I am having trouble understanding how to design a circuit that will transmit multiple analog data signals to a computer through one RS232 COM port.
The analog data is a simple voltage reading from 12 different LEDs. The LEDs are triggered by relays that are controlled with software from the same computer that I will use to monitor the LEDs. Other software will be developed to read which LEDs have been triggered and if they are operating within a specified voltage range. For now I am just trying to understand the hardware aspect of transferring 12 analog signals through a single COM port.
My understanding is that an analog multiplexer can be used to combine the voltage signals and transmit them to the computer's com port through a voltage converter/serial interface like the MAX232. Is this possible without using a microcontroller chip? If not, what chip should I use to perform this task? I am trying to avoid using a microprocessor in the interest of keeping things as simple as possible.
Ultimately, I am looking for the simplest way to transmit multiple analog signals through a single COM port on a PC. Thanks in advance.