Guru
Joined: 10/01/2016
Location: United KingdomPosts: 309
| Posted: 02:34pm 23 Jan 2016 |
I have an ILI9341 LCD operating with a Micromite Plus. The 2.8 inch display appears to be identical to that illustrated on Page 17 of the Micromite Manual (5.1) Images load well from the SD card and all is okay except...the LED backlight is not quite as bright as I would like it to be. Referring to the Micromite Manual page 18, I am instructed to connect the LED to 5V via a current limiting resistor and 18R is recommended as a typical value. It then continues "The value of this resistor can be varied to reduce the power consumption or to provide a brighter display." I am now looking for the minimum value that this current-limiting resistor can have; I am having trouble finding any reference to this.
Looking at the schematic for the LCD backpack, I note that there is a variable resistor which would allow, at the end of its travel, a direct connection to 5 volts. Can I just connect the LED pin to 5V or is a current-limiting resistor truly needed and, if so, what should be the minimum value?