# Zephyr Sand Table firmware

This repository contains the implementation of Sand Table firmware for the Zephyr RTOS.

The firmware controls 2x stepper motors and RGBW LED strip.

### BUILD

```
west build -p -b arduino_nano_connect
```

### ACK

Every command returns either an ACK or NACK.

Homing, Step, and Polar commands return separate ACK when the arms are done moving.

### Command Structure

```c
struct command_message_t {
    uint8_t prefix;     // 0x69
    uint8_t length;		// Length of the data
    uint8_t id;			// 0x00
    uint8_t command;
    uint8_t crc;
    uint8_t data[160];
} __attribute__((packed));
```

### Commands

```c
typedef enum {
	COMMAND_ACK,
	COMMAND_NACK,
	COMMAND_LED,
	COMMAND_HOME,
	COMMAND_DISABLE_MOTORS,
	COMMAND_MOTOR_STEP,
	COMMAND_MOTOR_SPEED,
	COMMAND_POLAR,
	COMMAND_GET_POLAR,
	COMMAND_SET_OFFSET,
	COMMAND_RESET_OFFSET,
} commands_e;
```

### Python test scripts (AI generated)

* `home.py` = sends homing command
* `led.py` = sends led command which sends led fade track
* `position.py` = sends position command and returns the current position
* `reset_offset.py` = sends reset_offset command
* `track.py {track name}` = reads a thetarho file and sends polar coordinates line by line