Update README.md

README.md

@@ -1,2 +1,124 @@
-AD9850
-======
+# Arduino serial library for AD9850 #
+F4GOJ Christophe f4goj@free.fr
+
+August 2014
+
+AD9850 datasheet at http://www.analog.com/static/imported-files/data_sheets/AD9850.pdf
+
+Use this library freely.
+
+![ad9850_connections](https://cloud.githubusercontent.com/assets/8761871/4262821/f5b7d230-3bba-11e4-85c7-4f8bd9ee7161.png)
+
+## Installation ##
+To use the **AD9850** library:  
+- Go to https://github.com/F4GOJ/AD9850, click the [Download ZIP](https://github.com/F4GOJ/AD9850/archive/master.zip) button and save the ZIP file to a convenient location on your PC.
+- Uncompress the downloaded file.  This will result in a folder containing all the files for the library, that has a name that includes the branch name, usually **AD9850-master**.
+- Rename the folder to  **AD9850**.
+- Copy the renamed folder to the Arduino sketchbook\libraries folder.
+
+
+## Usage notes ##
+
+The **AD9850** library instantiates a **DDS** object, the user does not need to do this.
+
+```c++
+#include <AD9850.h>    //http://github.com/F4GOJ/AD9850
+
+```
+## Hardware connections : ##
+
+- W_CLK   -> any pin
+- FQ_UD   -> any pin
+- DATA/D7 -> any pin
+- RESET   -> any pin
+
+## Functions : ##
+
+###begin(int w_clk_pin, int fq_ud_pin, int data_pin, int reset_pin)
+#####Description
+Initialize the output pins and master reset the AD9850
+#####Syntax
+`DDS.begin(w_clk, fq_ud, data, reset);`
+#####Parameters
+**w_clk :** Working clock output pin, any pin *(int)*<br>
+**fq_ud :** Frequency update pin, any pin. *(int)*<br>
+**data  :** Serial data output pin, any pin *(int)*<br>
+**reset :** Reset output pin, any pin. *(int)*
+#####Returns
+None.
+#####Example
+```c++
+void setup(){
+ DDS.begin(6, 7, 8, 9);
+}
+```
+###calibrate(double trim_frequency)
+#####Description
+Compensation of crystal oscillator frequency.<br>
+Can be used at any time after initialization.
+#####Syntax
+`DDS.calibrate(trim_freq);`
+#####Parameters
+**trim_freq :** Adjust around 125000000 to match the real crystal oscillator frequency. *(double)*
+#####Returns
+None.
+#####Example
+```c++
+void setup(){
+ DDS.begin(6, 7, 8, 9);
+}
+
+void loop(){
+ DDS.calibrate(124999000);
+}
+```
+###setfreq(double frequency, int phase)
+#####Description
+Sets the output frequency of the AD9850 and the phase of the signal.
+#####Syntax
+`DDS.setfreq(frequency, phase);`
+#####Parameters
+**frequency :** Output frequency in Hz. *(double)*<br>
+**phase :** Sets the phase of the output signal, coded on 5 bits allows 32 phase steps of 11,25° each. *(int)*
+#####Returns
+None.
+#####Example
+```c++
+double frequency = 10000000;
+int phase = 0;
+DDS.setfreq(frequency, phase);
+```
+###down()
+#####Description
+Power down mode reducing the dissipated power from 380mW to 30mW @5V
+#####Syntax
+`DDS.down();`
+#####Parameters
+None.
+#####Returns
+None.
+#####Example
+```c++
+DDS.down();
+```
+###up()
+#####Description
+Wakes-up the AD9850 from power down mode.
+#####Syntax
+`DDS.up();`
+#####Parameters
+None.
+#####Returns
+None.
+#####Example
+```c++
+DDS.down(); // Entering power down mode
+
+// some code doing something
+
+...
+
+DDS.up(); // WAKE-UP !!! :)
+```
+
+