Microchip Technology AC164145 User Manual
Utility-band BPSK 6.0 kbps PLM PICtail™ Plus Daughter Board User’s Guide
DS75019A-page 26
© 2011 Microchip Technology Inc.
Each frame (of 128 byte length) is composed of 16 bytes of preamble, 110 bytes of data
and 2 bytes of CRC. The demonstration application has two LCD views, which can be
toggled using switch S3 on the Explorer 16 Development Board:
• Frame statistics
• Application configuration (carrier frequency, modulation and baud rate)
and 2 bytes of CRC. The demonstration application has two LCD views, which can be
toggled using switch S3 on the Explorer 16 Development Board:
• Frame statistics
• Application configuration (carrier frequency, modulation and baud rate)
3.2.2
Sensor Monitoring Demonstration
This demonstration implements a network protocol with framing, CRC and a network
stack framework.
stack framework.
The demonstration consists of a base station and a number of nodes.
Each node measures its potentiometer state (R6 on the Explorer 16 Development
Board) and sends the result to the station. The station displays the received values on
the LCD screen.
1. Program one Explorer 16 Development Board with the Station software.
2. Program one or more Explorer 16 Development boards with the Node software
Board) and sends the result to the station. The station displays the received values on
the LCD screen.
1. Program one Explorer 16 Development Board with the Station software.
2. Program one or more Explorer 16 Development boards with the Node software
(each node must have a unique MAC address and must know the station MAC
address).
address).
3. Connect all boards to the power line and they will automatically start to
communicate.
4. Turn the potentiometer, R6, on a node board. Observe how the value is updated
on the node and station LCD screens.
5. Use the S3 button to change the LCD screen contents. The LCD can display the
current potentiometer state and packet statistics (frames transmitted, frames
received and errors).
received and errors).
Debug information is sent via the serial port. The output can be observed by connecting
a serial port emulator (such as HyperTerminal) to the RS-232 port of the Explorer 16
Development Board. The UART configuration for this demonstration is:
• 115200 bps
• 8-N-1
• No flow control
a serial port emulator (such as HyperTerminal) to the RS-232 port of the Explorer 16
Development Board. The UART configuration for this demonstration is:
• 115200 bps
• 8-N-1
• No flow control
3.2.3
Pipe Demonstration
This demonstration implements a raw data pipe for UART-to-UART connection over the
power line.
1. Connect a sender application (a PC or an embedded device) to the RS-232 port
power line.
1. Connect a sender application (a PC or an embedded device) to the RS-232 port
of an Explorer 16 Development Board and a receiver application to the RS-232
port of the other Explorer 16 Development Board.
port of the other Explorer 16 Development Board.
2. The sender application may start transmitting data.
Data is immediately transferred over the power line and received by the receiver.
Sender and receiver may change roles at runtime. One-to-many configurations are
also valid.
The link is designed to appear raw and unframed to both RS-232 devices. Internally,
however, simple framing is used. Its purpose is to ensure that the receiver maintains
byte synchronization. Without framing it would not be practically feasible to guarantee
that the receiver and transmitter are byte-aligned. A frame consists of 10 preamble
characters (PRE = 0x2A), one Start of Frame character (SOF = 0x1B), a length byte,
up to 64 payload bytes, and a 16-bit ITUT CRC checksum. In total there is a 14 byte
overhead for each frame.
Data is immediately transferred over the power line and received by the receiver.
Sender and receiver may change roles at runtime. One-to-many configurations are
also valid.
The link is designed to appear raw and unframed to both RS-232 devices. Internally,
however, simple framing is used. Its purpose is to ensure that the receiver maintains
byte synchronization. Without framing it would not be practically feasible to guarantee
that the receiver and transmitter are byte-aligned. A frame consists of 10 preamble
characters (PRE = 0x2A), one Start of Frame character (SOF = 0x1B), a length byte,
up to 64 payload bytes, and a 16-bit ITUT CRC checksum. In total there is a 14 byte
overhead for each frame.