Hello,
I'm planning a project to have a vintage computer(a TI-99 in this case) control an RC car. So far I've worked out that the best way to do this with the computer I have on hand is to use its "CALL SOUND" command, which can generate a 44 to 44,000Hz signal for a minimum of one millisecond. I have a friend who is more familiar with Arduino programming, while I'm handling the BASIC and hardware side of the project. My questions are, can an Arduino chip translate these frequencies into command(it'll have a direct connection to the computer's sound output) and what kind of hardware would I need for it to transmit to an RC car?
Does the TI-99 have a serial port? You would only need a MAX232 to translate RS-232 to TTL serial for a software serial port on the Arduino (and use the hardware port for programming and troubleshooting).
It has an expansion port, but to utilize it requires Assembly language and another piece hardware. So I would rather use BASIC and just use the audio out.
Thought I'd ask. Take a look at the pulseIn() function (in the language reference). With pulseIn() you can measure, with microsecond resolution, pulse widths and have different widths mean different commands.
Excellent, now what kind of hardware for the Arduino side am I looking for?
What voltage is the sound card output? If the sound card signal is 0 to 5V (or even down to 3V) you can feed it to a digital input. I would put a 1K resistor in series to add a bit of protection to the input.
I'll check on that tomorrow, I'm picking up the computer tomorrow. The sound signal is coming from the computer DIN-5 connector that hooks into either a monitor or RF modulator.
Alright, I checked it and the voltage is under 5V. So what kind of Arudino chip do I need for this?
The signal needs to be 0 to 5V. You also need to make sure that the signal does not go below 0V (negative). You ask which chip will work. Do you mean Arduino board or bare chip? I use the UNO R3 with Mega328 DIP because I can replace the 328 if something goes wrong (and it has).
I'm new to Arduino, I can make my own boards though.
So you're saying, use this board? http://www.amazon.com/Arduino-UNO-board-DIP-ATmega328P/dp/B006H06TVG
I found this project, I I think it can easily be applied to this project. All I need to do is make it accept the computer's sound signals.
Yes, that is the board. And a great price, too. To add a bit of protection to the digital input that you connect the signal to, add a 1K resistor in series between the signal and input pin.