Open Simple LIDAR

Description

This is simple enough open source scanning laser rangefinder. It is using triangulation method.

It is based on my previous Lidar projects: http://hackaday.com/2016/06/05/in-soviet-russia-diy-laser-rangefinder-scan-you/ (https://github.com/iliasam/OpenLIDAR) and earlier lidar versions (in Russian): http://roboforum.ru/forum10/topic12095.html
Now I want to build really simple and cheap Lidar.

Details

Estimated Lidar parameters:

5 scans/second;

360 measurements per rotation (1 deg angle resolution);

Maximum distance - 4 m;

Calculated accuracy - 5 cm at 2 m, 10 cm at 3 m (I hope that it can be improved).

I suppose that price of all needed parts will be near $35.

Components

1 × TSL1401 Sensors / Image
1 × Slip Ring Used to pass power and signals to rotating scanning head.
1 × Main PCB PCB with most electronics parts
1 × Lens M12 lens, f'=16mm
1 × M12 Lens holder Standard M12 plastic leans holder

View all 13 components

Project Logs

Collapse logs

Programming and first tests
iliasam • 06/30/2017 at 11:00 • 0 comments

I have tested all PCB electronics, and everything is forking fine, so I can start to program MCU.
I have working code for my previous lidar - it was based on STM32F100 and TSL1401.
So I take code from that project and ported it to new STM32F030 MCU.
At first step I write testing firmware that capture analog signal from sensor to MCU memory and then transfer it PC by UART.
I write PC utility that draw illumination level of 128 sensor's pixels:
Here is a picture with IR laser that I want to use in final design:
The distance to object (white wall) was near 1.8 m.
The next step is printing laser holder and mounting it at PCB.
Electronics Assembly
iliasam • 06/20/2017 at 15:26 • 0 comments

Finally I get all electronic parts, so it's time to assemble PCB!
Photo of components used:
Most of them are easy enough to solder. The exception is light sensor - TSL1401CL; because pads of this sensor are placed under it's body.
Photo of assembled PCB:
Close view of soldered TSL1401:
Photo of PCB with leans installed:

3.5 mm Jack connector is used for STM32 programmer connection.
ST-Link utility found STM32 - so the next step is it's programming.
Firstly I need to run capturing data from light sensor.
P.S. I have updated Github files - I added some models, PCB schematic, gerber files.
Small model update
iliasam • 03/30/2017 at 19:12 • 0 comments

Now I found suitable encoder sensor for my Lidar - it is RPI-352. It can be bought at aliexpress.com or digikey.com.
I have added encoder ring to the model. I think that this ring must be metallic and have 15 drilled holes for light from sensor.
Encoder is important part of Lidar, it used to detect zero angle crossing and for rotation speed calculation.