WS2812B 241-LED 9-ring disc: specs and pinout
A round board of 241 WS2812B 5050 addressable RGB LEDs arranged in 9 concentric rings. Each LED has a built-in driver and is controlled over one data wire. The Worldsemi chip sheets describe the LEDs; the ring board itself is not documented.
Specs
| Spec | Value | Source |
|---|---|---|
| LED supply (VDD), operating | 4.5 V to 5.5 V | source Electrical Characteristics (page 2) |
| LED supply (VDD), absolute maximum | +3.5 V to +5.3 V as printed on the older sheet; +3.3 V to +5.3 V on the V7 sheet | source Absolute Maximum Ratings (page 2); V7 sheet page 3 |
| Data input high level | At least 0.7 x VDD on the WS2812B sheet (3.5 V at 5 V); at least 0.55 x VDD on the newer V7 sheet (2.75 V at 5 V) | source Electrical Characteristics (page 2); V7 sheet page 3 |
| Data protocol | Single-wire, 800 kbps; 24 bits per LED in the order G, R, B, high bit first; 256 levels per colour | source Data transfer time and Composition of 24bit data (pages 3-4) |
| Bit timing and reset | Older sheet (WS2812B, via a hosted copy): T0H 0.4 us, T1H 0.8 us, T0L 0.85 us, T1L 0.45 us, each +/-150 ns; reset is data low for more than 50 us. V7 sheet V1.3 (Worldsemi), p.4: T0H 220-380 ns, T1H 580 ns to 1 us, T0L 580 ns to 1 us, T1L 580 ns to 1 us; reset (RES) more than 280 us. The chip revision on this ring is unknown, so hold data low for at least 280 us. | source Older sheet: Data transfer time (p.3); V7 sheet: Data Transfer Time (p.4) |
| Current per LED | 16 mA per colour is the test condition for the brightness figures on the V7 sheet, which is 48 mA per LED with red, green and blue all on. The older WS2812B sheet gives no per-LED current. | source LED Characteristics, test condition 16 mA (page 4) |
| Worst-case ring current | 241 LEDs x 48 mA = about 11.6 A at full white, from the 16 mA test condition. This is a planning figure, not a maker rating | source Derived from the 16 mA test condition on page 4 |
| Quiescent current | 1 uA maximum per LED with no signal and RGB off (V7 sheet only) | source Electrical Characteristics (page 3) |
| Operating temperature | -25 to +80 C (older sheet); -40 to +85 C working temperature (V7 sheet) | source Absolute Maximum Ratings (page 2); V7 sheet page 3 |
Power
| Value | Source | |
|---|---|---|
| Supply | 5 V (4.5 V to 5.5 V) | source LED Characteristics (page 4) |
| Current | No rated figure. Planning figure from the 16 mA per colour test condition: 48 mA per LED at full white, about 11.6 A for 241 LEDs | source LED Characteristics (page 4) |
Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently.
Pin names are the WS2812B chip pads. The ring board's connector, its power and data pads, its ring layout (LEDs per ring and order) and which WS2812B revision is fitted are not covered by an official document. Check the board marking for the input end before powering it.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| VDD | Power supply (chip pad 1) | 4.5 V to 5.5 V | Board pad labels not documented | source PIN function (page 2) |
| DOUT | Control data signal output (chip pad 2) | Chains to the next LED; board pad labels not documented | source PIN function (page 2) | |
| VSS | Ground (chip pad 3) | Board pad labels not documented | source PIN function (page 2) | |
| DIN | Control data signal input (chip pad 4) | 0.7 x VDD minimum for a high | Board pad labels not documented | source PIN function (page 2) |
Build with it
Project ideas for the WS2812B 241-LED 9-ring disc. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Knob-dimmed pattern lamp: The Uno gives 5 V data that meets the 0.7 x VDD input level. Feed the ring straight from the 5 V 5 A supply (not through the Uno), join the grounds, and cap brightness in firmware: at the 16 mA per colour test condition, 25 percent of 11.6 A is about 2.9 A. The potentiometer on an analog pin only picks patterns or a dimmer level below that cap. Measure the ring's draw with a meter in series, and feed power at more than one point if the board has more than one pair of pads. Join the supply to the ring's power pads with a barrel-jack-to-terminal adapter you already own (not sold here), + and - as the supply's label shows; do not wire a bare mains supply.
- Ring clock: The ring's LED layout is not documented, so first run a test sketch to find which LEDs form each ring and where it starts. Light only a few LEDs at a time, keep the cap at 25 percent, and power the ring from the supply rather than the Nano. Measure the ring's draw with a meter in series, and feed power at more than one point if the board has more than one pair of pads. Join the supply to the ring's power pads with a barrel-jack-to-terminal adapter you already own (not sold here), + and - as the supply's label shows; do not wire a bare mains supply.
- Sound-reactive ring: The amplifier's analog output goes to an Uno analog input and lights more LEDs as the level rises. Sound peaks switch many LEDs at once, so keep the firmware brightness cap and a supply that can carry the cap current. Measure the ring's draw with a meter in series, and feed power at more than one point if the board has more than one pair of pads. Join the supply to the ring's power pads with a barrel-jack-to-terminal adapter you already own (not sold here), + and - as the supply's label shows; do not wire a bare mains supply.
Common mistakes
- Powering 241 LEDs from a USB port or a small adapter: at the 16 mA per colour test condition, full white is 241 x 48 mA, about 11.6 A, so use a 5 V supply sized for the brightness you set (for example 5 V 5 A with firmware brightness capped near 25 percent, about 2.9 A; at 20 mA per colour the 25 percent cap is about 3.6 A, still under 5 A) and join the grounds. The cap lives in firmware: set it before the first show() call and consider an inline fuse rated above the capped current, in an inline fuse holder you already own (source: link, LED Characteristics p.4)
- Driving the data line from a 3.3 V board while the LEDs run from 5 V: the older sheet needs at least 0.7 x VDD (3.5 V) to read a high, so use a 5 V board or a fast level shifter (source: link, Electrical Characteristics p.2)
- Over-volting or sending colours in the wrong order: absolute maximum VDD is 5.3 V, and data order is G, R, B, not R, G, B (source: link, Absolute Maximum Ratings p.2 and Composition of 24bit data p.4)
Not covered by the official source
- The product name says 241 LEDs in 9 rings; the ring layout, power and data pads, and the WS2812B revision fitted are not covered by an official document.
- The older WS2812B sheet gives no per-LED current. The 16 mA per colour figure is a test condition on the newer V7 sheet, so the current figures here are planning values, not ratings. Measure the ring's draw with a meter in series before choosing a larger supply.
- The two Worldsemi sheets differ in absolute-maximum VDD (3.5 V to 5.3 V against 3.3 V to 5.3 V), in data timing and in reset time (older sheet more than 50 us, V7 sheet more than 280 us); this page lists both and advises at least 280 us.