#embedded

RC servo and PWM maths as an API, computed locally and deterministically — the pulse-width, angle and duty-cycle numbers a robotics, RC or embedded developer drives a servo with. The angle endpoint turns a pulse width into the servo angle: a hobby servo reads the width of the pulse (not a duty cycle), so the standard 1000–2000 µs maps linearly across the travel with 1500 µs at centre — angle = (pulse − min) ÷ the min-to-max span × the travel — and it flags when a pulse asks for more than the configured range so you do not drive the servo into its mechanical stops. The pulse endpoint runs it the other way, giving the pulse width a microcontroller should write for a target angle (90° is 1500 µs on a 1000–2000 µs / 180° servo), exactly what an Arduino-style servo library computes under the hood. The duty endpoint converts a pulse and a refresh frequency into the PWM period and duty cycle: a 50 Hz servo frame is 20 ms, so a 1500 µs pulse is just 7.5 % duty — the value a timer peripheral needs — and faster frames for digital servos or multirotor ESCs (e.g. 333 Hz) change it. Everything is computed locally and deterministically, so it is instant and private. Ideal for robotics and RC firmware, microcontroller and embedded tools, drone and animatronics projects, and maker calculators. Pure local computation — no key, no third-party service, instant. 3 compute endpoints. For stepper steps-per-mm use a stepper-motor API.

api.oanor.com/servo-api

Resistive voltage-divider circuit design as an API, computed locally and deterministically. The divide endpoint takes an input voltage and two resistors and returns the output voltage Vout = Vin·R2/(R1+R2), the current I = Vin/(R1+R2) that flows through the chain, and the power dissipated in each resistor and in total — a 12 V source with R1 = 1 kΩ and R2 = 2 kΩ gives 8 V at 4 mA. The loaded endpoint adds a load resistor across R2, computes the parallel combination R2′ = R2·RL/(R2+RL) and the loaded output Vout = Vin·R2′/(R1+R2′), and reports the droop in volts and percent against the unloaded value, the classic mistake when a divider feeds a real load. The resistor endpoint sizes the missing resistor for a target output — R2 = R1·Vout/(Vin−Vout) or R1 = R2·(Vin−Vout)/Vout — so you can pick parts for a reference or sensor-bias point. All quantities are volts, ohms, amps and watts. Everything is computed locally and deterministically, so it is instant and private. Ideal for electronics, embedded, hardware, sensor-interfacing and EE-education app developers, reference-voltage and bias-network tools, and maker software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is the resistive divider; for a single Ohm’s-law relationship use an Ohm’s-law API and for RC/RL filters an RC-filter API.

api.oanor.com/voltagedivider-api