Review on KNACRO PCF8591 AD/DA Converter Module: Efficient Analog to Digital Conversion by Shawn Pollock

Works very well but not as described. The board layout is slightly different and although the description says "3 hardware address pins" the address 0x48 is soldered on this board and cannot be changed. The board comes with a light sensor, a temperature sensor and a manual potentiometer. There are jumpers on the board to connect each of them to one of the 4 available inputs. When delivered, AIN0 is a pot, AIN1 is a light sensor and AIN2 is a temperature sensor. ). For example, a return value of 128 using 5 volts means that 2.5 volts were measured. This also applies to built-in sensors, so some calibration is required to convert them to temperature or light level to lux. There are 2 red LEDs on the board, one is on when the board is powered, the other is on when the analog output is on. The chip appears to be storing the value in a buffer. So to get the current value of an output, you need to call read twice. For some reason the maximum output voltage is 4.12V with a supply voltage of 5V. This is by design, if you look at the datasheet for the PCF8591 it shows the maximum power under VDD and mentions that the voltage varies with the load resistance. The AIN pins measure AOUT correctly, so you can reserve a pin to measure the actual output.