Is it possible to connect multiple light sensors to one port and similiarly control multiple motors through one port only?
(I've tried searching for answers on Google, couldn't find a convincing answer anywhere)
Any help, redirection to literatures, tutorials, answer is appreciated.
Thanks.
You can use a MCP3008 chip to read up to 8 analog sensors via the 4 SPI pins. Have a look at this diagram on upverter.
You can also look at my corresponding python code to read the sensors here..
This shows how to read the analog photo sensors over spi using WebIOPi as well as control a stepper motor.
The short answer: no. A GPIO port is a collection of pins. I assume you mean a single pin.
A pin can only take one input or output one value. So you could connect multiple LEDs in series to one pin, but you couldn't connect multiple light sensors to one pin.
The GPIO on the Raspberry Pi can't take analog input like that from an LDR (Light Dependent Resistor). You need an external ADC (Analogue-to-Digital Converter). Often these will include more than one input, so you can connect multiple LDRs or potentiometers.
Recent Pis have 21 usable gpios. 17 on P1 and 4 on P5.
Generally you need
The number of gpios needed per sensor depends on the sensor.
You can use use multiple devices on the I2C buses (the Pi has 2, each of 2 gpios). All sorts of sensors support I2C.
The Pi has no analogoue gpios so you can't connect sensors with analogue outputs to a Pi gpio.
