A set of gauges to work with Adafruit_GFX
The current implementation can show text, numbers and tape gauges on defined parts of an Adafruit_gfx screen without having to redraw the whole screen. It can even drive multiple screens (provided the underlying hard- and software supports it) and move Gauges from one screen to another. The base Gauge class that all others inherit from, just holds the functions to update the value to be displayed. The value is internally stored as String, but the setValue() function is overloaded for short, int, long, float, duble, char*, const char* and String values thus almost any value can be thrown at it. If a value is not a number, it's up to the visualization class to handle the error
In addition to setValue the only other public functions are setAutoRedraw() and redraw()
- setAutoRedraw(bool val) sets or clears the autoRedraw flag. If the flag is set, a change to value stored by this Gauge will automatically trigger a redraw() for this gauge. This is probably what you want in most cases.
- redraw() manually redraws a gauge. Sometimes, you might want to manually force a redraw or to redraw Gauges on a given fixed interval. This can be done by calling redraw().
For all Gauges that can be shown on an Adafruit_Gfx dislay, the intermediary class displayGauge holds the relevant properties and functions. Note that you won't normally instantiate this class but the more specific classes further down. It provides the following member functions:
- setPosition(uint16_t x, uint16_t y) place the Gauge at a certain screen position. This position is relative to the screen's own orientation
- setSize(uint16_t w, uint16_t h) define the width and heigth of the Gauge. This can be changed at runtime, but be aware that currently, shrinking will not automatically delete the area left open by it
- setDepth(uint8_t z) currently unused There might be stacking in the future, not sure
- setVisible(bool val) currently unused would render the Gauge hidden when set to false (just not redraw at all)
- setDisplay(Adafruit_GFX *display) set the Display for this Gauge to render on
- setFGColor(uint16_t fg), setBGColor(uint16_t bg), setBorderColor(uint16_t bo) set the drawing colors for the respective elements in Adafruit_gfx 16 bit 565 format
- setBorder(uint8_t border) set the width of a border to draw around the Gauge (in fact, it will live inside the rect defined by h and w, the useable gauge area will be reduced by twice the border width) A border of 0 disables drawing the border.
- setGutter(uint8_t gutter_l,uint8_t gutter_r, uint8_t gutter_t, uint8_t gutter_b), setGutter(uint8_t gutter),setMargins(uint8_t gutter_l,uint8_t gutter_r, uint8_t gutter_t, uint8_t gutter_b), setMargins(uint8_t gutter) (setMargins and setGutter are synonymous) set additional free space inside the border. This will be painted in the background color. When using just one argument, the same value is used for all vour edges.
- int getDepth() currently unused get the z-depth of this Gauge
The textGauge adds what is needed to render textual information
- setFont(const GFXfont *font) set the font for the Gauge
- setVAlign(uint8_t align) set vertical alignment of data in the box, align is one of TEXT_TOP, TEXT_MIDDLE, TEXT_BOTTOM
- setHAlign(uint8_t align) set horizontal alignment of data in the box, align is one of TEXT_LEFT, TEXT_CENTER, TEXT_RIGHT
The tapeGauge allows for vertical or horizontal Tapes to be displayed. Those tapes can have up to three color areas defined by two limits - setMinMax(float min, float max) set the minimum and maximum allowable value for this tape - required to correctly scale
- setColors(uint16_t color0,float limit0, uint16_t color1, float limit1, uint16_t color2), setColors(uint16_t color0,float limit0, uint16_t), setColors(uint16_t color0) set the coloring scheme. Five parameters define thre colored segments, three parameters define two segments and a single color means the whole bar has just that color.
- setDirection(uint8_t dir) sets the direction (or orientation) of the tape. dir is one of TAPE_LEFTRIGHT, TAPE_TOPDOWN, TAPE_RIGHTLEFT, TAPE_BOTTOMUP
- setTicks(uint16_t major, uint16_t minor) (not yet implemented) draw minor and major ticks along the cardinal axis
Beware: due to memory requirements, this will currently only work on platforms that have enough free memory available. This library uses Adafruit_Gfx::canvas16 to avoid on screen flicker when refreshing parts of the display. A canvas needs w*h*2 bytes of memory. For a 40x200px canvas, that's almost 16kB! That buffer is only held for a very short time (during the redraw() function call) but if it cannot be fully allocated, the display will probably show gabled information.
dependecies I have tested this library with the following Adafruit display classes:
- Adafruit_ILI9340.h
- Adafruit_ILI9341.h
- Adafruit_SSD1306.h
- Adafruit_ST7735.h
The OLED displays require an additional call to actually update the display (display.display()). Since the Gauges use a reference to the Adafruit_Gfx baseclass and that does not know this function, I had to update this as well. So, to use the gauges, download Adafruit_Gfx from here: https://github.com/pljakobs/Adafruit-GFX-Library