This is the forth instalment in a series of blog posts to support a RoadTest Review of the ACCESS:bit for micro:bit . The review is being conducted by a student from a high school computer club. Details on how the RoadTest is being conducted can be found here RoadTest Support: ACCESS:bit for micro:bit The Application

 

The objective for this week was to program the ACCESS:bit and have the barrier move. The student was not successful in achieving that objective. The barrier does not move when code is run.

 

It was noted in theRoadTest Support: ACCESS:bit for micro:bit Initial Impressions that the documentation provided from the ACCESS:bit RoadTest Review didn't reflect the device delivered. It was also discovered the code provided in the documentation is not the code currently supported from the GitHub resource link provided.

Difference in physical hardware (note: left and right servo not supported & speaker mounting changed)

 

Difference in code blocks available for programming. Blocks on left are not available.

 

The confusion created by the poor documentation contributed to the student not getting the ACCESS:bit working. The instructions for what the student needed to do to move the ACCESS:Bit barrier were not clear. It was encouraging to see the student started to troubleshoot the issue without the need for guidance.


At a regular scheduled Google Hangout meeting with the Coach the following was reviewed.

  • Assembly confirmed.
  • Servo physical connection pin out confirmed. (servo can be connected backwards, no keying to prevent this)
  • Servo confirmed working on Arduino. (servo test circuit on Arduino confirm servo operation)
  • Reviewed how the Micro:bit is programmed. (Action item: Need more documentation)
  • Confirm coding practice correct: Successfully ran program to have ACCESS:bit buzzer sound.
  • Install ACCESS:bit batteries and test operation (Action item: install battery & test)
  • Test Servo on Micro:bit directly. (Action item: direct connect servo and test)

 

Using the resources of makecode.microbit.org and the ACCESS:bit resources provided through GitHub, a schematic (left) of the servo circuit is displayed when the code is saved.

The schematic is being used as a troubleshooting aid. It doesn't appear to represent the actual configuration of the device. The schematic (left)doesn't show a battery or a switch that are on the ACCESS:bit (right). The device also has a integrated circuit labeled Reg1. The assumption is the battery, switch and circuit are used to operate the servo. The schematic (left) suggests servo motor can be tested without the ACCESS:bit. The focus is to get the device working. Testing the servo without the ACCESS:bit connected is a follow-up test after trying the unit with batteries.

 

The student demonstrated how the micro:bit was programmed. There was some difficultly in explaining how they developed the knowledge learning curve. The documentation to complete the task is not clear. The student has been tasked with documenting, How they uncovered the resources they needed in order to program the device.

 

The student will continue to work independently from the Coach to complete the task of getting the ACCESS:bit working, along with documenting their learning. A Milestone meeting has been schedule to provide the student time to work the problem but also the break point to give assistance in order to avoid struggling.