Dimming the Raduino Display
by Don Cantrell, ND6T
The Raduino display can be a bit too bright for some folks. The backlight only needs to be bright enough to make the display readable, not to where you can read a book by it. In the sunlight it can be easily read without the internal lighting so that energy is just being wasted.
I brought the brightness of my BITX LCD down by replacing the 110 ohm ballast resistor for that LED with a 470 ohm unit.
On the end of the display where you can see the LED connection you should find a chip labeled R7. It will be on the end next to the USB when the Arduino board is plugged in. That is the device in the photo labeled “111” (that means a “1” followed by a “1” with “1” zero following it: 110 ohms). Replace it with a higher value to dim the light.
Now I can photograph it and read the indications. I saved 18 milliamps of current drain, too.