DDS AD9914 / AD9915 Arduino Shield

DDS (Direct Digital Synthesis) Analog Devices AD9914/AD9915 Arduino Shield by GRA & AFCH

DDS (Direct Digital Synthesis) Analog Devices AD9915 Arduino Shield by GRA & AFCH
The difference between the two RF Shield Units is only in the maximum clocking frequency of the DDS core
In DDS AD9915 Shield Unit it is nominally 2.5 GHz and it can be overclocked to 3 GHz
In DDS AD9914 Shield Unit it is nominally higher than 3.5 GHz and can be overclocked to 4 GHz
The firmware is the same for AD9914 and AD9915 except for the inscription on the OLED screen, you need to change line 14 in the DisplayMenu.ino file to display.printin(F("DDS AD9914"));

Web-site: https://gra-afch.com Direct link to category: https://gra-afch.com/product-category/rf-units/

GA_Flasher can be used to upload compiled firmware from "Firmware Compiled (.HEX File)" folder: https://github.com/afch/GA_Flasher

"Firmware Compiled (.HEX File)" - folder contains pre-Compiled firmware (.HEX File), that can be uploaded via "AvrDude", GA_Flasher or any other software for flashing Atmega 2560

"Firmware Source (.INO File)" - folder contains source of firmware that can be compiled (modified if necessary) and uploaded via Arduino IDE: https://www.arduino.cc/en/Main/Software

"Libraries" - contains libraries that are only needed for compilation: place them to "C:\Users[USER]\Documents\Arduino\libraries", where [USER] - your windows username.

This AD9959 Shield can be easily connected to Arduino Mega without additional wires and converters. All functions of the DDS AD9914/AD9915 are brought to the contacts of the Arduino Mega thanks to this you can fully reveal all the capabilities of the DDS AD9914/AD9915.

Key Benefits:

• Low harmonics no more than -60dB. An output RF transformer is used for the correct operation of the current mirror.
• balancing transformer for TCXO and REF CLK IN options
• Small spur
• 4 layer board. Signal lines TOP and Bottom, inner layers Ground and Power.
• Low Noise LDO Stabilizers
• Separate power supply for all analog and digital lines (1.8 and 3.3V), 5pcs IC voltage stabilizers are used. Additionally, there is an RF Ferrite bead interchange.
• High-speed decoupling Level converter and TTL 5V matching
• one of these types of clock source can be used/installed:

1. TCXO - 5 - 50 Mhz 1ppm external oscillator PLLz,
2. REF CLK IN - external generator 500 MHz to 4000 MHz

• Easy to connect OLED display.
• Convenient and fast control with an encoder
• The synthesizer is capable to generate sine wave.
• The software allows you to select and configure the frequency of the clock generator through the user menu (without the need to recompile the program).
• Any settings can be stored in non-volatile EEPROM memory (located at Arduino Mega).
• Basic settings are applied and saved automatically.
• This shield support overclocking the AD9914/AD9915 core up to 4000 MHz.
• DDS AD9914/AD9915 Shield has ability to generate a signal up to 1999 MHz.

Switching a clock source is made by next components:

|-------------------------------|-----------------------------------|-----------------|
|      Clock source             |            Capacitors             |    Resistors    |
|   (only one at a time)        | C20  |  C22  |  C18,C19 | C14,C17 |  XTAL | REF_CLK |
|-------------------------------------------------------------------------------------|
| TCXO - Oscillator 1ppm (Z2)   |  V   |   X   |    X     |    V    |   X   |    V    |
| REF CLK - External Generator  |  X   |   X   |    X     |    V    |   X   |    V    |
|-------------------------------------------------------------------------------------|

Where V means that the component must be installed (soldered), and X - means that the component must be removed

List of Serial Port Commands:

Starting with version 0.82, the ability to control via the serial port has been added.

F - Set Frequency in Hz (100000 - CoreFrequency/2)
P - Set Output Power in dBm (-68 - 0)
M - Get Model
V - Get Firmware Version
E - Enable Output
D - Disable Output
h - Help
; - Commands Separator

Example:
F100000;P-2
Set Frequency to 100 kHz, and Output Power to -2 dBm.
Any number of commands in any order is allowed.

Serial Port Settings:

Speed - 115200 Bouds
Data Bits - 8
Stop Bits - 1
Parity - No
DTR - OFF

Windows:

An example of setting up a serial port in the Windows console:

  mode COM3 baud=115200 DTR=OFF Data=8
  

Usage example:

  echo F100000000 > COM3
  

Ubuntu 22.04:

An example of setting up a serial port in the Ubuntu:

  sudo usermod -aG dialout $USER_NAME$
  sudo chmod a+rw /dev/ttyUSB0
  sudo stty -F /dev/ttyUSB0 115200 cs8 ixoff -hupcl -echo
  

Usage example:

  echo "F100000000" > /dev/ttyUSB0