Winstar OLED Brightness Control

nick12ab

Senior Member
#1
Obsolete - Please read Winstar OLED Brightness Control - Version 2.
[HR][/HR]
This blog entry shows you how to add brightness control to a Winstar OLED like that provided with the AXE133Y. You will need to find the resistor VR1. The locations are shown below circled red and are right next to the inductor in both cases:
• Normal size 16x2 OLED module (mrburnette's picture)

• Large size 16x2 OLED module (purchased separately from Rapid)

Edit: Here's a better close-up of the module with the variable resistor pads indicated by the red down-pointing arrow:


You'll find that there's pads for a variable resistor but there's only a fixed resistor. Desolder and remove this resistor, noting its value (in the case of the large module, it was 4.3K).

Now connect a (digital) potentiometer in its place (100-470K). Alternatively, you can cut the tracks going to pins 15 and 16 and wire the VR1 pads to pins 15 and 16 to make it easier to control the brightness on your project board. Either way, you should connect the resistor you removed in series with the variable resistor to prevent the resistance from getting too low as that may damage the OLED.

Check the connection as an accidental short may be fatal. To test the OLED, set the potentiometer to 0 ohms with the original resistor in series then connect and power on the OLED to test it.

NORMAL ....... DIM


The result is that you can dim the OLED between full brightness and approximately a third of that brightness. Unlike quickly turning on and off the panel, this method does not cause any extra flicker and oscillator drift will not cause the possible serious problem with the on/off method.
 
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