Problems getting an SSR to turn on
I have some bad news for you. Those SSRs have a "naked" infrared LED at the input. If you apply 3.3V or 5V on the input terminals without a current-limiting resistor, you'll more-than-likely destroy the SSR almost instantly. You should connect a series resistor to limit the current to something reasonable given the Vf of the LED. Something like 15mA or 20mA. 



Also, they're unsuitable for switching low voltage DC- they're designed to switch high voltage AC at the zero crossings. Probably they won't switch off once they've switched 'on' (depending on whether your LED current happens to exceed the holding current of the triac), or in the case of your circuit they will switch 'on' once only per SSR.