MSP430F5438 ADC12 learning some points

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MSP430F5438 ADC12 learning some points [Copy link]

Some points to note 1. Increase the sampling time. If conditions permit, increase the sampling time as much as possible, so that the conversion result can be more stable. 2. MSP430F5438 does not have a REF module. The sample code or data sheet reference manual that can be downloaded from the TI official website are all centered on the MSP430F5438A. However, many MCUs on the market are still MSP430F5438. In fact, there is a difference between MSP430F5438A and MSP4305438. MSP430F5438 does not have a REF module, so using the on-chip 2.5 reference power supply is still unstable. You can test it through the following implementation. The target of AD conversion is still LDO output. The following parts of the code need to be modified. First: ADC12CTL0 = ADC12SHT0_15 + ADC12SHT1_15 + ADC12ON; Modify to ADC12CTL0 = ADC12SHT0_15 + ADC12SHT1_15 + ADC12ON + ADC12REF2_5V + ADC12REFON; Use to open the on-chip 2.5V reference power supply. Second: ADC12MCTL0 = ADC12SREF_0 + ADC12INCH_11; Modify to ADC12MCTL0 = ADC12SREF_1 + ADC12INCH_11; Convert the reference voltage to Vref, that is, modify the 2.5V reference power supply set in 1. Third: float ldo_voltage = ADC12MEM0 / 4096.0 * 3.3 * 2; Modify to float ldo_voltage = ADC12MEM0 / 4096.0 * 2.5 * 2; Replace the conversion formula, the reference voltage changes from 3.3V to 2.5V