Trail Searching + Hindrance Detecting Mini-Bot 尋軌跡/避障礙智能小車

Model Pack with sensor/input/output


Product Description

Trail searching, obstacle detection, distance sensing. 3 models.    

With this construction set you can build and control a number of interesting Mini Bots; our pet name for mobile robots. 


See online guide for the mini-bot here

See micro:bit coding with input and output guides here.



trail seeker

obstacle detector

mobile device as to remote

datalogging with BBC micro:bit and Mini Bots


  • All model parts can be reused and recycled for other projets and student's creative pieces.    fischertechnik is made in Germany with quality and precision.
  • No soldering.  Ideal for all ages, promote problem solving, changes on the fly as debugging and adjustment can be done instantly.    All works can be done to perfection as even the smallest adjustment can be accommodated, thanks to the 580+ mechanical/structural and electronic blocks offered by fischertechnik.



Hindrance  Detector

The Mini Bot hindrance detector is equipped with two mini-switches on the two bumpers which serve as sensors. After starting the program the Mini Bot moves straight ahead. It continues this until one of the bumpers touches an obstacle. If, for example, the left bumper, as seen when facing in the direction of motion, hits against a hindrance, it moves
 back a short distance. During this maneuver it also deviates by turning to the right, and then continues to move forwards. This deviating motion helps the Mini Bot to move around an obstacle or out of a corner.


Trail Searching

On the trail searcher model a further sensor, the trail sensor, is attached in addition to the two mini-switches acting as sensors on the two bumpers. With the aid of the trail sensor the Mini Bot trail searcher can follow a trail in the form of a black line. The mini-switches as sensors on the two bumpers serve for recognition of hindrances located along the black trail. If one of the two mini-switches is tripped by hitting against an obstacle, the Mini Bot trail searcher moves back, makes a deviating motion and then continues to move forward again while it looks for the black trail. An obstacle course is included in the construction set. A black trail is printed on it, which you can use for this model. For this purpose place the Mini Bot trail searcher in the middle of the obstacle course and switch on the power supply on the battery tray. The Mini Bot then moves forward in a spiral until it finds the black trail, which it then follows. However you can also draw a trail on a large sheet of white paper with a black marker. This black trail should be at least 20 mm wide for the trail sensor to work properly.

 Hindrance Detector with Trail Sensor

 As the name of this Mini Bot suggests, it is an upgraded version of the hindrance detector model with a trail sensor.  The mini-switches on the two bumpers serve as sensors. The trail sensor on this model is an additional sensor for recognition of hindrances in the form of a black line.  If the trail sensor recognizes a black line, the Mini Bot also moves back, deviates by turning and then continues to move forwards. 

The trail sensor consists of two transmitter and receiver elements as described under sensors. With the aid of these two transmitter and receiver elements the trail sensor can recognize how the Mini Bot makes contact with the black line acting as a hindrance and deviates accordingly. When, for example, the transmitter and receiver elements on the left side detect a black line first, the Mini Bot moves back while deviating to the right. In this case the trail sensor activates the same action as the mini-switches acting as sensors on the bumper.

You can also use the obstacle course from the construction set for the hindrance detector model with trail sensor. For this purpose place the Mini Bot in the middle of the obstacle course and switch on the power supply on the battery tray. The Mini Bot then continues to move forward until it touches a hindrance with the bumper or recognizes a black line with the trail sensor.





Part 1 - micro:bit block commands used in the Trail Searching and Hindrance Detecting Mini-Bot Model

To achieve fluency and competency in micro:bit coding, you really need to get a thorough understanding of each of the block catagories to be used in the Trail seeking and Hindrance Detecting Mini-bot Model (see part 2 below for the full code).    Fortunately, all the reference guides are available on the BBC micro:bit web site for you to get a deeper and more comprehensive understanding and mastery.

The Trail Searching and Hindrance Detecting Mini-Bot  Model used the following micro:bit blocks.  You can click to lean more about each of the block catagories.  The links bring you directly to the respective part of the BBC micro:bit reference document site, where live codes are included for you to understand, try, and download:



Part 2   The "live" Trail Searching and Hindrance Detecting Mini_bot  Code  - Understand, Edit and Download

  The following code has used all the mentioned blocks in Part 1 above.    


 Comments In English, click the " ? " on block to find out the comment (meaning) of the block code.

  • If you read this page on a computer with wider screen size, you will be able to see the micro:bit simulator that is fully clickable.
  • Click   to open the code on the micro:bit website for further editing and modification.
  • Click   to download this code to your micro:bit for immediate use or to save on your computer.     


Calibrating Forward and Backward

 If you cannot see the code, such as on a mobile phone, please  click this link instead.



Calibrating Left and Right

 If you cannot see the code, such as on a mobile phone, please  click this link instead.



Hindrance Detection

 If you cannot see the code, such as on a mobile phone, please  click this link instead.


Trail Seeking

 If you cannot see the code, such as on a mobile phone, please  click this link instead.


Order options
ADD: I/O board at HK$ 199
ADD: micro:bit at HK$ 135
HK$ 760.00

Model Part / No I/O board / No micro:bit