# LED rings - 270 degrees or 360? **URL:** \ **Category:** MIDIbox HUIs\ **Created:** [December 7, 2017, 7:59pm UTC](https://forum.midibox.org/t/led-rings-270-degrees-or-360/20137 "2017-12-07T19:59:07Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Metrophage](https://forum.midibox.org/letter_avatar_proxy/v4/letter/m/a88e57/32.png) [@Metrophage](https://forum.midibox.org/u/Metrophage)\ **Post date:** [December 7, 2017, 7:59pm UTC](https://forum.midibox.org/t/led-rings-270-degrees-or-360/20137/1 "2017-12-07T19:59:07Z")
Hello all! I have been away for a while, and looking forward to revisiting some of my projects this winter.   I had avoided making an MB64 type controller because I wanted to use encoders but felt intimidated by discrete wiring of LED rings. Now I am more confident, and might just make a PCB for this.    What I am wondering is - why do all of the examples I see have the LEDs of the ring spaced with a similar approximate  270 degree rotation, like with an analog pot? My Bourns encoders (I bought for a SEQ3 ages ago) have continuous rotation, so it seemed obvious to me to have continuous indicators also, an equally-spaced circle. So I am wondering are there any aesthetic or functional reasons for the 270 degree arc? If I make them 360 instead would I need to change anything in the code? Thanks ---
**Author:** ![Antichambre](https://forum.midibox.org/user_avatar/forum.midibox.org/antichambre/32/201_2.png) [@Antichambre](https://forum.midibox.org/u/Antichambre)\ **Post date:** [December 7, 2017, 8:45pm UTC](https://forum.midibox.org/t/led-rings-270-degrees-or-360/20137/2 "2017-12-07T20:45:10Z")
Hello, For code change it depends, if you need to draw a 270° scale within a 360° led ring, the answer is yes. If not, you don’t need. It’s better to use a multiple of 8 for the number of leds that form your ring. My opinion is that an Open Ring is better for layout routing first and a potentiometer travel is a symbol for me then maybe by convention… Using a ring for a potentiometer In parallax mode(or not) is very interesting for feeling and playability. 300° pots are also common, with a 300° led ring you can draw a 270° travel too. This angle lets the possibility to use most common pots and encoders. I thought a lot about this subject during the OLRE16 design… One more thing… I choose to remove one led from the ring. By this way there’s an odd number of leds, by symmetry the middle led is automatically placed at 0 o’clock, better for bipolar travel ;). The last one is used as an index(e.g. step position, on, mute, solo), and placed at 6 o’clock. Best Bruno ---
**Author:** ![Hawkeye](https://forum.midibox.org/user_avatar/forum.midibox.org/hawkeye/32/223_2.png) [@Hawkeye](https://forum.midibox.org/u/Hawkeye)\ **Post date:** [December 8, 2017, 10:41am UTC](https://forum.midibox.org/t/led-rings-270-degrees-or-360/20137/3 "2017-12-08T10:41:12Z")
And one little user-interface aspect, having a defined “start” and “end” can make things visually more intuitive, e.g. when you have a huge controller board with many LED-rings, it is easier to see, if a parameter is “close to the beginning” or the “end” of a range, if you have a “ring”, that is not a full 360°. This comment does not apply, if you have a “progress-bar” ring, that “turns on” more LEDs (not just one) as the parameter value is increased. ---
**Author:** ![Metrophage](https://forum.midibox.org/letter_avatar_proxy/v4/letter/m/a88e57/32.png) [@Metrophage](https://forum.midibox.org/u/Metrophage)\ **Post date:** [December 11, 2017, 4:22pm UTC](https://forum.midibox.org/t/led-rings-270-degrees-or-360/20137/4 "2017-12-11T16:22:41Z")
Thanks for the input! What I suspect will happen is that I will do all the hard, expensive work of drilling out an enclosure and wiring LEDs, only to want to re-do them once I am using the box. So I suppose I should try breadboarding something first to understand something of how it works.   Antichambre: That was another reason I was thinking about 360 degrees - it is easy to start from “compass point” orientation while keeping 16 LEDs.   Hawkeye: Is that how the MB code defaults to working, within a range? If so, does the indicator just stop at the end if the encoder rotates further? I guess that this makes more visual sense. If I advanced one LED per value, there would be no visual indication of what cycle I was on. Unless they changed color after 16 or something.   Thanks for the help!