Yann Blake • Engineering

Projects | Ideas | Portfolio | Experiences

Robot Picaxe – [Project]

  • Project on the Picaxe Robot : assembling and customized manufacturing of the body part ; programming of the robot’s code
  • 1 year project in 2014 at Collège Jean Mounès School (France)
  • Competition between schools ending up in the best top 3
Robot Picaxe without the body

The BOT120 PICAXE 20X2 Microbot is a simple to assemble kit that uses a unique design which requires no soldering of wires to build and/or reconfigure a versatile robot. At the heart of the Microbot is a motherboard which contains a powerful PICAXE 20X2 microcontroller which can be programmed using flowcharts using the ‘Logicator for PICAXE’ software or in the PICAXE BASIC language. The Microbot can be programmed on Windows, Linux and Mac computer systems. Programs are downloaded via the AXE027 USB cable (purchase separately).

(c) Copyright Revolution Education Ltd. Web: www.picaxe.co.uk Version 1.3 06/11
Test of the Robot following the black line (opposite of what is done next : avoiding the black line)

The aim of this project was to gain a deep understanding of the basic principles of robotics, programming, and sensors (LED and Ultrasound).

The programme allowed the robot to detect any cone on the white platform it was placed on, and once detected to push them out of the platform. UltraSound sensors are used for this feature. Secondly, the robot had to autonomously move throughout the platform changing randomly direction and position in order to maximise the detection and find all the cones. Finally the last feature was to prevent the robot from falling off the platform when pushing the cones out. LED sensors located at the bottom of the robot are used in this case, detecting any black line, which were located at the edges of the platform. When black lines are detected the robot would turn turn around and change direction until there is no black line anymore.

Picaxe programming software
Picaxe programming software 2

Finally the inter-schools competition involved pushing the cones out of the platform as fast as possible, without the robot falling off the platform itself.

The Ultrasound Module is controlled by a single pin which both initiates an ultrasonic ‘ping’ and receives an echoed ‘pong’. The length of the returned pulse corresponds to the distance to the object. The millisecond pulse length value returned by the SRF005 command can be converted to centimetres by dividing by 58 and converted to inches by dividing by 148. As the base unit of the PICAXE-20X2 ‘pulsin’ command is actually 5ms, the pulsin value also needs to be multipled by 5 prior to dividing.

The two LED eyes of your Microbot are controlled by Output Pins B.1 and B.3 of the PICAXE-20X2. Note that the LED eyes will always briefly flash when the Microbot is first switched on or after it is reprogrammed. This is to indicate that the Microbot is working correctly. After the eyes flash the Microbot will then start running the program that is stored in it’s flash memory. The following flowchart will turn the left LED on for half a second, turn that LED off and turn the right LED on for half a second and repeat.

(c) Copyright Revolution Education Ltd. Web: www.picaxe.co.uk Version 1.3 06/11