External DAC vs Internal DAC

This is my experiment with DAC. First i am using external DAC. I am using PCF8591 I2C using STM32F103 and arduino framework. The result is terrible. It just got 10Hz with 100 resolutions. Unfortunately, i don’t have SPI DAC so i can’t test how fast it. Then i am trying to use internal DAC built in: STM32F103RET6 with stm32cube and same 100 resolutions. It’s reach 6KHz. Not bad.

Next time i’ll try to use DMA. It’s should be faster.