emb-loom

Catalog website: https://loom.pcbsmt.me

Reusable embedded drivers and algorithms. loom is a supply of tested building blocks: weave them into firmware, and keep product logic in the product repository.

Layout

operators/   pure algorithms, no I/O
drivers/     protocol/state-machine cores with a port.h
adapters/    MCU-specific register implementations (not portable)
patterns/    structure guides, not code
loom.json    unit index

The catalog currently contains fifty-nine units.

Operators:

• operators/filters/clamp — limit sample-to-sample change.
• operators/filters/median — remove impulses with an N-sample median.
• operators/filters/moving-average — smooth with an N-sample mean.
• operators/filters/ema — first-order lag with a power-of-two shift.
• operators/filters/trimmed-mean — drop min/max, then average a batch.
• operators/filters/mean — arithmetic mean of a batch.
• operators/filters/clamp-average — clamp, then moving average.
• operators/filters/weighted-average — weighted mean of a batch.
• operators/filters/clamp-debounce — clamp, then N-sample debounce.
• operators/debounce — stabilize a binary input.
• operators/hysteresis — keep state across a threshold band.
• operators/key-fsm — short and long key events.
• operators/crc16 — CRC-16/CCITT-FALSE.
• operators/ring-buffer — fixed-size byte ring buffer.
• operators/ir-nec-decode — NEC IR frame decoder.
• operators/pid — integer PID controller.
• operators/gamma-lut — interpolated lookup table.
• operators/crc32 — CRC-32/ISO-HDLC.
• operators/fixed-sqrt — Q16.16 square root.
• operators/biquad — Q15 direct-form I biquad.
• operators/fir — Q15 finite-impulse-response filter.
• operators/modbus-rtu — Modbus RTU frame builder and parser.
• operators/pir — PIR motion signal chain.

Drivers:

• drivers/i2c-master — blocking I2C master core with a port and fake bus.
• drivers/uart — blocking UART core with a port and timeout.
• drivers/ws2812 — RGB to GRB encoder with a timing port.
• drivers/ir-capture — falling-edge interval collector for IR receivers.
• drivers/adc-sampler — averaged ADC reads.
• drivers/soft-pwm — software PWM on one pin.
• drivers/ds18b20 — DS18B20 temperature over 1-Wire.
• drivers/ssd1306 — SSD1306 128x64 I2C display.
• drivers/dht — DHT11/DHT22 frame decoders.
• drivers/rotary-encoder — Quadrature decoder.
• drivers/at24cxx — AT24Cxx I2C EEPROM.
• drivers/ds3231 — DS3231 I2C real-time clock.
• drivers/max7219 — MAX7219/MAX7221 SPI LED driver.
• drivers/pca9685 — PCA9685 16-channel I2C PWM.
• drivers/mpu6050 — MPU-6050 six-axis IMU.
• drivers/sht3x — SHT30/SHT31/SHT35 temperature and humidity.
• drivers/aht20 — AHT20 temperature and humidity.
• drivers/mcp2515 — MCP2515 CAN controller.
• drivers/stepper — A4988/DRV8825 step/direction driver.
• drivers/hx711 — HX711 24-bit load-cell amplifier.
• drivers/max31855 — MAX31855 thermocouple amplifier.
• drivers/bme280 — BME280 temperature, pressure, and humidity.
• drivers/adxl345 — ADXL345 three-axis accelerometer.
• drivers/mcp23017 — MCP23017 16-bit I/O expander.
• drivers/ads1115 — ADS1115 16-bit ADC.
• drivers/sh1106 — SH1106 128x64 I2C OLED.
• drivers/mcp4725 — MCP4725 12-bit DAC.
• drivers/pcf8574 — PCF8574 8-bit I/O expander.
• drivers/hc-sr04 — HC-SR04 ultrasonic distance.
• drivers/ina219 — INA219 current/power monitor.
• drivers/mcp9808 — MCP9808 temperature sensor.
• drivers/nrf24l01 — nRF24L01+ 2.4 GHz SPI transceiver.
• drivers/hd44780 — HD44780 character LCD.
• drivers/mfrc522 — MFRC522 13.56 MHz RFID reader.
• drivers/scd4x — SCD40/SCD41 CO2 sensor.
• drivers/sdcard — SD card block device over SPI.

Contract

• C99, no malloc, no vendor headers, no I/O in operators.
• The caller owns storage; no hidden globals.
• Each unit carries host tests and a short contract in its README.
• MIT licensed.

Test

make test

Use

Copy the selected unit into the product tree, keep its provenance, and call the public API. Adapters for a specific MCU stay next to the product.

Versioning

loom.json lists unit versions. A project pins exact versions and file hashes in its own lock file.