Birthday card that plays happy birthday tune and display greetings on a TFT display. The speaker is a piezo buzzer and the TFT is 0.96", 80x160 pixels, ST7735 driver, SPI interface. The name of the card receiver has to be changed in the code, the color of each letter can be set, name can be up to 6 letters, the letter number is the number of line in the "oled_font.c" file.
The circuit can be powered by 3-5V so one cell of lithium 3.7V can be used.

Birthday card that plays happy birthday tune and display greetings on a TFT display. The speaker is a piezo buzzer and the TFT is 0.96", 80x160 pixels, ST7735 driver, SPI interface. The name of the card receiver has to be changed in the code, the color of each letter can be set, name can be up to 6 letters, the letter number is the number of line in the "oled_font.c" file. Due to a software SPI the TFT is slow.
The circuit can be powered by 3-5V so one cell of lithium 3.7V can be used.

Birthday card that plays happy birthday tune and display greetings on a TFT display. The speaker is a piezo buzzer and the TFT is 0.96", 80x160 pixels, ST7735 driver, SPI interface. The name of the card receiver has to be changed in the code, the color of each letter can be set, name can be up to 6 letters, the letter number is the number of line in the "oled_font.c" file. File oled_font.c has to be in the same folder as the sketch.
ATtiny can be programmed using Arduino IDE and Arduino as ISP, see Technical Tips Burning bootloader with setting "Clock Source 8MHz internal", this makes the CPU working at frequency of 8MHz.
The ATtiny can be powered by 3-5V so one cell of lithium 3.7V can be used.

ATtiny13/13A generate repeated 'happy birthday to you' tune. The frequencies for the notes are suitable to drive piezo sounder.
The IC works down to 2 Volts so it can be powered by batteries.
The code and circuit can be used on ATtiny25/45/85 too.
ATtiny is programmed using Arduino IDE and Arduino as ISP. Use these instructions https://www.electronics-lab.com/project/how-to-program-attiny13attiny13a-using-arduino-ide/ with the setting : 4.8MHz, no millis no tone, LTO enabled.

Using PIC12F629 to generate repeated 'happy birthday to you' tune. The frequencies for the notes are suitable to drive piezo sounder.
The IC works down to 2 Volts so it can be powered by batteries.
Software includes PIC code C and ASM.