I want to drive this SSR from a digital out: Digikey 425-2403-5-ND
The datasheet is here [https://media.digikey.com/pdf/Data%20Sheets/Sharp%20PDFs/S102,202S02.pdf]
I don't understand how to properly size the needed resistor between the output and the SSR.
The arduino "DigitalPins" wiki (https://www.arduino.cc/en/Tutorial/DigitalPins) gives a baseline of "470 to 1K" ohms on a digital out pin.
On the SSR datasheet, page 4, it lists a 20mA draw at 1.2V. I calculate R = (5-1.2)/20 = 190 ohms.
On the SSR datasheet, page 6, fig 4, I interpolate a 110mA draw at 1.2V. I calculate R = (5-1.2)/110 = 35 ohms.
Not only are these two values different, they are quite low compared to the baseline.
I'd appreciate any help figuring this out. Thanks in advance.