Alperen-Eroglu-Baykar-Challenge

Challenge 1

• By using Thread, the LEDs are made to blink at intervals of seconds as the "shutter_period_time" value in the config.json file.
• Added button interrupt and when the interrupt is triggered, timestamp value is taken and this value is saved in ts_buffer array.
• By using Thread, the values in ts_buffer are saved to the shutter.csv file at intervals of seconds (if a button interrupt occurred) as much as the "shutter_period_time" value in the config.json file.
• Added i2c_flag. The flag is set after timestamps are recorded in the shutter.csv file. If i2c_flag is set, "hello" message is sent to STM32F407VG card from i2c line and wakes Receive interrupt on STM32F407VG card. Then, 4 bytes of data are taken from the STM32F407VG card and the counter number is printed by collecting this data.

Cards Used

• Raspberry Pi 3B+
• STM32F407VG Disco

Pinouts of Raspberry Pi 3B+

• Led 1 (RED) = 7
• Led 2 (Green) = 0
• Button = 2
• I2C SDA = 3
• I2C SCL = 5

Mode of Leds --> Out Mode of Button --> In PUPD of Button --> Pull Up

Pinouts of STM32F407VG Disco

• PB10 --> I2C2_SCL
• PB11 --> I2C2_SDA

I2C2 is used for this project

Config.json

{"shutter_period_time":1}

System Images

Click here for the video of the system in operation

FlowChart of Raspberry Pi 3B+

graph  TD
    A[System Start]  -->B[Initialization]
    B  -->  C(Read shutter_period_time value in config.json)
    C  -->  T1[thread_shutter_pulse begin]
    C  -->  T2[thread_shutter_record begin]
    C  -->  INT[button_callback begin]
    C  -->  T3[thread_i2c begin]

    T1  -->  T11(Open LED1 and LED2)
    T11  -->  T1D1(Wait seconds at shutter_period_time)
    T1D1  -->  T12(Close LED1 and LED2)
    T12  -->  T1D2(Wait seconds at shutter_period_time)
    T1D2  -->  T11

    T2  -->  T2INT{Is it_occured value set?}
    T2INT  -->  |Yes| T2SAVE(Save values from ts_buffer array to shutter.csv)
    T2SAVE  -->  T2CLEAR(Clear it_occured flag and ts_buffer array)
    T2CLEAR  -->  T2SET(Set i2c_flag)
    T2SET  -->  T2D1(Wait seconds at shutter_period_time)
    T2D1  -->  T2INT
    T2INT  -->  |No| T2D2(Wait seconds at shutter_period_time)
    T2D2  -->  T2INT

    INT  -->  INT_ISPRESSED{Is button pressed?}
    INT_ISPRESSED  -->  |Yes| INT_ISPRESSED_Y(Save current timestamp value to ts_buffer array and print it with cout)
    INT_ISPRESSED_Y  -->  INT_ISPRESSED_1(set it_occured flag)
    INT_ISPRESSED_1  -->  INT_ISPRESSED
    INT_ISPRESSED  -->  |No| INT_ISPRESSED

    T3  -->  T3_INT{Is i2c_flag set?}
    T3_INT  -->  |Yes| T3_STM(Wake Receive Interrupt on STM32F407VG board)
    T3_STM  -->  T3_CNT(Sum the incoming data bytes and print the sum which is the counter value)
    T3_CNT  -->  T3_RST(Reset i2c_flag)
    T3_RST  -->  T3_INT
    T3_INT  -->  |No| T3_INT

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FlowChart of STM32F407VG Disco

graph TD
    A[System Start] -->B[Initialization]
    B --> C(Set 0 all bytes of i2c_veri)
    C --> D{Is receive interrupt occured?}
    D --> |No| D
    D --> |Yes| E(Send 4 byte i2c_veri)
    
    E --> CFB{Is first byte of i2c_veri less then 255?}
    CFB --> |Yes| FBI(Increase first byte of i2c_veri)
    FBI --> D
    CFB --> |No| CSB{Is first byte of i2c_veri equal 255 and second byte of i2c_veri less then 255?}
    
    CSB --> |Yes| SBI(Increase second byte of i2c_veri)
    SBI --> D
    CSB --> |No| CTB{Is second byte of i2c_veri equal 255 and third byte of i2c_veri less then 255?}
    
    CTB --> |Yes| TBI(Increase third byte of i2c_veri)
    TBI --> D
    CTB --> |No| CFFB{Is third byte of i2c_veri equal 255 and fourth byte of i2c_veri less then 255?}
    
    CFFB --> |Yes| FFBI(Increase fourth byte of i2c_veri)
    FFBI --> D
    CFFB --> |No| RST(Reset i2c_veri array)
    RST --> D

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Challenge 2

• Added 9 pin header for SD card connections from camera.
• Added SD card socket to save data from camera to SD card.
• Added GL827L integrated circuit and USB socket to transfer the data from the camera to the computer.
• 74LVC1G18 demultiplexers have been added to transfer the data from the camera to SD card or USB on demand.

74LVC1G18 Work Structure

A --> Camera Pins S --> MCU Selection 1Y --> SD Card 2Y --> SD Card Reader (USB)

As we can see from the table, if the selective value from the MCU pin is equal to 0, the data from the camera will be transferred to the SD card, if it is equal to 1, the data from the camera will be transferred to the USB.

Schematic

PCB

3D PCB