I'm new to the Pi and have only limited soldering and electronics experience from the ancient past- but know how to use google
I'm planning to use my Pi for reading several power meters at my home- either older Ferraris types or ones with blinking LEDs (1000 impulse per kWh).
For the latter I'm thinking of hooking up a simple photo diode plus pullup resistor to an GPIO input. Is that all it takes or do I need an op amp? Or would a photo transistor be better suited (thinking about the transistor for the Ferraris type meter anyway...)