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Showing posts from May, 2018

Mini Lidar for £11

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Well to be honest, a VL53L0X time of flight chip mounted on a small circuit board and then attached to a pan and tilt set-up positioned by 9g servos.



The data sheet for the VL53L0X chip is here.
Adafruit do a very nice little VL53L0Xboard although they can also be easily sourced from a number of suppliers. I downloaded the AdaFruit Arduino wrapper for the device library to get me started. Communication is over an I2C serial interface which keeps things straightforward. 
Connections from an Arduino are just to SDA and SCL as well as 5v and ground.
The tiny VL53L0X chip includes a 940nm VCSEL laser (Vertical Cavity Surface-Emitting Laser) fitted with infra-red filters giving reasonable immunity to ambient light interference. The laser is safe and will not damage eyesight. The device sends out a short laser pulse and measures the time taken for the light to be reflected back. The measurement range is up to 2 metres although the device is normally operated in one of 4 modes. There is a …

Sonar Scanner Part 2

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The second iteration of the sonar scanner (part 1 is here) has seen a switch to an Arduino Nano as the target board. This required soldering some pins to a piece of strip-board to allow multiple devices to take power from the limited 5v output available on the Nano. This allowed some simplification to the “rats nest” and the set-up as a “chip on the old block” as a precursor to any installation. The current layout made testing the revised software somewhat easier.


Here is a rather thrown together diagram of the connections. Not up to publication standards but hopefully clear enough for anyone interested.
The Arduino sonar scanner support software is now transformed into a state machine where each “task” set by a controlling processor over an I2C serial connection switches between states. The controlling (master) board can also request data from the Nano with the data returned being dependent upon the current state.
The idea is that it should be straightforward to introduce new option…