Page Flipper

Overview/Goal

The Page Flipper is an iPad stand that flips a page on command. A user will have their phone connected to the STM32L476RG board through BlueTooth. Then they can send commands to STM32 for flipping left or right. Their phone sends a signal to the STM32L476RG board through BlueTooth and UART, which controls a motor drive. The motor drive controls the motor for the Apple pen page-turner. The board will tell the motor driver how to control the step motors to flip to the next page/last page.

When we used the motor drive, the high current produced a huge amount of heat on the chip. We burnt a few motor drives during this project. So, we decided to add a temperature sensor to monitor the status of the motor drive. If the motor drive is overheating, the STM32 board will stop the motor.

Serial interface protocols

UART (Phone, BlueTooth)

I2C (Temperature Sensor)

Demo Video

Note: Unfortunately out step motor for this project malfunctioned in the process of building out the demo. The step motor needs to be squeezed by hand to reduce vibration to maintain a steady rotation without stuttering. So in the demo video, we demonstrated what the belt and pen system would look like if the motor were to function properly.

Weekly Updates

2.25 Update

• Read STM32 manual about motor control

  • TIM1 to generate PWM signals

  • SPI to configure controlled motors

• Search for alternative motor control solutions

  • Use STM32 motor control pack with setup software (https://www.st.com/en/applications/industrial-motor-control.html?sc=motorcontrol&ecmp=tt6272_us_social_dec2017)

  • Bipolar stepper motor or brushed motor is preferred in our project

• Order needed materials and peripherals

  • motor driver : L6208

• Joystick: Nunchuk (https://www.amazon.com/Wii-Nunchuk-Controller-White-nintendo/dp/B000IMYKQ0)

• Motor : Stepper motor: https://www.amazon.com/STEPPERONLINE-Stepper-Bipolar-Connector-compatible/dp/B00PNEQKC0/ref=sr_1_4?crid=385TB8ZMJY7ES&keywords=stepper+motor&qid=1645835282&sprefix=stepp%2Caps%2C162&sr=8-4

• 3D printer Belt: https://www.amazon.com/KeeYees-Timing-Tensioner-Torsion-Printer/dp/B07JKT5BZQ/ref=sr_1_3?crid=2TCIG9UINQK5A&keywords=3d+printer+belt&qid=1645835212&sprefix=3d+printer+belf%2Caps%2C147&sr=8-3

• Book holder frame: Lego(https://www.lego.com/en-us/page/static/pick-a-brick?page=1&filters.i0.key=variants.attributes.categoryId&filters.i0.values.i0=1&filters.i1.key=variants.attributes.subcategoryId&filters.i1.values.i0=1)

3.4 Update

• Ordered all planned peripherals except joystick

• replace L6208 with A4988

• added electrolyte capacitors and additional power source to support stepper motor

• started coding and configuring STM32 and A4988

• checked A4988 documentation

• plan for next week: finish coding, set up blue tooth module config, build book support frame with motor and rubber.

3.11 Update

• Ordered joystick

• Implemented the bluetooth UART with STM32

• Implemented joystick control

• built book hold frame with LEGO parts

• Not receiving step motor, progress behind

• Gonna catch up during the weekend and wrap up the project

3.16 Update

• Updated Block Diagram

• Uploaded Demo Video