Hi everbody,
Ive managed to find an old SN76477 sound chip, that Id like to drive using my Arduino UNO.
After looking at he chip datasheet, I've realized that its pins must be connected to variable resistors and capacitors.
Is it possible to use the Arduino to "simulate" variable resistors and capacitors in order to drive the sound chip?
Thanks in
advance for your help.
No not directly.
However you can use a digital pot to simulate variable resistors.
Capacitors are a bit more tricky but you can use an 4051 analog switch, to switch in various values of capacitor onto a line.
Digital variable potentiometers do exist - so the resistor side of things is there; for a digital variable capacitor - check out these two links:
http://www.afrotechmods.com/cheap/capacitor/digitalcapacitor.htm
Note that for the second one, I am not sure how well that would work - but it or something like it should be possible. What you're likely to run into though with a standard Arduino (ie, an UNO) is not having enough output pins (for the variable caps, variable resistors, and digital outputs for those inputs on the SN76477). You might need to use an SPI digital i/o expander chip, or some shift registers, to get the necessary number (or go with a Mega - even there, though, you may or may not have enough pins available).
The first link is a varicap replacement and doesn't have enough capacitance change for the OP. The second needs open collector outputs which are not directly available on the arduino.
I also have an old SN76477 in a drawer, waiting for an hypothetical future use.
Unfortunately, this is mostly an analogic chip, except for the 3 digital pins to select the mixer output.