Circuit Biscuits

Lesson 7 - Wireless Control With HC05 And Android Pupil Notes

The HC-05 adds wireless control by presenting a serial-style link to the microcontroller. We compare controlling the board from the browser dashboard and from the Android app.

In This Lesson

Lesson 7 Pupil Notes

Title

Wireless Control With HC-05 And Android

Big Question

How can the same board be controlled without a USB cable running all the way to the dashboard?

What This Lesson Is About

The HC-05 adds wireless control by presenting a serial-style link to the microcontroller. We compare controlling the board from the browser dashboard and from the Android app.

Key Words

  • Bluetooth
  • wireless
  • UART
  • app
  • pairing
  • serial

Before You Start

  • Check that the HC-05 module is connected.
  • Make sure Bluetooth is enabled on the phone.
  • Be ready to compare wired and wireless control.

What To Remember

  • Bluetooth can replace a short cable for control
  • the Android app is another front end for the same firmware
  • the HC-05 still looks like a UART-style serial link to the microcontroller
  • changing the user interface does not always require changing the whole firmware design

What We Did

  • connected with the Android app
  • sent commands wirelessly
  • compared wired and wireless control
  • discussed how the same firmware can support different interfaces

What To Look For

  • what feels different between browser and phone control?
  • what stays the same?
  • where do you still see the same command-and-response idea?

Try This

  • Connect over Bluetooth.
  • Change a mode or set some text.
  • Compare the response with the same action over USB or the browser.

Why It Matters

Real embedded products often support more than one control interface. This lesson shows how a system can stay logically consistent even when the front end changes.

Check Yourself

  • What does the HC-05 add to the system?
  • Why is UART still relevant in a wireless lesson?
  • What is similar between the Android app and the web dashboard?
  • What is different?

Reflection

  • One thing that felt easier wirelessly:
  • One thing that felt harder wirelessly:
  • One reason a product might offer both wired and wireless control: