PCB block diagram

{
  "nodes": [
    { "id":"mcu","type":"rect","label":"MCU","x":420,"y":220,"fill":"#ede9fe","stroke":"#6d28d9" },
    { "id":"pwr","type":"rect","label":"Power reg.","x":40,"y":40,"fill":"#fee2e2","stroke":"#b91c1c" },
    { "id":"bat","type":"rect","label":"Battery","x":40,"y":160,"fill":"#fee2e2","stroke":"#b91c1c" },
    { "id":"imu","type":"rect","label":"IMU","x":40,"y":280,"fill":"#dbeafe","stroke":"#2563eb" },
    { "id":"sd","type":"rect","label":"SD card","x":40,"y":400,"fill":"#dbeafe","stroke":"#2563eb" },
    { "id":"ble","type":"rect","label":"BLE radio","x":820,"y":40,"fill":"#dcfce7","stroke":"#15803d" },
    { "id":"usb","type":"rect","label":"USB-C","x":820,"y":160,"fill":"#dcfce7","stroke":"#15803d" },
    { "id":"led","type":"rect","label":"RGB LEDs","x":820,"y":280,"fill":"#fef3c7","stroke":"#a16207" },
    { "id":"jtag","type":"rect","label":"JTAG / SWD","x":820,"y":400,"fill":"#e2e8f0","stroke":"#475569" }
  ],
  "edges": [
    { "id":"a","source":"bat","target":"pwr" },
    { "id":"b","source":"pwr","target":"mcu","label":"3V3" },
    { "id":"c","source":"imu","target":"mcu","label":"SPI" },
    { "id":"d","source":"sd","target":"mcu","label":"SDIO" },
    { "id":"e","source":"mcu","target":"ble","label":"UART" },
    { "id":"f","source":"mcu","target":"usb","label":"USB" },
    { "id":"g","source":"mcu","target":"led","label":"PWM" },
    { "id":"h","source":"mcu","target":"jtag" }
  ]
}