Quadcopter using Cyclone II. How to implement gyro inputs and ESC outputs?

Quick update:

I managed to make a pwm generator and I can now control speed of a brushless motor by flipping switches from the de2 board which sens pwm signals to the ESC.

Now I need to make a pwm decoder since my 2.4ghz receiver outputs pwm signals. The period is 20ms but I will need to program code which detects each duty cycle. Also, I found a gyro that I already own that outputs pwm signals instead of i2c. This will make my hard easier since after I get my pwm decoder to work, I can start writing the algorithm that controls each ESC (which then powers the motors).

Here is my code for the decoder which I haven't been able to test yet.

The pwmsignal has a period of 20ms (50hz) and it will be 1'b1 1-2ms depending if the input is at 100% or at 0%. When input is at 100%, the signal will be 1'b1 for 2ms, when at 50, for 1.5ms and when at 0%, for 1ms. I guess my greatest difficulty is trying to "sync" each 20ms cycle.

Ratio should be a value between 0 and 100 and thats what I'm trying to calculate from the pwmsignal.

Essentially, when pwmsignal is 1 for 2ms, I want ratio to be at 100 and when pwmsignal is 1 for 1ms, I want it to be at 0.

I'd love to hear if anyone has a better way to find the ratio and if my current code would work.

--- Quote Start ---

module gyro(clk, control, pwm,pwmsignal);

input clk;

input pwmsignal;

input [8:0] control;

output pwm;

reg pwm;

reg [31:0] counter = 32'd0;

reg [31:0] signalon = 32'd0; //# of times a sec pwm signal is at 1

reg [31:0] signaloff = 32'd0; //# of time a sec pwm signal is at 0

reg [31:0] ratio = 32'd0;

always @ (posedge clk)

begin

counter <= counter+1;

if (pwmsignal == 1'b1)

begin

signalon <= signalon+1;

end

else

begin

signaloff <= signaloff+1;

end

if ((counter >= 32'd950000)&&(signalon >=500)) //clock speed is 50,000,000hz, signalon >= 500 in case there is error

begin //we want to refresh signal 50 time a sec

counter <= 32'b0;

ratio <= ((signalon-10'd50000)/5000);

//max signalon is 100,000 min is 50,000. This way answer is between 0 and 100

end

else

begin

end

end

endmodule

--- Quote End ---