# Logistics Car Upper Computer AI Guide

## 1. Purpose
This document is written for an AI agent that will implement the upper computer application.
Goal: build a stable TCP client for the logistics car, with both auto mode and manual mecanum mode, based on the embedded protocol implemented in this repository.

Target users:
- AI coding agents (Copilot-like, AutoGen-like, etc.)
- Human developers who review AI-generated upper computer code

Out of scope:
- Modifying embedded firmware behavior
- Replacing transport protocol

---

## 2. Must-Follow Protocol Contract

### 2.1 Frame format
All commands and telemetry use ASCII text:

LOGI:<PAYLOAD>:<CS>#

Fields:
- LOGI: fixed header
- <PAYLOAD>: command or telemetry body
- <CS>: 2-digit uppercase hex checksum
- #: fixed frame tail

### 2.2 Checksum algorithm
Checksum is the low 8 bits of ASCII sum of all bytes from L in LOGI to the byte before the final colon before CS.

Pseudo:
1. base = "LOGI:" + payload
2. cs = sum(base bytes as ASCII) & 0xFF
3. frame = base + ":" + toHex2Upper(cs) + "#"

Python reference:

```python
def build_frame(payload: str) -> str:
    base = f"LOGI:{payload}"
    cs = sum(base.encode("ascii")) & 0xFF
    return f"{base}:{cs:02X}#"
```

C# reference:

```csharp
static string BuildFrame(string payload)
{
    string baseStr = $"LOGI:{payload}";
    int sum = 0;
    foreach (byte b in System.Text.Encoding.ASCII.GetBytes(baseStr))
        sum = (sum + b) & 0xFF;
    return $"{baseStr}:{sum:X2}#";
}
```

Important:
- Must use uppercase hex (for consistency)
- Do not append CRLF unless your socket tool requires it
- One frame can be sent as raw ASCII bytes directly

---

## 3. Command Set (PC -> Car)

### 3.1 Common control
- SP:xxx  set speed 000..100
- ST:RUN  start auto run
- ST:STOP stop run
- GS:xxx  set target station (current firmware supports 001, 002)

### 3.2 Mode switch (new)
- MD:MAN   switch to manual mecanum mode
- MD:AUTO  switch to auto tracking mode

### 3.3 Manual movement (new, only valid in MAN mode)
- MV:FWD   forward
- MV:BWD   backward
- MV:LEFT  strafe left
- MV:RIGHT strafe right
- MV:LF    forward-left diagonal
- MV:RF    forward-right diagonal
- MV:LB    backward-left diagonal
- MV:RB    backward-right diagonal
- MV:CW    rotate clockwise
- MV:CCW   rotate counterclockwise
- MV:STOP  stop motion

If current mode is AUTO and you send MV:*:
- car returns FB:MV:0 (rejected)
- upper computer must first send MD:MAN

---

## 4. Telemetry and Feedback (Car -> PC)

### 4.1 Periodic status (every ~500ms)
Payload format:

STAT:SP:xxx,STA:xxx,RUN:x,MODE:mode,MAN:dir,DIS:d,TRK:b4b3b2b1,DEV:n,OBS:x,RPM:m1:m2:m3:m4

Fields:
- SP: speed percent
- STA: target station
- RUN: 1 running, 0 stopped
- MODE: AUTO or MAN
- MAN: STOP/FWD/BWD/LEFT/RIGHT/LF/RF/LB/RB/CW/CCW
- DIS: ultrasonic distance in cm
- TRK: 4-channel line mask, order H4 H3 H2 H1
- DEV: track deviation (auto mode meaningful)
- OBS: obstacle lock (1 blocked, 0 clear)
- RPM: 4 motor RPM, order M1:M2:M3:M4 (LR:LF:RF:RR)

### 4.2 Command feedback (immediate)
Payload format:

FB:<CMD>:<0|1>

Examples:
- FB:SP:1  speed accepted
- FB:GS:0  station invalid or parse fail
- FB:MV:0  movement rejected (for example mode mismatch)

Upper computer rule:
- Every button operation should wait for feedback timeout window
- If no feedback in timeout, mark command uncertain and retry policy applies

---

## 5. Upper Computer Architecture Requirements

AI must implement the upper computer with these modules.

### 5.1 Network module
Responsibilities:
- Maintain TCP connection lifecycle
- Auto reconnect with backoff
- Byte stream receive and frame extraction

Required behavior:
- Reconnect delay: 1s, 2s, 3s, then fixed 3s
- On reconnect success, UI state set to Connected
- On disconnect, all movement buttons should be disabled

### 5.2 Protocol module
Responsibilities:
- Build frames from payload
- Parse incoming frames
- Verify checksum before dispatch

Required behavior:
- Drop frame if checksum invalid
- Log invalid frame raw text for diagnostics
- Expose strongly typed events: StatusEvent, FeedbackEvent

### 5.3 Command dispatcher
Responsibilities:
- Serialize outbound commands (single queue)
- Attach request id locally (not in protocol) for UI correlation
- Wait feedback with timeout

Recommended defaults:
- Feedback timeout: 800 ms
- Max retries for idempotent commands (SP, MD, MV:STOP): 2
- No auto-retry for ST:RUN and GS:xxx unless user confirms

### 5.4 UI module
Required controls:
- Connection: IP, port, connect/disconnect
- Mode: AUTO / MAN toggle
- Speed: slider 0..100 with send button
- Auto controls: station selector (001/002), RUN, STOP
- Manual controls: directional keypad + rotation + STOP
- Status panel: parsed telemetry fields
- Logs panel: TX/RX raw frames + parsed result

### 5.5 Safety guard module
Required safety logic:
- If UI in MAN mode and mouse/touch release on direction button, auto send MV:STOP
- If no fresh status for >2s, show stale warning
- Emergency stop hotkey sends MV:STOP first; if in AUTO also send ST:STOP

---

## 6. Exact Button-to-Command Mapping

All below are complete frames with checksum, directly sendable.

### 6.1 Mode
- Switch to manual: LOGI:MD:MAN:0C#
- Switch to auto: LOGI:MD:AUTO:69#

### 6.2 Speed presets
- 30%: LOGI:SP:030:D5#
- 50%: LOGI:SP:050:D7#
- 80%: LOGI:SP:080:DA#

### 6.3 Auto mode
- Station 001: LOGI:GS:001:CA#
- Station 002: LOGI:GS:002:CB#
- Auto run: LOGI:ST:RUN:3B#
- Auto stop: LOGI:ST:STOP:8C#

### 6.4 Manual movement
- Forward: LOGI:MV:FWD:23#
- Backward: LOGI:MV:BWD:1F#
- Left strafe: LOGI:MV:LEFT:6D#
- Right strafe: LOGI:MV:RIGHT:C0#
- Forward-left: LOGI:MV:LF:D4#
- Forward-right: LOGI:MV:RF:DA#
- Backward-left: LOGI:MV:LB:D0#
- Backward-right: LOGI:MV:RB:D6#
- Rotate CW: LOGI:MV:CW:DC#
- Rotate CCW: LOGI:MV:CCW:1F#
- Stop: LOGI:MV:STOP:88#

---

## 7. Recommended Operation Sequences

### 7.1 Manual driving flow
1. Connect TCP
2. Send SP:xxx
3. Send MD:MAN
4. Hold direction button -> send MV:* repeatedly or once per state change
5. Release button -> send MV:STOP

Recommended send style for manual:
- Edge-triggered (on press send once, on release send stop) is preferred
- If network jitter is high, add keepalive send of same MV every 300 ms

### 7.2 Auto transport flow
1. Connect TCP
2. Send SP:xxx
3. Send MD:AUTO
4. Send GS:001 or GS:002
5. Send ST:RUN
6. Observe RUN and feedback/status until arrival

Arrival behavior in firmware:
- Car auto-stops on target RFID
- RUN becomes 0
- Next run requires sending GS again, then ST:RUN

---

## 8. Frame Parsing Strategy (Stream-safe)

TCP is stream-based, not message-based. AI must implement frame extraction correctly.

Required parser behavior:
- Keep a receive buffer string/byte array
- Search for header "LOGI:"
- Search for tail '#'
- Extract candidate frame from first valid header to first following '#'
- Validate checksum
- Dispatch valid frame; remove consumed bytes
- If garbage before header, discard garbage

Do not assume one recv equals one frame.

---

## 9. Error Handling and Recovery

### 9.1 Feedback timeout
If command has no FB within timeout:
- Mark as timeout in UI
- For safe idempotent commands, retry once or twice
- For movement commands, prefer fail-safe by sending STOP

### 9.2 Checksum mismatch in received data
- Drop frame
- Log as warning with raw text
- Keep connection alive (do not disconnect directly)

### 9.3 Mode conflict
If receiving FB:MV:0 after sending MV command:
- UI should hint: "Not in manual mode, switching to MAN"
- Auto-send MD:MAN then retry once

### 9.4 Connection loss during motion
On disconnect event:
- UI enters safe state
- disable movement controls
- after reconnect, require operator to re-confirm mode and speed

---

## 10. AI Implementation Checklist (Definition of Done)

Functional:
- Can connect/disconnect TCP manually
- Can parse status and feedback reliably
- All buttons send correct command frames
- Manual control works in all listed directions
- Auto mode flow works (GS + RUN + STOP)

Robustness:
- Stream parser handles sticky packets and split packets
- Reconnect works automatically
- Command timeout/retry policy implemented
- Logs include TX/RX and parse errors

Usability:
- Telemetry fields visible and updating
- Mode and direction state clearly shown
- Emergency stop is always accessible

Testing:
- Unit test for checksum build/verify
- Unit test for parser with mixed/fragmented frames
- Integration test with mock TCP server replaying status/feedback

---

## 11. Suggested Prompt for Coding AI
Use this prompt when asking another coding AI to generate the upper computer:

"Implement a production-ready TCP upper computer client for an STM32 logistics car protocol. Use ASCII frame format LOGI:<PAYLOAD>:<CS># with checksum as sum(base bytes) & 0xFF where base is LOGI:<PAYLOAD>. Support commands SP, ST, GS, MD, MV. Parse status payload STAT with fields SP, STA, RUN, MODE, MAN, DIS, TRK, DEV, OBS, RPM. Parse feedback payload FB:<CMD>:<0|1>. Build a stream-safe parser for sticky/fragmented TCP packets. Include reconnect, timeout/retry, and a UI with manual mecanum directional controls and auto mode controls."

---

## 12. Notes for Future Extension
If firmware adds fields later:
- Keep parser tolerant: unknown key-value pairs should not crash parser
- Preserve raw payload in logs for forward compatibility
- Version your app-side parser module (for example v1_2)