https://github.com/laserborg/circuitpython_utils

https://github.com/laserborg/circuitpython_utils

Last synced: 8 days ago
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• Host: GitHub
• URL: https://github.com/laserborg/circuitpython_utils
• Owner: LaserBorg
• License: other
• Created: 2024-02-09T22:17:30.000Z (12 months ago)
• Default Branch: main
• Last Pushed: 2024-02-13T19:11:55.000Z (12 months ago)
• Last Synced: 2024-11-15T19:22:35.152Z (2 months ago)
• Language: Python
• Size: 18.6 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# CircuitPython Utilities

PiDAR CircuitPython-Version - CURRENTLY DISCONTINUED:

- CircuitPython optimized LD06 serial/UART driver

- CircuitPython optimized A4988 driver

Other:

- serial connection between host and board

- datarate-test

- BNO055 inertial navigation

## wiring

LD06 port (left to right)

- UART Tx, PWM, GND, 5V

Pico:

- LD06 UART0 Rx: GP1 (Pin2)

- LD06 PWM: GP2 (Pin4)

- LD06 5V: VBUS (Pin40)

- LD06 GND: e.g. Pin38

- A4988 direction: GP15 (pin20)

- A4988 step: GP14 (Pin19)

- A4988 microstepping: GP11, GP12, GP13 (Pin 15,16,17)

### Serial Protocol

baudrate 230400, data bits 8, no parity, 1 stopbit  

sampling frequency 4500, scan frequency 5-13 Hz, distance 2cm - 12 meter, ambient light 30 kLux

total package size: 48 Byte, big endian.

- starting character：Length 1 Byte, fixed value 0x54, means the beginning of data packet;

- Data Length: Length 1 Byte, the first three digits reserved, the last five digits represent the number of measured points in a packet, currently fixed value 12;

- speed：Length 2 Byte, in degrees per second;

- Start angle: Length: 2 Byte; unit: 0.01 degree;

- Data: Length 36 Byte; containing 12 data points with 3 Byte each: 2 Byte distance (unit: 1 mm), 1 Byte luminance. For white objects within 6m, the typical luminance is around 200.

- End Angle: Length: 2 Byte; unit: 0.01 degree；

- Timestamp: Length 2 Bytes in ms, recount if reaching to MAX 30000；

- CRC check: Length 1 Byte

The Angle value of each data point is obtained by linear interpolation of the starting angle and the ending angle.  

The calculation method of the angle is as following:

    step = (end_angle – start_angle)/(len – 1)  

    angle = start_angle + step*i  

len is the length of the packet, and the i value range is [0, len].