rotMatrix is an Arduino sketch for driving a 16x16 WS2812b matrix to display lowtech images. It integrates an optional rotary encoder as a means to control the display. It offers several alternative sources for image data and ways to specify which of them to show.
It currently supports a limited number of images stored in dedicated variables in matrixImg.h Those 16 pics are sometimes referenced as 'internal'
It supports image data on the mcu's build-in flash, nominally 3 MB though but with fixed block size and small files the number is the limiting factor (<800). This is sometimes freferenced as 'external'
Finally the sketch supports receiving image data on the fly as a list of rgb values.
In all cases the image data are 256 hex rgb values which describe the 16x16 matrix in a zig-zag way (16 values left-to-right, change of row, 16 values right to left, change of row, repeat)
Regardles where stored the image data need to be shuffled accordingly to render propperly. A bash script which does take care of this requirement and batch converts a folder of png images can be found at https://github.com/planetar/matrixPics
The sketch supports 2 different ways to select images and adjust parameters:
- mqtt messages (sort of the native language) and
- manual input with a rotary endoder
The rotary encoder's switch shifts three functions, initially the encoder regulates the brightness, the next level circles through the 'internal' pics and the last level circles through the 'external' pics.
This sketch was developped and tested with arduino ESP8266 core 2.4.2
- 2.5.0 has occasional but rather frequent crashes in SPIFFS
- core versions above 2.5.0 have breaking changes in the way interrupts are handled and may not work.
The Sketch is prepared to keep some config separate for a range of devices which run individual compiles of the sketch, define it below. In other words you can have a number of devices running in the same network and they each have a separate id and can be addressed independently via mqtt.
The sketch has an infrastructure of connection to wifi with shared secrets, mqtt with shared secrets and Arduino OTA with shared secret.
bome sort of optical feedback of the current level of the rotary encoder would really help.
- "scanWifi":"ON" / "OFF" if ON wifi performs a scan of available wifi nets and reports them, SSID und RSSI on mqtt wifiscan/id
- "state":"ON" / "OFF" on/off-switch, however, setting brightness to 0 is less destructive
- "hueRange":int rangeWave parameter
- "quart": int rangeWave parameter
- "animFactor" multiplicator for stepTime
- "stepTime" ms of each animStep
- "bright" brightness from 0 to 255, if less than 6 color depth is very reduced. Defines how much power is needed
- "brightness" synonym. so it's advisable to not go up to high when powered from just an usb-wallwart
- "colorHsv" baseColor as HSV hue saturation Value range 0-255.
- "effect" one of the following effects:
-
the 16 'internal' images can each be selected by name of the variable:
- om
- danke
- herz
- kreis
- kuss
- schmetterling
- delphin
- maskulin
- feminin
- regenbogen
- tatzen
- cool
- apfel
- banane
- erdbeer
- melone
-
shiftBand rangeWave sineHue 3 color animations designed for led strips, on the matrix they appear as color stripes
-
solid solid shows the baseColor as a solid block, change it with colorHsv
-
kelvin shows a color given in Kelvin as a solid block. Wide range of yellow, orange
-
adhoc (data) allows to define an image on the fly, supply the rgb values as a list in data
-
showByIndex selects an image by it's position in the index table for the 'external' images
-
showByName selects an image by it's name from the 'external' images
-
cycleInt cycles a range from the 'internal' images, starting with von, ending at bis
-
cycleExt cycles a range from the 'external' images, starting with von, ending at bis
-
cycleByName cycles through a list of images given as parameter.
mosquitto_pub -h mqtt-host -u user -P password -t led/mm/set -m '{"state":"ON","effect":"om","bright":8}'
mosquitto_pub -h mqtt-host -u user -P password -t led/mm/set -m '{"cycleInt":{"von":2,"bis":"3"},"stepTime":8000,"bright":12}'
mosquitto_pub -h mqtt-host -u user -P password -t led/km/set -m '{"cycleExt":{"von":219,"bis":"231"},"stepTime":600}'
mosquitto_pub -h mqtt-host -u user -P password -t led/mm/set -m '{"showByName":"1f958"}'
mosquitto_pub -h mqtt-host -u user -P password -t led/mm/set -m '{"cycleByName":"1f964,1f958,1f957,1f951,1f95d,1f95e","stepTime":2000}'
mosquitto_pub -h mqtt-host -u user -P password -t led/mk/set -m '{"state":"ON","bright":6,"effect":"adhoc","data":"0x040404, 0x040302, 0x02080e, 0x011224, 0x021529, 0x021529, 0x021528, 0x021528, 0x021528, 0x021528, 0x021529, 0x021529, 0x011224, 0x02080e, 0x040302, 0x040404,0x040302, 0x031425, 0x195389, 0x4a86bd, 0x5891c4, 0x5891c4, 0x5891c4, 0x5891c4, 0x5891c4, 0x5891c4, 0x5891c4, 0x5891c4, 0x4a86bd, 0x195389, 0x031425, 0x040302,0x020910, 0x145491, 0x6aade7, 0x76b5ed, 0x70b2ed, 0x70b3ed, 0x6fb3ed, 0x6fb3ed, 0x70b3ed, 0x70b2ed, 0x70b2ed, 0x71b3ed, 0x76b5ed, 0x6aade7, 0x145491, 0x020910,0x02152b, 0x2a7bc6, 0x5ca9eb, 0x53a3e9, 0x4d9ee7, 0x50a0e8, 0x54a4ea, 0x549fe7, 0x5d9ae1, 0x5e9ae1, 0x589be4, 0x53a3e9, 0x54a4e9, 0x5ca9eb, 0x2b7bc6, 0x02152b,0x021832, 0x227acc, 0x499fea, 0x489ee9, 0x469ce8, 0x85b0e7, 0xa8bde6, 0x9ab7e7, 0x55a0e8, 0x449be8, 0x4d90e4, 0x5e93e0, 0x499be7, 0x499fea, 0x227acc, 0x021832,0x031832, 0x1b75cb, 0x3b97e9, 0x4ea0e9, 0xc2d5f2, 0x7cb1ec, 0x3d97e8, 0x3e95e8, 0x99baeb, 0xc3cfec, 0x8eb6ea, 0x3a95e7, 0x3c96e8, 0x3c97e9, 0x1b75cb, 0x031832,0x031732, 0x0f6cca, 0x2c8de7, 0x2e8ee6, 0x2886e4, 0x73adeb, 0xcad9f1, 0x76abe6, 0x2784e3, 0x2c8de6, 0x79b4ed, 0xafd1f2, 0x3a94e7, 0x2b8ce7, 0x0f6cca, 0x031732,0x041731, 0x0462c8, 0x0e78e4, 0x167ae3, 0x538ae1, 0x3f80de, 0x1870de, 0x6d93df, 0xb3c3e5, 0x99b6e8, 0x5786e0, 0x4b87e2, 0x157ae3, 0x0e78e4, 0x0462c8, 0x041731,0x041631, 0x045dc7, 0x046de2, 0x0167e0, 0x7facec, 0xccd3ee, 0x7f9ee5, 0xdde6f6, 0xcad5f0, 0x8fa0da, 0xb0bde5, 0x669de8, 0x0469e1, 0x046de2, 0x045dc7, 0x041631,0x041531, 0x0459c7, 0x0469e2, 0x0368e1, 0x0869e1, 0x5c9be9, 0xb2ccf0, 0x4f8ce7, 0x6b93e4, 0xb1beea, 0xfffcf9, 0x7caaec, 0x0064e0, 0x0469e2, 0x0459c7, 0x041531,0x041431, 0x0455c6, 0x0464e1, 0x0060df, 0x7ca8eb, 0xe9edf5, 0xd9e1f2, 0x7392e2, 0x085cde, 0x0f68e1, 0x0462e0, 0x0362e0, 0x0463e0, 0x0464e1, 0x0455c6, 0x041431,0x041331, 0x0451c6, 0x045ee0, 0x045edf, 0x045edf, 0x035edf, 0x025ddf, 0x1360de, 0x88a2de, 0x9cb0dd, 0xc1cbe9, 0x7da6eb, 0x005ade, 0x045ee0, 0x0451c6, 0x041331,0x04112c, 0x044bc2, 0x045adf, 0x0257de, 0x4281e5, 0x86adec, 0x85aceb, 0x75a1ea, 0x1361e0, 0x0358de, 0x0459de, 0x0459de, 0x0459de, 0x045adf, 0x044bc2, 0x04112c,0x040813, 0x05379c, 0x0655e0, 0x0655df, 0x0655de, 0x0655de, 0x0655de, 0x0655de, 0x0454de, 0x0453de, 0x0453de, 0x0554de, 0x0755df, 0x0655e0, 0x05379c, 0x040813,0x040302, 0x041131, 0x0636a1, 0x0846ca, 0x0848cd, 0x0848cd, 0x0848cd, 0x0848cd, 0x0848cd, 0x0848cd, 0x0848cd, 0x0848cd, 0x0846ca, 0x0636a1, 0x041131, 0x040302,0x040404, 0x040302, 0x040916, 0x041235, 0x05143c, 0x05133c, 0x05133c, 0x05133c, 0x05133c, 0x05133c, 0x05133c, 0x05143c, 0x041235, 0x040916, 0x040302, 0x040404,"}'
A diffusor, or scrim, softens the light and spreads it over a wider area. In the matrix there is a very bright LED and then 8mm darkness in each direction and then the next led. That makes recognizing subtle differences in brightness and colour very difficult and our brains fail to recognize an image unless it is 'flat' with few colours and no dithering.
With a diffusor the light of each LED ideally covers the entire 10x10mm plain around it. And suddenly the error correction in our visual cortex works wonders and allows us to recognize fine structures from dithered colours. Looking directly at the matrix there is only pixel salad, with the diffusor in between and some distance I see the emoji-picture. (for that is what I was trying to achieve, a display for emoji icons)
You can find such a thing at https://www.thingiverse.com/thing:4159218
An enclosure which holds the matrix, a diffusor, mount points for the rotary encoder and the mcu is in the making. There is a 3d model for an enclosure that lacks the diffusor (so you would have to glue that on top of it). Open an issue if you want that.