WEBENCH® Tools: Amplitude Controlling of Sinewave from 0.4VAC to 6VAC at fixed Freq. 400Hz using MCU & POT

Hello,

MSP430FG438 has the 12-bit DAC module, you can use it to generate the signal wave that you want. You can find the DAC example code at below link for reference. This example code is using DAC12 outputs a 16 Step Ramp with 1 sample/sec. You need create a sine wave table with amplitude 2048 and bias 2048 and sample rate you want. Then using Timer to trigger DAC output update multiplying actual voltage amplitude at sample rate. But the DAC12 only can output positive voltage below reference. You need an external amplifier to generate a sine wave with +/-6V range.

http://dev.ti.com/tirex/#/?link=Software%2FMSP430Ware%2FDevices%2FMSP430F4XX%2FMSP430FG438%2FPeripheral%20Examples%2FRegister%20Level%2Ffet430_dac12_05.c

B.R

Winter