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48 lines
1.3 KiB
Arduino
48 lines
1.3 KiB
Arduino
2 years ago
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// MCP4922 Demo code sinewave at 16 res top to bot.
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// For comparison to MCP4725 operation (DAC_RESOLUTION=-5).
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#include <SPI.h>
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SPISettings settingsA(16000000, MSBFIRST, SPI_MODE0); // At 16 = SPI Clock = 8MHz.
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int RCLKPin = 53; // pin 12 on the 74hc595 latch - nSS
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int SRCLKPin = 52; // pin 11 on the 74hc595 shift register clock - SCK
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int SERPin = 51; // MOSI
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//////////////////////////////////////////////////////////////////////////////
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void setup() {
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Serial.begin(115200); // Start serial port (debug).
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pinMode(RCLKPin, OUTPUT); // Set SPI control PINs to output.
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pinMode(SRCLKPin, OUTPUT);
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pinMode(SERPin, OUTPUT);
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SPI.begin();
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Serial.println("MCP4922 SPI Dual DAC SPI hardware mode");
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noInterrupts();
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}
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//////////////////////////////////////////////////////////////////////////////
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// 0 - A, 1 - B
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//
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void writeMCP4922_AB(byte AB, uint16_t v) {
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v |=0xf000; // B15(A/B)=1 B, B14(BUF)=1 on, B13(GAn) 1=x1 B12(SHDNn) 1=off
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if (!AB) v &= ~0x8000; // When zero clear B15 for A.
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SPI.beginTransaction(settingsA);
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digitalWrite(RCLKPin, LOW);
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SPI.transfer( (0xff00 & v)>>8 );
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SPI.transfer( 0x00ff & v );
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digitalWrite(RCLKPin, HIGH);
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SPI.endTransaction;
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}
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void loop() {
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writeMCP4922_AB( 0, 4092 );
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writeMCP4922_AB( 1, 3000 );
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}
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