资 源 简 介
This application note describes the interface between an HC705J1A anda multiplying digital-to-analog converter (MDAC) to digitally control theamplification or attenuation of an operational amplifier circuit. The MDACused is Analog Device’s DAC8043, a 12-bit, 8-pin serial device. By usingthe MDAC, a mechanical potentiometer can be replaced by a morereliable and robust solution.The microcontroller unit (MCU) interface must be able to “talk” to theDAC8043 using a serial communication link. The serial peripheralinterface (SPI) is one of the most widely used serial transmissionmethods for communication between an MCU and a peripheral,although not all HC05 Family members have SPI modules. An HC05MCU without an SPI must interface with the DAC8043 using a softwareinput/output (I/O) driver. This method uses software bit programming tocommunicate with the DAC8043. Even though it is not as efficient as thehardware SPI method, it provides the MCU with a means to send datato the DAC8043.
