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EN 48
7.
Q548.1E LA
The SPI bus is a synchronous serial data link standard that
operates in full duplex mode.
For debugging purposes, the working principle is given below:
•
At startup the controller will read-out matrix data from the
EEPROM devices (via SPI DATA RETURN)
•
Before operation, the driver current is set via SPI, with
driver in DC mode
•
During normal operation the controller receives RGB-,
configuration-, operation mode- and topology data via I
•
The controller converts the I
to SPI LED data
•
Via data return the controller receives error data (if
applicable).
Am b ilig h t m o d u le 1
L E D
D R IV E R
1
A R M
The ARM controller communicates with the LED drivers (on
each AL module) via an SPI bus. For debugging purposes, the
working principle is given below:
•
Data from the ARM controller is linked through the drivers,
which are connected in cascade
•
SPI CLK, SPI LATCH, PROG, BLANK and PWM CLOCK
are going directly from the controller to each driver
•
SPI DATA RETURN is linked from the last driver to the
controller: controller decides which driver returns data.
7.8.3
Temperature Control
Refer to
Figure 7-17
for signal interfacing between the ARM
controller and the temperature sensor on the AL boards.
Am bilight m odule 1
V c c
Pull-up
T E M P
S E N S O R
ARM
Figure 7-17 Communication between ARM controller and
temperature sensor
2009-Apr-03
Circuit Descriptions
2
C RGB data via the matrixes
S o ut
S in
SPI d ata return
SPI c lo c k (SC LK)
SPI latc h (XLAT )
PR O G (VPR G )
BLAN K
PW M C LO C K ( G SC LK)
Figure 7-16 SPI communication between ARM controller and LED drivers
Am bilight m odule 2
Am bilight m odule N
V c c
V c c
Pull-up
T E M P
T E M P
S E N S O R
S E N S O R
18310_206_090318.eps
Also PWM clock and BLANK signals are generated by the
controller. The controller can be reprogrammed via I
USB). The controller can receive matrix values via I
will be stored in the EEPROM of each AL module via the SPI
bus. The temperature sensor in each AL module controls the
TEMP line; in case of a too high temperature the controller will
reduce the overall brightness.
7.8.2
LED driver communication (via SPI bus)
2
C
Refer to
ARM controller and the LED drivers on the AL boards, and the
LED drivers and the EEPROMs on the AL boards.
A m b ilig h t m o d u le 2
S o ut
L E D
D R IV E R
2
Each AL board is equipped with a temperature sensor. If one of
the sensors detects a temperature over the threshold, the
TEMP line is pulled LOW which results in brightness reduction.
Pull-up
090318
Figure 7-16
below for signal interfacing between the
A m b ilig h t m o d u le N
S in
S o ut
L E D
D R IV E R
N
18310_205_090318.eps
2
C (via
2
C, which
090318
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