Hi All,I am newbie here, we have a hvac fan. it takes 0-10V dc input to control the speed. so far we have been using a variable power supply to control the speed. now we are thinking about building a digital controller.so far we found only one way to do it, using a dac and opamp. . something like this 0-10V DACthis one work over i2c but our PC only has rs232 and usb.is there a way we can build a 0-10V solution with rs232 interface or a i2c to rs232.Thanks
