Do you want to draw bar charts or dials on your LCD screens? Don't write the code, steal mine. This code includes 3 functions, a vertical bar chart, a horizontal bar chart, and a dial. These functions work with Arduino UNO or MEGA, and an Adafruit 3.5 inch 320 x 480 LDC display. This code may work with other displays that use the Adafruit_GFX libraries.
Usage video
Arduino INO code with the graphing functions (from my personal pcloud account). Note: I tried to include the code but it exceeded the 9000 character limit
http://pc.cd/EWirtalK
Link to the Adafruit LCD display and libraries
Any chance for waveshare's lcds? Their configuration is different from adafruit (I'm having 3.5 with no pin details, which one is vcc which one data which one control, etc, nothing mentioned)