Manchester code (phase encoding) library.
Dependents: Manchester_Transmitter Manchester_Receiver
Manchester code (phase encoding) library
It implements Manchester code according to both IEEE 802.3 and G.E. Thomas' conventions.
- A '0' is expressed by a high-to-low transition, a '1' by low-to-high transition in the IEEE 802.3 convention. The reverse is true in the G.E. Thomas' convention.
- The transitions which signify '0' or '1' occur at the midpoint of a period.
- Transitions at the start of a period are overhead and don't signify data.
- Least significant bit is sent first
- There are synchronization pulses (the number can be set) at the begin of transmission
Select a convention to be used by commenting or uncommenting the line below in theManchester.h
header file.
Manchester.h
#define G_E_THOMAS 1
The IEEE 802.3 convention is used by default.
A Manchester encoded message (using G.E. Thomas' convention), with one sync pulse in the preamble, carrying four bytes:
ACKNOWLEDGEMENT: The code in this library was based on this article published by Robert Guastella.
Import programManchester_Transmitter
Manchester transmitter demo.
Import programManchester_Receiver
Manchester receiver demo.
NOTE: To perform a simple test (without radio modules) connect the txPin on transmitter board to the rxPin on the receiver board and make sure that grounds are also connected one another.
Diff: Manchester.h
- Revision:
- 5:3b2c7e9fda3f
- Parent:
- 2:de778df5892c
- Child:
- 6:7454ad91f714
diff -r f2c392191c74 -r 3b2c7e9fda3f Manchester.h --- a/Manchester.h Thu May 18 13:37:21 2017 +0000 +++ b/Manchester.h Sun May 21 19:17:28 2017 +0000 @@ -26,12 +26,31 @@ along with this program. If not, see <http://www.gnu.org/licenses/>. */ +/* + This library implements Manchester code according to both IEEE 802.3 + and G.E. Thomas' convention. + • A '0' is expressed by a high-to-low transition, a '1' by low-to-high transition + in the IEEE 802.3 convention. The reverse is true in the G.E. Thomas' convention. + • The transitions which signify 0 or 1 occur at the midpoint of a period. + • Transitions at the start of a period are overhead and don't signify data. + • Least significant bit is sent first + • There is one synchronization pulse at the begin of transmission + + The IEEE 802.3 convention is used by default. + Select a convention to be used by commenting or uncommenting + the line "#define G_E_THOMAS 1" below. +*/ + #ifndef MANCHESTER_H #define MANCHESTER_H #include "mbed.h" #include "ManchesterMsg.h" + +//Uncomment the following line to use G.E.Thomas' convention +//#define G_E_THOMAS 1 + class Manchester { enum State @@ -53,8 +72,8 @@ ( PinName txPin, /* transmitter pin name */ PinName rxPin, /* receiver pin name */ - uint32_t speed = 1200 /* speed in bits per second */, - uint8_t tol = 20 /* pulse width tolerance (+/-) in % */ + uint32_t speed = 1200, /* speed in bits per second */ + uint8_t tol = 25 /* pulse width tolerance (+/-) in % */ ); ~Manchester(void) { } void transmit(ManchesterMsg& msg);