ML1 and QTR1A are same sensors with different PCB design and giving analog output depending on colour. QTR1RC is digital sensor that can work with measuring RC time contast depending on surface colour.

We strongly suggest to use ML1 or QTR1A sensor with your mcu's digital pins. Yes these sensors giving analog output but at white/black full contrast they directly give as 0V - 5V digital output.

In some circumstances you can attach these QTR1A or ML1 sensors to analog input of MCU and you can use comparing with some threshold. We do like that at light places that can affect sensor's output.