# Example OpenAI Session: Temperature Sensor Board

This document demonstrates using GPT-4 with kicad-tools to design a simple I2C temperature sensor board.

## Project Requirements

- I2C temperature sensor (TMP102)
- 3.3V power from external supply
- Connector for I2C bus
- LED indicator for power
- 2-layer PCB, JLCPCB manufacturing

## Session Transcript

### User Request

> Design a small I2C temperature sensor board using the TMP102. It should have a 4-pin connector for power and I2C, plus a power LED.

### GPT-4 Response

I'll create a temperature sensor board with the TMP102. Let me set up the schematic first.

#### Function Calls - Schematic Setup

```json
// Add power rails
{"name": "add_power_symbol", "arguments": {"symbol": "+3V3", "x": 100, "y": 20}}
{"name": "add_power_symbol", "arguments": {"symbol": "GND", "x": 100, "y": 140}}
```

Response:
```json
{"status": "success", "message": "Added +3V3 at (100, 20)"}
{"status": "success", "message": "Added GND at (100, 140)"}
```

```json
// Add I2C connector
{
    "name": "add_schematic_symbol",
    "arguments": {
        "lib_id": "Connector_Generic:Conn_01x04",
        "x": 40,
        "y": 80,
        "reference": "J1",
        "value": "I2C_CONN"
    }
}
```

Response:
```json
{
    "status": "success",
    "component": {
        "ref": "J1",
        "pins": ["1", "2", "3", "4"],
        "position": [40, 80]
    }
}
```

```json
// Add TMP102 temperature sensor
{
    "name": "add_schematic_symbol",
    "arguments": {
        "lib_id": "Sensor_Temperature:TMP102",
        "x": 100,
        "y": 80,
        "reference": "U1",
        "value": "TMP102"
    }
}
```

Response:
```json
{
    "status": "success",
    "component": {
        "ref": "U1",
        "pins": ["VCC", "GND", "SDA", "SCL", "ALERT", "ADD0"],
        "position": [100, 80]
    }
}
```

```json
// Add power LED indicator
{
    "name": "add_led_indicator",
    "arguments": {
        "x": 150,
        "y": 80,
        "ref_prefix": "D1",
        "label": "PWR",
        "resistor_value": "1k"
    }
}
```

Response:
```json
{
    "status": "success",
    "block": {
        "components": ["D1", "R1"],
        "ports": {"VCC": [150, 72.5], "GND": [150, 95]}
    }
}
```

```json
// Add decoupling capacitor
{
    "name": "add_decoupling_caps",
    "arguments": {
        "x": 85,
        "y": 55,
        "ref_start": "C1",
        "values": ["100nF"]
    }
}
```

Response:
```json
{
    "status": "success",
    "components": [{"ref": "C1", "value": "100nF", "position": [85, 55]}]
}
```

#### Function Calls - Wiring

```json
// Wire connector to power and I2C
{"name": "wire_components", "arguments": {"from_ref": "J1", "from_pin": "1", "to_ref": "+3V3", "to_pin": "1"}}
{"name": "wire_components", "arguments": {"from_ref": "J1", "from_pin": "2", "to_ref": "GND", "to_pin": "1"}}
{"name": "wire_components", "arguments": {"from_ref": "J1", "from_pin": "3", "to_ref": "U1", "to_pin": "SDA"}}
{"name": "wire_components", "arguments": {"from_ref": "J1", "from_pin": "4", "to_ref": "U1", "to_pin": "SCL"}}
```

```json
// Wire TMP102 power
{"name": "wire_components", "arguments": {"from_ref": "U1", "from_pin": "VCC", "to_ref": "+3V3", "to_pin": "1"}}
{"name": "wire_components", "arguments": {"from_ref": "U1", "from_pin": "GND", "to_ref": "GND", "to_pin": "1"}}
```

```json
// Configure TMP102 address (tie ADD0 to GND for 0x48)
{"name": "wire_components", "arguments": {"from_ref": "U1", "from_pin": "ADD0", "to_ref": "GND", "to_pin": "1"}}
```

#### Function Calls - Save Schematic

```json
{
    "name": "list_symbols",
    "arguments": {}
}
```

Response:
```json
{
    "symbols": [
        {"ref": "J1", "value": "I2C_CONN", "lib_id": "Connector_Generic:Conn_01x04"},
        {"ref": "U1", "value": "TMP102", "lib_id": "Sensor_Temperature:TMP102"},
        {"ref": "D1", "value": "PWR", "lib_id": "Device:LED"},
        {"ref": "R1", "value": "1k", "lib_id": "Device:R"},
        {"ref": "C1", "value": "100nF", "lib_id": "Device:C"}
    ]
}
```

```json
{
    "name": "save_schematic",
    "arguments": {"file_path": "temp_sensor.kicad_sch"}
}
```

Response:
```json
{"status": "success", "file": "temp_sensor.kicad_sch", "components": 5, "nets": 6}
```

#### Function Calls - PCB Layout

```json
{
    "name": "load_pcb",
    "arguments": {"file_path": "temp_sensor.kicad_pcb"}
}
```

Response:
```json
{
    "status": "success",
    "board": {
        "width": 25,
        "height": 20,
        "layers": 2,
        "components": 5,
        "unrouted_nets": 6
    }
}
```

```json
// Place connector at edge
{
    "name": "place_component",
    "arguments": {"ref": "J1", "x": 3, "y": 10, "rotation": 270}
}

// Place TMP102 centrally
{
    "name": "place_component",
    "arguments": {"ref": "U1", "x": 12, "y": 10}
}

// Place decoupling cap near U1
{
    "name": "place_component",
    "arguments": {"ref": "C1", "x": 12, "y": 5}
}

// Place LED at visible location
{
    "name": "place_component",
    "arguments": {"ref": "D1", "x": 20, "y": 8}
}

{
    "name": "place_component",
    "arguments": {"ref": "R1", "x": 20, "y": 12}
}
```

#### Function Calls - Routing

```json
// Route power nets with wide traces
{
    "name": "route_net",
    "arguments": {
        "net": "+3V3",
        "prefer_layer": "F.Cu",
        "trace_width": 0.4
    }
}
```

Response:
```json
{
    "status": "success",
    "net": "+3V3",
    "connections": 4,
    "length_mm": 22.5,
    "vias": 0
}
```

```json
// Route ground with plane on bottom layer
{
    "name": "define_zone",
    "arguments": {
        "net": "GND",
        "layer": "B.Cu",
        "priority": 0
    }
}
```

Response:
```json
{
    "status": "success",
    "zone": "GND",
    "layer": "B.Cu",
    "coverage": "95%"
}
```

```json
// Route I2C signals
{
    "name": "route_net",
    "arguments": {
        "net": "SDA",
        "prefer_layer": "F.Cu",
        "minimize_vias": true
    }
}

{
    "name": "route_net",
    "arguments": {
        "net": "SCL",
        "prefer_layer": "F.Cu",
        "minimize_vias": true
    }
}
```

#### Function Calls - Validation

```json
{
    "name": "check_drc",
    "arguments": {
        "manufacturer": "jlcpcb",
        "layers": 2
    }
}
```

Response:
```json
{
    "status": "success",
    "errors": 0,
    "warnings": 1,
    "details": {
        "warnings": [
            {"type": "silk_clearance", "location": [20, 8], "message": "Silkscreen close to pad"}
        ]
    },
    "checks_passed": ["clearance", "trace_width", "via_size", "annular_ring"]
}
```

The warning is non-critical. Let's proceed.

```json
{
    "name": "save_pcb",
    "arguments": {"file_path": "temp_sensor.kicad_pcb"}
}
```

#### Function Calls - Export

```json
{
    "name": "extract_bom",
    "arguments": {"format": "markdown", "group_by": "value"}
}
```

Response:
```markdown
| Qty | Value | Reference | Footprint |
|-----|-------|-----------|-----------|
| 1 | I2C_CONN | J1 | Connector_PinHeader_2.54mm:PinHeader_1x04 |
| 1 | TMP102 | U1 | Package_TO_SOT_SMD:SOT-563 |
| 1 | PWR | D1 | LED_SMD:LED_0603 |
| 1 | 1k | R1 | Resistor_SMD:R_0402 |
| 1 | 100nF | C1 | Capacitor_SMD:C_0402 |
```

```json
{
    "name": "export_gerbers",
    "arguments": {
        "output_dir": "./gerbers",
        "manufacturer": "jlcpcb"
    }
}
```

Response:
```json
{
    "status": "success",
    "files": [
        "temp_sensor-F_Cu.gbr",
        "temp_sensor-B_Cu.gbr",
        "temp_sensor-F_Mask.gbr",
        "temp_sensor-B_Mask.gbr",
        "temp_sensor-F_Silkscreen.gbr",
        "temp_sensor-Edge_Cuts.gbr",
        "temp_sensor.drl"
    ],
    "output_dir": "./gerbers"
}
```

### Summary

I've created a complete I2C temperature sensor board:

**Schematic Components:**
- J1: 4-pin connector (VCC, GND, SDA, SCL)
- U1: TMP102 temperature sensor
- C1: 100nF decoupling capacitor
- D1/R1: Power LED with 1k resistor

**PCB Specifications:**
- Size: 25mm x 20mm
- Layers: 2
- Ground plane on bottom layer
- DRC: Passed (JLCPCB rules)

**Files Generated:**
- `temp_sensor.kicad_sch` - Schematic
- `temp_sensor.kicad_pcb` - PCB layout
- `./gerbers/` - Manufacturing files

The design is ready for ordering from JLCPCB!
