SE-8008 Sensor
extender
Keyword:
INHAOS , Arduino , Smart Car , UGV , MassDuino ,
SE-8008
l Introduce
The
SE-8008 is a sensor expansion board based on MassDuino , the main chip is
MD-8088. MD-8088 integrates a wealth of digital peripherals and analog
peripherals, it offers
great flexibility and play space for the users of the product design. SE -8008
is using SPI to communicate with main processor, it can save a lot of ports, so
that we can use the SE-8008 to extend more different sensors from the main
system. If you have a need, in this way can also extend other modules from the
control board, such as the LE-1600 , RC-1406(Mortor Driver), ADC acquisition
module and so on. MD-8088 chip is editable in the Arduino environment, so we
can use a USB to serial cable for SE-8008 for upgrade firmware. The module is
high performance low power, low cost , and it support secondary development.
l Features
Ø Can
be program in the Arduino environment, very easy to use
Ø Support
secondary development
Ø 8K
bytes of in-system programmable FLASH, innovative data encryption technology
Ø 504
bytes of data FLASH, support byte read (simulate E2PROM)
Ø 1K
SRAM bytes on-chip
Ø Programmable
synchronous / asynchronous USART
Ø Can
work in master / slave mode SPI Serial Interface
Ø I2C
-compatible two-wire serial communication interface protocols , supporting
master and slave device mode
Ø 32
8it general purpose working registers
Ø Support
the expansion of the chip in-circuit debugging functions
Ø By
SWD interface programming for FLASH, EEPROM, system configuration area , the
ISP function
Ø Up
to 30 programmable I / O
Ø High-performance,
low -power and low-cost
l SPI communication
ports
When
we use the SE-8008, we can use the DuPong cable to connect it to the master
chip SPI communication port.
l SPI Protocol
The SE-8008 was working in SPI Slave mode , after power on , the
chip will wait for command
form SPI Master ,then implement it if the it
received valid command.
The communication protocol as below:
In the master side , the SPI initial code as below:
SE-8008 supported command as below:
l IR Sensor
Connection
Below figure show the connection between IR sensor and SE-8008,
they are connected via 3 wires: TX / RX and GND.
SENSOR_IR_OFF: the TX
will set to "0", the IR will turned off , then read RX by 10bit ADC ,
this is the background IR signal.
SENSOR_IR_ON: the TX will set to "1", the IR will
turned ON, then read RX by 10bit ADC , the signal level depend on the distance
of obstacles.
SENSOR_IR_DIFF: the
difference between SENSOR_IR_OFF and SENSOR_IR_ON. most IR detector use
comparator to shaping the signal with a fixed reference level, when we use IR
to detect distance of obstacles , the result is very depends on the environment
, for the example , some time the unit is working very good in room , but when
you turned light or move to sunlit environment, it will occurred unexpected
error , because the light or sunshine have very high IR signal , this will
change the background level and make the IR detector working failed. In this
case , you can read SENSOR_IR_DIFF , this value will significantly reduce the
environment changes impact the detection result.
l Photo interrupter
Connection
The SE-8008 include 8-CH of IR detection and 2-CH of Photo
interrupter, the IR detection used to detect distance of obstacles and photo
interrupter used to detect wheel rotation speed, Below figure show the photo
interrupter connection and how it work.
Difference with the IR detection circuit, the IR is always powered
, and the OPT signal will shaping by a comparator, thinking difference
application have difference signal level , so adjust the 10K VR to adjust
reference level of the comparator.
l Arduino Source
Code
Two code will coming with this board:
1, SE-8008.rar
This is arduino source code for SE-8008 ,
to development the SE-8008 , user need to install
MassDuino driver, and write
code in arduino , and upload sketch via USB2SERIAL light cable,
the relational
link as below:
2, SE-8008_UNO_MASTER.rar
This
is arduino source code for UNO , the UNO will working with SE-8008, this code
demo
how to use SE-8008 in Arduino.
All code can be download from www.inhaos.com
l Application:
n Extend IO and save code for UNO to drive many sensors
n Arduino car / robotics
n Sensor drive
n Toy