{"openapi":"3.1.0","info":{"title":"555 Timer Calculator API","version":"1.0.0","description":"555-timer (NE555) astable and monostable design as an API, computed locally and deterministically. The astable endpoint designs the classic oscillator: from the two timing resistors R1 and R2 and the capacitor it returns the output frequency f = 1/(ln2·(R1+2R2)·C), the high and low times (T_high = ln2·(R1+R2)·C, T_low = ln2·R2·C), the period and the duty cycle (R1+R2)/(R1+2R2), or solves the capacitor for a target frequency. The monostable endpoint designs the one-shot timer, T = 1.1·R·C — the pulse width of a single output pulse — and solves for whichever of the resistance, capacitance or pulse width you leave out. The design endpoint works backwards: from a target frequency, a chosen capacitor and a duty cycle it computes the resistor values R1 and R2 you need (a standard 555 needs a duty above 50 %). Capacitors may be entered in farads, microfarads, nanofarads or picofarads. Everything is computed locally and deterministically, so it is instant and private. Ideal for electronics-hobbyist and maker tools, oscillator, blinker, PWM and timing-circuit design, and electronics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is 555-timer design; for Ohm's law, reactance and RC time constants use an Ohm's-law API.","contact":{"name":"PremiumApi","url":"https://www.oanor.com/by/premiumapi"}},"servers":[{"url":"https://api.oanor.com/timer555-api","description":"oanor gateway"}],"tags":[{"name":"555 Timer"},{"name":"Meta"}],"components":{"securitySchemes":{"oanorKey":{"type":"apiKey","in":"header","name":"x-oanor-key","description":"Get your key at https://www.oanor.com/developer/keys"}}},"security":[{"oanorKey":[]}],"paths":{"/v1/astable":{"get":{"operationId":"get_v1_astable","tags":["555 Timer"],"summary":"Astable oscillator","description":"","parameters":[{"name":"r1","in":"query","required":false,"description":"Resistor R1 (Ω)","schema":{"type":"string"},"example":"1000"},{"name":"r2","in":"query","required":false,"description":"Resistor R2 (Ω)","schema":{"type":"string"},"example":"10000"},{"name":"capacitance_uf","in":"query","required":false,"description":"Capacitor (µF)","schema":{"type":"string"},"example":"10"},{"name":"capacitance_nf","in":"query","required":false,"description":"Or capacitor (nF)","schema":{"type":"string"}},{"name":"frequency","in":"query","required":false,"description":"Or target frequency (Hz) to solve C","schema":{"type":"string"}}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"r1_ohm":1000,"r2_ohm":10000,"formula":"f = 1/(ln2·(R1+2R2)·C); duty = (R1+R2)/(R1+2R2).","period_s":0.1455609079,"duty_cycle":0.52380952,"time_low_s":0.0693147181,"time_high_s":0.0762461899,"frequency_hz":6.869976,"capacitance_f":1.0e-5,"duty_cycle_percent":52.380952},"meta":{"timestamp":"2026-06-04T10:18:37.996Z","request_id":"96985952-37ff-4f62-a8a9-366aa22b11d0"},"status":"ok","message":"Astable oscillator","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/design":{"get":{"operationId":"get_v1_design","tags":["555 Timer"],"summary":"Astable resistor design","description":"","parameters":[{"name":"frequency","in":"query","required":true,"description":"Target frequency (Hz)","schema":{"type":"string"},"example":"1000"},{"name":"capacitance_nf","in":"query","required":false,"description":"Chosen capacitor (nF)","schema":{"type":"string"},"example":"10"},{"name":"capacitance_uf","in":"query","required":false,"description":"Or capacitor (µF)","schema":{"type":"string"}},{"name":"duty_cycle","in":"query","required":false,"description":"Duty cycle 0.5–1 (default 0.6)","schema":{"type":"string"},"example":"0.6"}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"r1_ohm":28853.9008,"r2_ohm":57707.8016,"formula":"R1+2R2 = 1/(f·ln2·C); R1 = (2d−1)·S; R2 = (1−d)·S.","period_s":0.001,"duty_cycle":0.6,"capacitance_f":1.0e-8,"target_frequency_hz":1000},"meta":{"timestamp":"2026-06-04T10:18:38.099Z","request_id":"fc3d8467-83db-42f7-8ab2-ee6799b8f7f8"},"status":"ok","message":"Astable resistor design","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/monostable":{"get":{"operationId":"get_v1_monostable","tags":["555 Timer"],"summary":"Monostable one-shot","description":"","parameters":[{"name":"resistance","in":"query","required":false,"description":"Resistor R (Ω)","schema":{"type":"string"},"example":"10000"},{"name":"capacitance_uf","in":"query","required":false,"description":"Capacitor (µF)","schema":{"type":"string"},"example":"100"},{"name":"pulse_width","in":"query","required":false,"description":"Or pulse width (s) to solve R/C","schema":{"type":"string"}}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"formula":"T = 1.1·R·C (one-shot pulse width).","capacitance_f":0.0001,"pulse_width_s":1.1,"capacitance_uf":100,"pulse_width_ms":1100,"resistance_ohm":10000},"meta":{"timestamp":"2026-06-04T10:18:38.201Z","request_id":"b5c145b6-07c0-4db6-b0db-807ea5030789"},"status":"ok","message":"Monostable one-shot","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}},"/v1/meta":{"get":{"operationId":"get_v1_meta","tags":["Meta"],"summary":"Spec","description":"","parameters":[],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"api":"timer555","note":"555-timer astable & monostable design — computed locally and deterministically, no key, no third-party service.","endpoints":["/v1/astable","/v1/monostable","/v1/design","/v1/meta"]},"meta":{"timestamp":"2026-06-04T10:18:38.308Z","request_id":"ad74d552-9500-4bae-b0da-4e271360acb1"},"status":"ok","message":"Meta","success":true}}}},"401":{"description":"Missing or invalid x-oanor-key header"},"402":{"description":"Active subscription required"},"429":{"description":"Rate-limit or monthly quota reached"},"502":{"description":"Upstream did not respond"}}}}},"x-oanor-pricing":[{"slug":"free","name":"Free","price_cents_month":0,"monthly_call_quota":2000,"rps_limit":2,"hard_limit":true},{"slug":"starter","name":"Starter","price_cents_month":800,"monthly_call_quota":25000,"rps_limit":5,"hard_limit":true},{"slug":"pro","name":"Pro","price_cents_month":2200,"monthly_call_quota":150000,"rps_limit":15,"hard_limit":true},{"slug":"mega","name":"Mega","price_cents_month":6900,"monthly_call_quota":768000,"rps_limit":40,"hard_limit":true}],"x-oanor-marketplace-url":"https://www.oanor.com/api/timer555-api"}