*Creating a Bit-Banged Library for an OLED Display with the CH32 Microcontroller* * *0:00** Introduction:* The video continues the CH32 tutorial series, focusing on creating a custom library for an OLED display using a bit-banging approach. * *1:17** Display:* The specific OLED display used is a 72x40 pixel display. * *1:24** External Resources:* Two primary resources are used: the SSD1306 display driver datasheet (for 128x64 displays but applicable) and the specific datasheet for the 72x40 pixel display. * *2:56** Implementation:* The code implementation is based on the pseudo-code provided in the 72x40 display's datasheet. * *3:42** Bit Banging:* The technique involves manually controlling the I2C bus (SDA and SCL pins) bit by bit instead of using built-in I2C libraries. * *4:16** Pin Definition:* The same pins used for standard I2C communication (PC1 for SDA, PC2 for SCL) are redefined as general-purpose input/output (GPIO) pins. * *6:14** Open Drain Configuration:* The SDA pin (PC1) is configured as an open-drain output, while the SCL pin (PC2) is a push-pull output. * *6:48** Bit-Banged I2C Function:* A custom function `i2c_bitbang` is implemented to send data bit by bit to the display, following the timing diagrams in the datasheet. * *10:49** Start, Stop, and Acknowledge:* Functions `i2c_start`, `i2c_stop`, and `i2c_ack` are created to manage the I2C communication protocol, including start and stop conditions and acknowledgments. * *13:31** Write Command and Data:* Functions `i2c_write_command` and `i2c_write_data` are implemented to send commands and data to the display, respectively. These functions use the `i2c_bitbang` function for the actual bit manipulation. * *16:12** Initialization:* An `init_oled` function is created to initialize the display, following the initialization sequence in the SSD1306 datasheet. This involves sending a series of commands to set display parameters like contrast, display on/off, etc. * *22:56** Erasing the Display:* A function `oled_erase` is implemented to clear the display by writing zeros to all segments. This involves iterating through each page and segment of the display. * *23:20** Display Structure:* The display is organized into five pages (0-4), each with 72 segments. Each segment represents 8 pixels vertically. * *27:24** ASCII Table:* The ASCII table is used to map character codes to their visual representations on the display. * *28:47** Character Representation:* Each character is represented by 5 bytes, corresponding to 5 segments on the display. Each byte defines the 8 pixels within a segment. * *34:33** Font Matrix:* A large matrix stores the 5-byte representations for each character. The matrix is indexed based on the ASCII value of the character minus 0x20. * *35:43** Printing a Character:* The `print_char` function takes the page, segment, and character as input. It uses the font matrix to determine the 5 bytes for the given character and sends them to the display. * *43:13** Printing Text:* The `print_text` function takes a string as input and prints it to the display. It handles line breaks and ensures that text wraps to the next line if it exceeds the display width. * *43:19** Using USART Interrupt:* The code is modified to receive text via USART interrupt. A buffer is used to store the received characters, and a flag indicates when a complete line of text has been received. * *51:43** Text Handling in Main Loop:* In the main loop, the code checks for the USART flag and, when set, prints the received text to the display and then clears the buffer. * *56:36** Character Positioning:* The code calculates the position of each character on the display, ensuring that characters are printed sequentially and wrap to the next line when necessary. * *1:02:48** Conclusion:* The video demonstrates how to create a custom bit-banged library for controlling an OLED display with the CH32 microcontroller, including initializing the display, erasing, printing characters, and handling text input via USART. * *1:03:08** Website Resources:* The presenter mentions that additional resources, including code examples and product links, are available on their website. I used gemini-1.5-pro-exp-0827 on rocketrecap dot com to summarize the transcript. Cost (if I didn't use the free tier): $0.04 Input tokens: 25465 Output tokens: 1068
*Creating a Bit-Banged Library for an OLED Display with the CH32 Microcontroller*
* *0:00** Introduction:* The video continues the CH32 tutorial series, focusing on creating a custom library for an OLED display using a bit-banging approach.
* *1:17** Display:* The specific OLED display used is a 72x40 pixel display.
* *1:24** External Resources:* Two primary resources are used: the SSD1306 display driver datasheet (for 128x64 displays but applicable) and the specific datasheet for the 72x40 pixel display.
* *2:56** Implementation:* The code implementation is based on the pseudo-code provided in the 72x40 display's datasheet.
* *3:42** Bit Banging:* The technique involves manually controlling the I2C bus (SDA and SCL pins) bit by bit instead of using built-in I2C libraries.
* *4:16** Pin Definition:* The same pins used for standard I2C communication (PC1 for SDA, PC2 for SCL) are redefined as general-purpose input/output (GPIO) pins.
* *6:14** Open Drain Configuration:* The SDA pin (PC1) is configured as an open-drain output, while the SCL pin (PC2) is a push-pull output.
* *6:48** Bit-Banged I2C Function:* A custom function `i2c_bitbang` is implemented to send data bit by bit to the display, following the timing diagrams in the datasheet.
* *10:49** Start, Stop, and Acknowledge:* Functions `i2c_start`, `i2c_stop`, and `i2c_ack` are created to manage the I2C communication protocol, including start and stop conditions and acknowledgments.
* *13:31** Write Command and Data:* Functions `i2c_write_command` and `i2c_write_data` are implemented to send commands and data to the display, respectively. These functions use the `i2c_bitbang` function for the actual bit manipulation.
* *16:12** Initialization:* An `init_oled` function is created to initialize the display, following the initialization sequence in the SSD1306 datasheet. This involves sending a series of commands to set display parameters like contrast, display on/off, etc.
* *22:56** Erasing the Display:* A function `oled_erase` is implemented to clear the display by writing zeros to all segments. This involves iterating through each page and segment of the display.
* *23:20** Display Structure:* The display is organized into five pages (0-4), each with 72 segments. Each segment represents 8 pixels vertically.
* *27:24** ASCII Table:* The ASCII table is used to map character codes to their visual representations on the display.
* *28:47** Character Representation:* Each character is represented by 5 bytes, corresponding to 5 segments on the display. Each byte defines the 8 pixels within a segment.
* *34:33** Font Matrix:* A large matrix stores the 5-byte representations for each character. The matrix is indexed based on the ASCII value of the character minus 0x20.
* *35:43** Printing a Character:* The `print_char` function takes the page, segment, and character as input. It uses the font matrix to determine the 5 bytes for the given character and sends them to the display.
* *43:13** Printing Text:* The `print_text` function takes a string as input and prints it to the display. It handles line breaks and ensures that text wraps to the next line if it exceeds the display width.
* *43:19** Using USART Interrupt:* The code is modified to receive text via USART interrupt. A buffer is used to store the received characters, and a flag indicates when a complete line of text has been received.
* *51:43** Text Handling in Main Loop:* In the main loop, the code checks for the USART flag and, when set, prints the received text to the display and then clears the buffer.
* *56:36** Character Positioning:* The code calculates the position of each character on the display, ensuring that characters are printed sequentially and wrap to the next line when necessary.
* *1:02:48** Conclusion:* The video demonstrates how to create a custom bit-banged library for controlling an OLED display with the CH32 microcontroller, including initializing the display, erasing, printing characters, and handling text input via USART.
* *1:03:08** Website Resources:* The presenter mentions that additional resources, including code examples and product links, are available on their website.
I used gemini-1.5-pro-exp-0827 on rocketrecap dot com to summarize the transcript.
Cost (if I didn't use the free tier): $0.04
Input tokens: 25465
Output tokens: 1068