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https://github.com/Vidicon/camsense-X1
unofficial reverse engineering of a Chinese LiDAR. Discussed this on my discord: https://discord.gg/zRGJcqa
https://github.com/Vidicon/camsense-X1
Last synced: about 2 months ago
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unofficial reverse engineering of a Chinese LiDAR. Discussed this on my discord: https://discord.gg/zRGJcqa
- Host: GitHub
- URL: https://github.com/Vidicon/camsense-X1
- Owner: Vidicon
- License: gpl-3.0
- Created: 2020-04-14T12:56:27.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2020-10-03T22:59:44.000Z (almost 4 years ago)
- Last Synced: 2024-05-04T22:33:21.691Z (5 months ago)
- Size: 6.18 MB
- Stars: 48
- Watchers: 9
- Forks: 9
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# camsense-X1
unofficial reverse engineering of a Chinese LiDAR.
Discussed this on my discord: https://discord.gg/zRGJcqa
ROS1 driver for the camsense-X1: https://github.com/Vidicon/camsense_driver Made by [Vidicon](https://github.com/vidicon) (Bram Fenijn)
ROS2 driver for the camsense-X1: https://github.com/rossihwang/ros2_camsense_x1 Made by [rossihwang](https://github.com/rossihwang)
implementation for a STM32: https://github.com/anhui1995/Camsense_X1
Read the LiDAR with a M5Stack: https://github.com/yishii/LiDAR_Camsense_X1_M5Stack Made by [yishii](https://github.com/yishii)
*Your opensource camsense-X1 project here? Please let me know.*
## Dimensions
The dimensions(mm) of the Camsense-x1 mounting holes:
I have made a 3d model of the LiDAR: [stl](Camsense_X1.stl), [step](camsense_x1.step) (Dimensions are approximate)
## Electrical Connections
There are 3 pins needed to connect to the lidar: 5V, GND and TX. For this you can use the mounted connector(part number unknown) or solder some pinheader to the pcb.
The tx pin sends serial data with 115200 baud at a signal level of 3.3v This make the lidar safe to be connected directly to a 3.3v microcontroller of SBC like the STM32 or Raspberry Pi
A FTDI adapter can be used to connect the LiDAR to a computer. The TX pin of the LiDAR needs to be connected to the RX pin of th FTDI adapter. The LiDAR can be powered using the 5V of the FTDI adapter.
## Communication Protocol
The lidar sends on average 50 packages per rotation of the sensor. A package is always 36 bytes and has the following format:
<0x55><0xAA><0x03><0x08>
\\
\\
\\\
\\\
\\\
\\\
\\\
\\\
\\\
\\\
\\
\\ could be a CRC
A package always starts with <0x55><0xAA><0x03><0x08>
Calculate rotation speed in hz:
```c++
float Hz = ((uint16_t) (speedH << 8) | speedL) / 3840.0; // 3840.0 = (64 * 60)
```
Calculate start and end Angle in degrees:
```c++
float startAngle = (startAngleH << 8 | startAngleL) / 64.0 - 640.0;
float endAngle = (endAngleH << 8 | endAngleL) / 64.0 - 640.0;
```
Best method we found to calculate index and parse data to array:
```c++
float offset_ = 16.0; // 0 degrees seems to be 16 degrees of center.
const float IndexMultiplier = 400 / 360.0;
float step = 0.0;
if(endAngle > startAngle)
{
step = (endAngle - startAngle) / 8;
}
else
{
step = (endAngle - (startAngle - 360)) / 8;
}
for(int i = 0; i < 8; i++) // for each of the 8 samples
{
float sampleAngle = (startAngle + step * i) + (offset_ + 180);
float sampleIndexFloat = sampleAngle * IndexMultiplier; // map 0-360 to 0-400
int sampleIndex = round(sampleIndexFloat); // round to closest value.
index = sampleIndex % 400; // limit sampleIndex between 0 and 399 to prevent segmentation fault
uint8_t distanceL = data[8+(i*3)];
uint8_t distanceH = data[9+(i*3)];
uint8_t quality = data[10+(i*3)];
if(quality == 0) // invalid data
{
distanceArray[index] = 0;
qualityArray[index] = 0;
}
else
{
distanceArray[index] = ((uint16_t) distanceH << 8) | distanceL;
qualityArray[index] = quality;
}
}
```