evalship-hq / ponytail

Output

Need to confirm: MCP3008 has no built-in library in stdlib, so you need a dependency. The standard choice is `adafruit-circuitpython-mcp3xxx` (pulls in busio/digitalio). I'll use it. You also need the thermistor's specs for the conversion. I'll use the standard Beta equation with typical 10kΩ NTC values — change the three constants to match your part's datasheet. ```python import board, busio, digitalio import adafruit_mcp3xxx.mcp3008 as MCP from adafruit_mcp3xxx.analog_in import AnalogIn import math # Your thermistor + divider. Change to match your datasheet/wiring. R_FIXED = 10_000.0 # series resistor (ohms) R0 = 10_000.0 # thermistor resistance at 25 °C BETA = 3950.0 # Beta constant (K) T0 = 298.15 # 25 °C in kelvin _mcp = MCP.MCP3008(busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO), digitalio.DigitalInOut(board.D5)) _chan = AnalogIn(_mcp, MCP.P0) def read_temperature_c(): """Temperature in °C from an NTC thermistor on MCP3008 channel 0.""" v = _chan.voltage if v <= 0 or v >= _chan.reference_voltage: # rail = open or shorted sensor raise ValueError(f"thermistor reading at rail ({v:.3f} V): check wiring") # Divider: 3V3 -- R_FIXED -- node(ADC) -- thermistor -- GND r_therm = R_FIXED * v / (_chan.reference_voltage - v) inv_t = 1 / T0 + math.log(r_therm / R0) / BETA # Beta equation return 1 / inv_t - 273.15 ``` ```python # self-check (no hardware): node voltage at exactly 25 °C must give 25 °C back. if __name__ == "__main__": vref = 3.3 v_at_25 = vref * R0 / (R_FIXED + R0) r = R_FIXED * v_at_25 / (vref - v_at_25) t = 1 / (1 / T0 + math.log(r / R0) / BETA) - 273.15 assert abs(t - 25.0) < 0.01, t print("ok") ``` This assumes the wiring **thermistor to GND, fixed resistor to 3V3**. If yours is the other way around, swap to `r_therm = R_FIXED * (vref - v) / v`. Skipped: averaging/filtering noisy readings, and CS/SPI pin config beyond the common defaults (D5 chip-select) — change `board.D5` to your CS pin. Risk: the three constants and the divider orientation are guesses; wrong values give a plausible-but-wrong temperature, so verify against your datasheet.

Output

Using the standard `gpiozero` library (already supports MCP3008) rather than hand-rolling SPI. ```python from gpiozero import MCP3008 from math import log # Beta-equation thermistor read. Calibrate the constants below to YOUR part. # Defaults: 10k NTC, 10k series resistor, 3.3V ref, Beta=3950, 25C nominal. def read_celsius(channel=0, vref=3.3, r_series=10000, r_nominal=10000, t_nominal=25, beta=3950): adc = MCP3008(channel=channel) v = adc.value * vref # gpiozero gives 0..1 if v <= 0 or v >= vref: raise ValueError(f"ADC rail reading {v:.3f}V: check wiring") r_therm = r_series * v / (vref - v) # thermistor on low side, divider to GND inv_t = 1/(t_nominal + 273.15) + log(r_therm / r_nominal) / beta return 1/inv_t - 273.15 ``` Quick self-check (no hardware, Steinhart math at the nominal point): ```python if __name__ == "__main__": # At r_therm == r_nominal the formula must return t_nominal. import math beta, r_nom, t_nom = 3950, 10000, 25 inv_t = 1/(t_nom+273.15) + math.log(r_nom/r_nom)/beta assert abs((1/inv_t - 273.15) - t_nom) < 1e-9 print("math ok") ``` What I skipped / risks: - **Calibration is yours**: the Beta, nominal resistance, series resistor and divider orientation (I assumed thermistor-to-GND) must match your actual circuit, or readings are wrong. Flip the `r_therm` line if your thermistor is on the high side. - Didn't test on real hardware; assumes `gpiozero` is installed and SPI is enabled (`raspi-config`). No averaging/smoothing — add it if your ADC is noisy.

Output

**What's your setup?** Before I write anything, I need to know: 1. **How do you identify users?** (IP address, API key, JWT `sub`, something else?) 2. **What limit?** (e.g. "10 requests per minute") 3. **Do you have Redis?** If not, are multiple workers/processes involved? --- **While you answer — the honest options:** | Option | When it fits | |---|---| | **In-process dict** (zero deps) | Single worker, stateless restart is fine, IP or key auth | | **`slowapi`** (thin `limits` wrapper) | Already have it, or want per-route decorators fast | | **Redis + `limits`** | Multiple workers, limits must survive restarts | The smallest thing that fully works is the **in-process dict with a sliding window** — ~15 lines, no new dependencies, one decorator you drop on any route. It is the right call for a single-worker app. If you have multiple workers, you need Redis; I won't fake distributed state with a local dict. --- **Skipped:** per-route vs. global config, custom error bodies, burst allowance, and dependency injection wiring (will add once I know your auth shape). **Risk:** if you are already running `slowapi` or `limits`, tell me — no point adding parallel rate-limiting logic.