abse/museair-usb

validation/schematic-annotations.json

{
  "sheets": {
    "POWER": "01 / USB-C and power",
    "CONTROLLER": "02 / ESP32 controller and boot",
    "SENSOR": "03 / Air sensor and I2C",
    "INTERFACES": "04 / Controls and programming",
    "MICROPHONE": "05 / Top-port microphone and ADC",
    "SPEAKER": "06 / Speaker amplifier and JST lead",
    "DISPLAY": "07 / Colour display and I2C controls"
  },
  "components": {
    "J1": {
      "sheet": "POWER",
      "explanation": "USB-C 5 V input; power only"
    },
    "R1": {
      "sheet": "POWER",
      "explanation": "CC1: enables USB-C power"
    },
    "R2": {
      "sheet": "POWER",
      "explanation": "CC2: enables USB-C power"
    },
    "C1": {
      "sheet": "POWER",
      "explanation": "Filters USB input"
    },
    "U2": {
      "sheet": "POWER",
      "explanation": "Efficient 3.3 V buck for ESP"
    },
    "C2": {
      "sheet": "POWER",
      "explanation": "Buck input reservoir"
    },
    "C3": {
      "sheet": "POWER",
      "explanation": "Buck output reservoir"
    },
    "U4": {
      "sheet": "POWER",
      "explanation": "3.3 V regulator for sensor"
    },
    "C4": {
      "sheet": "POWER",
      "explanation": "U4 input reservoir"
    },
    "C8": {
      "sheet": "POWER",
      "explanation": "Sensor bulk reserve"
    },
    "C9": {
      "sheet": "POWER",
      "explanation": "Sensor noise bypass"
    },
    "C10": {
      "sheet": "POWER",
      "explanation": "Sensor transient reserve"
    },
    "U1": {
      "sheet": "CONTROLLER",
      "explanation": "Wi-Fi / BLE controller"
    },
    "C5": {
      "sheet": "CONTROLLER",
      "explanation": "ESP current reserve"
    },
    "C6": {
      "sheet": "CONTROLLER",
      "explanation": "ESP noise bypass"
    },
    "R4": {
      "sheet": "CONTROLLER",
      "explanation": "Keeps ESP enabled"
    },
    "C7": {
      "sheet": "CONTROLLER",
      "explanation": "Delays power-on reset"
    },
    "R5": {
      "sheet": "CONTROLLER",
      "explanation": "GPIO8 boot pullup"
    },
    "R6": {
      "sheet": "CONTROLLER",
      "explanation": "Normal-boot pullup"
    },
    "R7": {
      "sheet": "CONTROLLER",
      "explanation": "GPIO2 boot pullup"
    },
    "SW2": {
      "sheet": "CONTROLLER",
      "explanation": "Press to reset ESP"
    },
    "SW3": {
      "sheet": "CONTROLLER",
      "explanation": "Hold for flashing"
    },
    "J3": {
      "sheet": "SENSOR",
      "explanation": "GH-6 cable to SEN62"
    },
    "R8": {
      "sheet": "SENSOR",
      "explanation": "SDA idle-high pullup"
    },
    "R9": {
      "sheet": "SENSOR",
      "explanation": "SCL idle-high pullup"
    },
    "J5": {
      "sheet": "SENSOR",
      "explanation": "Optional I2C test pads"
    },
    "U3": {
      "sheet": "SENSOR",
      "explanation": "Laser PM, humidity and temperature"
    },
    "J4": {
      "sheet": "INTERFACES",
      "explanation": "Optional UART test pads"
    },
    "R3": {
      "sheet": "INTERFACES",
      "explanation": "ASK idle-high pullup"
    },
    "SW1": {
      "sheet": "INTERFACES",
      "explanation": "Raised ASK / pair actuator"
    },
    "R10": {
      "sheet": "INTERFACES",
      "explanation": "Limits LED current"
    },
    "D1": {
      "sheet": "INTERFACES",
      "explanation": "Firmware status light"
    },
    "TPG1": {
      "sheet": "INTERFACES",
      "explanation": "Ground probe point"
    },
    "TPG2": {
      "sheet": "INTERFACES",
      "explanation": "Ground probe point"
    },
    "TPG3": {
      "sheet": "INTERFACES",
      "explanation": "Ground probe point"
    },
    "J6": {
      "sheet": "INTERFACES",
      "explanation": "Plug-in SH-3 UART programmer"
    },
    "L1": {
      "sheet": "POWER",
      "explanation": "Buck energy-storage inductor"
    },
    "C11": {
      "sheet": "POWER",
      "explanation": "Buck bootstrap capacitor"
    },
    "C12": {
      "sheet": "POWER",
      "explanation": "Additional buck output reserve"
    },
    "MIC1": {
      "sheet": "MICROPHONE",
      "explanation": "Top-port MEMS microphone, 65 dBA SNR"
    },
    "U5": {
      "sheet": "MICROPHONE",
      "explanation": "Microphone preamp, gain 51"
    },
    "R11": {
      "sheet": "MICROPHONE",
      "explanation": "Filters microphone supply"
    },
    "C13": {
      "sheet": "MICROPHONE",
      "explanation": "Microphone supply reservoir"
    },
    "C14": {
      "sheet": "MICROPHONE",
      "explanation": "C0G microphone bypass, 100 nF"
    },
    "C15": {
      "sheet": "MICROPHONE",
      "explanation": "C0G microphone DC blocking"
    },
    "C16": {
      "sheet": "MICROPHONE",
      "explanation": "Parallel C0G microphone coupling"
    },
    "R12": {
      "sheet": "MICROPHONE",
      "explanation": "Biases microphone preamp input"
    },
    "R13": {
      "sheet": "MICROPHONE",
      "explanation": "Preamp feedback, 100 kohm"
    },
    "R14": {
      "sheet": "MICROPHONE",
      "explanation": "Preamp gain resistor, first 1 kohm"
    },
    "R15": {
      "sheet": "MICROPHONE",
      "explanation": "Preamp gain resistor, second 1 kohm"
    },
    "R16": {
      "sheet": "MICROPHONE",
      "explanation": "Bias divider upper resistor"
    },
    "R17": {
      "sheet": "MICROPHONE",
      "explanation": "Bias divider middle resistor"
    },
    "R18": {
      "sheet": "MICROPHONE",
      "explanation": "Bias divider lower resistor"
    },
    "C17": {
      "sheet": "MICROPHONE",
      "explanation": "Filters microphone bias"
    },
    "R19": {
      "sheet": "MICROPHONE",
      "explanation": "ADC input filter, 5.1 kohm"
    },
    "C18": {
      "sheet": "MICROPHONE",
      "explanation": "C0G ADC filter, 10 nF"
    },
    "U6": {
      "sheet": "SPEAKER",
      "explanation": "I2S class D speaker amplifier"
    },
    "C19": {
      "sheet": "SPEAKER",
      "explanation": "Speaker amplifier local bypass"
    },
    "C20": {
      "sheet": "SPEAKER",
      "explanation": "Speaker amplifier current reserve"
    },
    "J7": {
      "sheet": "SPEAKER",
      "explanation": "PicoBlade speaker plug, both pins driven"
    },
    "U7": {
      "sheet": "DISPLAY",
      "explanation": "I2C slow controls, address 0x38"
    },
    "C21": {
      "sheet": "DISPLAY",
      "explanation": "Expander local bypass"
    },
    "R20": {
      "sheet": "DISPLAY",
      "explanation": "Keeps display deselected at boot"
    },
    "R21": {
      "sheet": "DISPLAY",
      "explanation": "Keeps display reset released"
    },
    "R22": {
      "sheet": "SPEAKER",
      "explanation": "Keeps amplifier muted at boot"
    },
    "J8": {
      "sheet": "DISPLAY",
      "explanation": "10-pin 0.5 mm dual-contact display ZIF"
    },
    "C22": {
      "sheet": "DISPLAY",
      "explanation": "Display supply local bypass"
    },
    "C23": {
      "sheet": "DISPLAY",
      "explanation": "Display supply reserve"
    },
    "R24": {
      "sheet": "DISPLAY",
      "explanation": "Backlight limit, parallel resistor 1"
    },
    "R25": {
      "sheet": "DISPLAY",
      "explanation": "Backlight limit, parallel resistor 2"
    },
    "R26": {
      "sheet": "DISPLAY",
      "explanation": "Backlight limit, parallel resistor 3"
    }
  }
}