Functional states/engines can be in-
dividually included or excluded from the progression of
state machine ow. Each functional engine contains con-
trols (E.g. Gain, ADC integration time, wait time, persis-
tence, thresholds, etc.) that govern operation. Control of
the Led Drive pin, LDR, is shared between Proximity and
Gesture functionality. The color/ALS engine does not use
the IR LED, but cross talk from IR LED emissions during an
optical pattern transmission may aect results.
The operational cycle of the device for Gesture/Proximity/
Color is as depicted in Figure 6 and Figure 7.
Upon power-up, POR, the device initializes and immedi-
ately enters the low power SLEEP state. In this operational
state the internal oscillator and other circuitry are not
active, resulting in ultra-low power consumption. If I²C
transaction occurs during this state, the oscillator and I²C
core wakeup temporarily to service the communication.
Once the Power ON bit, PON, is enabled, the internal os-
cillator and attendant circuitry are active, but power con-
sumption remains low until one of the functional engine
blocks are entered. The rst time the SLEEP state is exited
and any of the analog engines are enabled (PEN, GEN, AEN
Figure 6. Simplied State Diagram
Figure 7. Detailed State Diagram
=1) an EXIT SLEEP pause occurs; followed by an immedi-
ate entry into the selected engine. If multiple engines are
enabled, then the operational ow progresses in the fol-
lowing order: idle, proximity, gesture (if GMODE = 1), wait,
color/ALS, and sleep (if SAI = 1 and INT pin is asserted).
The wait operational state functions to reduce the power
consumption and data collection rate. If wait is enabled,
WEN=1, the delay is adjustable from 2.78ms to 8.54s, as
set by the value in the WTIME register and WLONG control
bit.
PROX
IDLE
GESTURE
WAIT
COLOR
ALS
SLEEP
Gesture, Proximity
Color/ALS
State Machine
POR
INITILIZE
(5.7 ms)
SLEEP
IDLE
EXIT SLEEP
(7 ms)
GESTURE
ENGINE
PROXIMITY
ENGINE
COLOR
ENGINE
WAIT
(0 – 8.5ms)
PON == 1 ?
PEN ||
GEN ||
AEN == 1 ?
SAI == 1
&& INT
PIN == 0 ?
AEN == 1 ?
GEN ==
1 &&
GMODE
== 1 ?
Operational States
Y
N
YN
Y
N
N
Y
N
Y
PON = 1
PEN = 1
AEN = 1
GEN = 1
GMODE = 0 / 1
PEN = 0
AEN = 1
GEN = 0 / 1
GMODE = 0
PEN = 1
AEN = 0 / 1
GEN = 0 / 1
GMODE = 0
PEN = 1
AEN = 0 / 1
GEN = 1
GMODE = 1
GMODE is set by host
GMODE is set
by Prox