Can FPGA used to control powerline communications.

Altera_Forum · ‎10-08-2011

Can anyone help me on this ...i would like to use fpga to be used on powerline communication but im blank on how to do it......

Altera_Forum · ‎10-08-2011

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Can anyone help me on this ...i would like to use fpga to be used on powerline communication but im blank on how to do it......

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You'll need some sort of PHY (physical interface).

Go and find out how microcontrollers do it. The interface will be some form of parallel/serial I/O to the PHY, and then the PHY will connect to the power-line. Most likely through an isolating transformer.

Google it:

http://en.wikipedia.org/wiki/power_line_communication

http://www.cypress.com/?id=2330

http://www.maxim-ic.com/datasheet/index.mvp/id/7099

http://www.st.com/internet/imag_video/subclass/923.jsp

Cheers,

Dave

Altera_Forum · ‎10-09-2011

I've found an article on powerlines which uses PIC 16F877A....by any chnce can i knoe which fpga can be compatible to replace PIC 16F877A where it can be used to transmit and receive data....further it can read parallel data and convert it to serial data....ive attached the circuit to be more precise....

Altera_Forum · ‎10-09-2011

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I've found an article on powerlines which uses PIC 16F877A....by any chnce can i knoe which fpga can be compatible to replace PIC 16F877A where it can be used to transmit and receive data....further it can read parallel data and convert it to serial data....ive attached the circuit to be more precise....

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This is just one method of powerline communications.

If you plan on connecting two devices together of your own design, then you can use something like this. However, if you expect to interface to other commercial components, then you have to select a standard PLC interface (there will be multiple). So first, decide what you want to communicate with, then find a compatible PHY.

Cheers,

Dave

Altera_Forum · ‎10-11-2011

i would like to use this method ...can u suggest me the right fpga that i can use....and few tutorials sites where i can learn on writing verilog coding for this applications

Altera_Forum · ‎10-11-2011

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i would like to use this method ...can u suggest me the right fpga that i can use....

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The paper indicates the carrier and data rate:

"rectangular waveform with frequency of 140 KHz which is much greater than the used data baud rate (500 bit/s)"

So literally any FPGA can be used.

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and few tutorials sites where i can learn on writing verilog coding for this applications

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Use Google. Use the tutorials that come with Modelsim, Quartus, and the University program code.

Cheers,

Dave

Altera_Forum · ‎10-12-2011

...if any fpga can be used ... i have a DE2 board which consist cyclone 2 ...can i use the board to test the likewise circuit..Any idea how the circuit looks like if i want to replace the PIC....Any suggestion on how can i write my coding as i am using verilog to do it.....

thnx

Alen:)

Altera_Forum · ‎10-12-2011

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i have a DE2 board which consist cyclone 2 ...can i use the board to test the likewise circuit..

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That would meet the requirement of 'any FPGA board'.

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Any idea how the circuit looks like if i want to replace the PIC....

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Look at the PIC circuit. Make sure you protect the FPGA I/O. Check that voltages are compatible. Add buffers where they are not. Simulate the analog circuit using LTSpice.

Try something out. If you use a buffer board between your DE2 and your test circuits, then the worst you can do is destroy the buffer board. Its time to roll up your sleeves and do something :)

Cheers,

Dave

Altera_Forum · ‎12-14-2011

how can i come across for the verilog coding as i am using the de-2 board ...how can i manipulate the rs232 pin to be the transmitter...

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Try something out. If you use a buffer board between your DE2 and your test circuits, then the worst you can do is destroy the buffer board

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and what type of buffer board can i prepare for this...

Altera_Forum · ‎12-14-2011

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how can i come across for the verilog coding as i am using the de-2 board ...how can i manipulate the rs232 pin to be the transmitter...

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Write a UART routine, or create an SOPC or Qsys System with a NIOS processor and include a UART in that system.

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and what type of buffer board can i prepare for this...

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Sparkfun and other sites have buffer boards with LS244/LS245 style buffers. Its really up to whatever your design requires. If you need high current drivers, then you might need a boost transistor.

Look in an electronics book.

Cheers,

Dave

Altera_Forum · ‎12-20-2011

I am going to build this part of the project which is the OOK modulator as shown

belowhttps://www.alteraforum.com/forum/attachment.php?attachmentid=5226

and i have to interface it with a another board using RS232 male connector soe that i can attach to my DE-2 board... by exactly following the circuit can i connect to the RS232 port in my DE-2 would it work?...ive tried using LT spice for simulation purposes since im not that good on using the software i found it hard to come up with the simulation ...i am preparin to do it practically...

and i have found a RS232 based verilog code in order to be test for the Tx and Rx...can this coding work for this powerline project...im connecting two ALTERA DE-2 boards using the powerline....any advise...

// RS-232 TX module
//`define DEBUG   // in DEBUG mode, we output one bit per clock cycle (useful for faster simulations)
module async_transmitter(clk, TxD_start, TxD_data, TxD, TxD_busy);
input clk, TxD_start;
input  TxD_data;
output TxD, TxD_busy;
parameter ClkFrequency = 25000000;	// 25MHz
parameter Baud = 115200;
parameter RegisterInputData = 1;	// in RegisterInputData mode, the input doesn't have to stay valid while the character is been transmitted
// Baud generator
parameter BaudGeneratorAccWidth = 16;
reg  BaudGeneratorAcc;
`ifdef DEBUG
wire  BaudGeneratorInc = 17'h10000;
`else
wire  BaudGeneratorInc = ((Baud<<(BaudGeneratorAccWidth-4))+(ClkFrequency>>5))/(ClkFrequency>>4);
`endif
wire BaudTick = BaudGeneratorAcc;
wire TxD_busy;
always @(posedge clk) if(TxD_busy) BaudGeneratorAcc <= BaudGeneratorAcc + BaudGeneratorInc;
// Transmitter state machine
reg  state;
wire TxD_ready = (state==0);
assign TxD_busy = ~TxD_ready;
reg  TxD_dataReg;
always @(posedge clk) if(TxD_ready & TxD_start) TxD_dataReg <= TxD_data;
wire  TxD_dataD = RegisterInputData ? TxD_dataReg : TxD_data;
always @(posedge clk)
case(state)
	4'b0000: if(TxD_start) state <= 4'b0001;
	4'b0001: if(BaudTick) state <= 4'b0100;
	4'b0100: if(BaudTick) state <= 4'b1000;  // start
	4'b1000: if(BaudTick) state <= 4'b1001;  // bit 0
	4'b1001: if(BaudTick) state <= 4'b1010;  // bit 1
	4'b1010: if(BaudTick) state <= 4'b1011;  // bit 2
	4'b1011: if(BaudTick) state <= 4'b1100;  // bit 3
	4'b1100: if(BaudTick) state <= 4'b1101;  // bit 4
	4'b1101: if(BaudTick) state <= 4'b1110;  // bit 5
	4'b1110: if(BaudTick) state <= 4'b1111;  // bit 6
	4'b1111: if(BaudTick) state <= 4'b0010;  // bit 7
	4'b0010: if(BaudTick) state <= 4'b0011;  // stop1
	4'b0011: if(BaudTick) state <= 4'b0000;  // stop2
	default: if(BaudTick) state <= 4'b0000;
endcase
// Output mux
reg muxbit;
always @( * )
case(state)
	3'd0: muxbit <= TxD_dataD;
	3'd1: muxbit <= TxD_dataD;
	3'd2: muxbit <= TxD_dataD;
	3'd3: muxbit <= TxD_dataD;
	3'd4: muxbit <= TxD_dataD;
	3'd5: muxbit <= TxD_dataD;
	3'd6: muxbit <= TxD_dataD;
	3'd7: muxbit <= TxD_dataD;
endcase
// Put together the start, data and stop bits
reg TxD;
always @(posedge clk) TxD <= (state<4) | (state & muxbit);  // register the output to make it glitch free
endmodule

and the receiver part

// RS-232 RX module
module async_receiver(clk, RxD, RxD_data_ready, RxD_data, RxD_endofpacket, RxD_idle);
input clk, RxD;
output RxD_data_ready;  // onc clock pulse when RxD_data is valid
output  RxD_data;
parameter ClkFrequency = 25000000; // 25MHz
parameter Baud = 115200;
// We also detect if a gap occurs in the received stream of characters
// That can be useful if multiple characters are sent in burst
//  so that multiple characters can be treated as a "packet"
output RxD_endofpacket;  // one clock pulse, when no more data is received (RxD_idle is going high)
output RxD_idle;  // no data is being received
// Baud generator (we use 8 times oversampling)
parameter Baud8 = Baud*8;
parameter Baud8GeneratorAccWidth = 16;
wire  Baud8GeneratorInc = ((Baud8<<(Baud8GeneratorAccWidth-7))+(ClkFrequency>>8))/(ClkFrequency>>7);
reg  Baud8GeneratorAcc;
always @(posedge clk) Baud8GeneratorAcc <= Baud8GeneratorAcc + Baud8GeneratorInc;
wire Baud8Tick = Baud8GeneratorAcc;
////////////////////////////
reg  RxD_sync_inv;
always @(posedge clk) if(Baud8Tick) RxD_sync_inv <= {RxD_sync_inv, ~RxD};
// we invert RxD, so that the idle becomes "0", to prevent a phantom character to be received at startup
reg  RxD_cnt_inv;
reg RxD_bit_inv;
always @(posedge clk)
if(Baud8Tick)
begin
	if( RxD_sync_inv && RxD_cnt_inv!=2'b11) RxD_cnt_inv <= RxD_cnt_inv + 2'h1;
	else 
	if(~RxD_sync_inv && RxD_cnt_inv!=2'b00) RxD_cnt_inv <= RxD_cnt_inv - 2'h1;
	if(RxD_cnt_inv==2'b00) RxD_bit_inv <= 1'b0;
	else
	if(RxD_cnt_inv==2'b11) RxD_bit_inv <= 1'b1;
end
reg  state;
reg  bit_spacing;
// "next_bit" controls when the data sampling occurs
// depending on how noisy the RxD is, different values might work better
// with a clean connection, values from 8 to 11 work
wire next_bit = (bit_spacing==4'd10);
always @(posedge clk)
if(state==0)
	bit_spacing <= 4'b0000;
else
if(Baud8Tick)
	bit_spacing <= {bit_spacing + 4'b0001} | {bit_spacing, 3'b000};
always @(posedge clk)
if(Baud8Tick)
case(state)
	4'b0000: if(RxD_bit_inv) state <= 4'b1000;  // start bit found?
	4'b1000: if(next_bit) state <= 4'b1001;  // bit 0
	4'b1001: if(next_bit) state <= 4'b1010;  // bit 1
	4'b1010: if(next_bit) state <= 4'b1011;  // bit 2
	4'b1011: if(next_bit) state <= 4'b1100;  // bit 3
	4'b1100: if(next_bit) state <= 4'b1101;  // bit 4
	4'b1101: if(next_bit) state <= 4'b1110;  // bit 5
	4'b1110: if(next_bit) state <= 4'b1111;  // bit 6
	4'b1111: if(next_bit) state <= 4'b0001;  // bit 7
	4'b0001: if(next_bit) state <= 4'b0000;  // stop bit
	default: state <= 4'b0000;
endcase
reg  RxD_data;
always @(posedge clk)
if(Baud8Tick && next_bit && state) RxD_data <= {~RxD_bit_inv, RxD_data};
reg RxD_data_ready, RxD_data_error;
always @(posedge clk)
begin
	RxD_data_ready <= (Baud8Tick && next_bit && state==4'b0001 && ~RxD_bit_inv);  // ready only if the stop bit is received
	RxD_data_error <= (Baud8Tick && next_bit && state==4'b0001 &&  RxD_bit_inv);  // error if the stop bit is not received
end
reg  gap_count;
always @(posedge clk) if (state!=0) gap_count<=5'h00; else if(Baud8Tick & ~gap_count) gap_count <= gap_count + 5'h01;
assign RxD_idle = gap_count;
reg RxD_endofpacket; always @(posedge clk) RxD_endofpacket <= Baud8Tick & (gap_count==5'h0F);
endmodule

Altera_Forum · ‎12-20-2011

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ive tried using LT spice for simulation purposes since im not that good on using the software i found it hard to come up with the simulation ...i am preparin to do it practically...

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What is harder; learning how to use software (LTSpice), or watching your hardware go up in smoke? The Yahoo LTSpice has lots of helpful users.

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....any advise...

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Learn how to use Modelsim and simulate the Verilog.

Its pointless asking others to read code that you just 'found' on the internet. Show that you have made an effort to try to understand and test the code first, and then people will be more willing to help you when you have problems. Otherwise, your question just comes across as being lazy;

"its too hard, can someone else please do this for me?".

Try and put some effort in first.

Cheers,

Dave