To just install some boards in a box and other than an On/Off switch have no user interface? No we did not like that at all. Some color got to be part of the equation. After all the unit must look good when it is presented to the local ham group.
Therefore we decided to add a TFT color display to connect to the DDS Synthesizer.
The DDS board includes a connector strip that offers the necessary signals. Therefore all thats necessary is to connect a cable between this connector strip and the display. Nothing more to do. There is no interface board needed, just the fairly cheap display.
We picked the ITDB02-1.8SP TFT LCD as the display. It is available from several sources for under $20. It contains a SPI bus allowing a connection with just a few wires.
|Pin description on display||Pin description on DDS connector strip|
The display contains a LM117 voltage regulator which normally provides the 3.3V.
However, as we supply the display directly with 3.3V from the board we do not need this voltage regulator. Therefore we remove it. This is easy to do. Its the only 3 pin chip on the display board. Just heat up all three pins until the chip falls off.
Now connect the display with a cable to the DDS board and check with a meter to ensure that the Ground and 3.3V connections are correct. Then turn it on and the operating state will instantly be displayed.