# Cheatsheet

## Environment Setup

```bash
source ~/esp/esp-idf/export.sh          # Activate ESP-IDF (every shell)
```

## Build & Flash

```bash
cd ~/git/esp32-hacking/get-started/csi_recv_router

idf.py set-target esp32                 # Set chip target
idf.py menuconfig                       # Configure WiFi/UDP settings
idf.py build                            # Compile firmware
idf.py -p /dev/ttyUSB0 flash            # Flash to device
idf.py -p /dev/ttyUSB0 monitor          # Serial monitor (Ctrl+] to exit)
idf.py -p /dev/ttyUSB0 flash monitor    # Flash + monitor combined
idf.py fullclean                        # Clean build directory
idf.py reconfigure                      # Re-fetch managed components
```

## Deployed Sensors

| Name | IP | Location |
|------|-----|----------|
| muddy-storm | 192.168.129.29 | Living Room |
| amber-maple | 192.168.129.30 | Office |
| hollow-acorn | 192.168.129.31 | Kitchen |

**Target:** `192.168.129.11:5500` (Pi)

## Test CSI Reception

```bash
nc -lu 5500                             # Listen for CSI packets
socat UDP-RECV:5500 STDOUT              # Alternative listener
nc -lu 5500 | head -1                   # See one packet
nc -lu 5500 | wc -l                     # Count packets/sec (Ctrl+C)
```

## Firmware Variants

| Firmware | Dir | Output | Needs |
|----------|-----|--------|-------|
| csi_recv_router | `get-started/csi_recv_router/` | UDP | WiFi router |
| csi_recv | `get-started/csi_recv/` | Serial | csi_send device |
| csi_send | `get-started/csi_send/` | N/A | csi_recv device |

## Key Config (menuconfig)

| Path | Setting |
|------|---------|
| Example Connection Configuration → SSID | WiFi network name |
| Example Connection Configuration → Password | WiFi password |
| CSI UDP Configuration → IP | `192.168.129.11` |
| CSI UDP Configuration → Port | `5500` |

## CSI Data Format

```
CSI_DATA,seq,mac,rssi,rate,sig_mode,mcs,cwb,smoothing,not_sounding,
aggregation,stbc,fec_coding,sgi,noise_floor,ampdu_cnt,channel,
secondary_channel,timestamp,ant,sig_len,rx_state,len,first_word,"[I,Q,...]"
```

## Source Paths

| File | Purpose |
|------|---------|
| `get-started/csi_recv_router/main/app_main.c` | Main firmware source |
| `get-started/csi_recv_router/main/Kconfig.projbuild` | UDP target config |
| `get-started/csi_recv_router/sdkconfig.defaults` | SDK defaults |
| `get-started/csi_recv_router/main/idf_component.yml` | Dependencies |
| `get-started/csi_recv_router/CMakeLists.txt` | Build config |

## ESP-IDF Paths

| Path | Contents |
|------|----------|
| `~/esp/esp-idf/` | ESP-IDF v5.5.2 |
| `~/esp/esp-csi/` | Original esp-csi examples |
| `~/.espressif/tools/` | Xtensa toolchain |

## USB Serial

```bash
ls /dev/ttyUSB* /dev/ttyACM*            # Find connected devices
dmesg | tail                             # Check USB detection
sudo usermod -aG dialout $USER           # Fix permissions (re-login)
```