makefile and spilib and tiltbuzz_3

adding the source for the final phase of this project.
we allow the addition of a pentiometer through an MCP3008 ADC
which we display the value of to the 1602 LCD.

project11/makefile

@@ -0,0 +1,14 @@
+
+clean: 
+	rm tiltbuzz_1 tiltbuzz_2 tiltbuzz_3
+
+all: tiltbuzz_1 tiltbuzz_2 tiltbuzz_3
+
+tiltbuzz_1: tiltbuzz_1.c lcd1602.c pinreadwrite.c
+	cc -o tiltbuzz_1 tiltbuzz_1.c lcd1602.c pinreadwrite.c -lwiringPi
+
+tiltbuzz_2: tiltbuzz_2.c lcd1602.c pinreadwrite.c
+	cc -o tiltbuzz_2 tiltbuzz_2.c  lcd1602.c pinreadwrite.c -lwiringPi
+
+tiltbuzz_3: tiltbuzz_3.c lcd1602.c spilib.c pinreadwrite.c
+	cc -o tiltbuzz_3 tiltbuzz_3.c  lcd1602.c spilib.c pinreadwrite.c -lwiringPi

project11/spilib.c

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+
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include <wiringPi.h>
+#include <wiringPiSPI.h>
+
+#include "spilib.h"
+
+static int spiFD;
+
+int spiAnalogRead(int spiChannel, int channelConfig, int analogChannel)
+{
+    if(analogChannel < 1 || analogChannel > 8)
+        return -1;
+
+    analogChannel--;
+
+    // from URL:
+    //   http://hertaville.com/interfacing-an-spi-adc-mcp3008-chip-to-the-raspberry-pi-using-c.html
+
+    // Raspberry Pi asserts the chip select signal connected to the MCP3008
+    // (CS0 in our case) by setting it to 0V. This is typically taken care
+    // of internally by the spidev driver whenever the proper ioctl() function is called.
+
+    // Raspberry Pi sends a byte containing a value of '1' to the MCP3008. This is a
+    // start bit. At the same time the MCP3008 sends back a 'don't care' byte to the Raspberry Pi.
+
+    // Raspberry Pi then sends a second byte whose most significant nibble
+    // (SGL/DIFF,D2,D1 & D0 bits) indicate the channel that we want to convert and
+    // whether we want single-ended or differential conversion (See Figure 5).
+    // For example if this nibble is "1000", the conversion will be single-ended
+    // and take place on channel 0 (CH0 pin). The least significant nibble is sent
+    // as 'don't care'. At the same time, the MCP3008 sends back the two most
+    // significant bits of the digital value (result) of the conversion (bits 8 and 9).
+
+    // Raspberry Pi sends another  'don't care' byte to the MCP3008. At the same time
+    // the MCP3008 send back a byte containing bits 7 through 0 0f the digital value
+    // (result) of the conversion.
+
+    // The Raspberry Pi then merges bits 8 & 9 from the second received byte with
+    // bits 7  through 0 from the third received byte to create the 10-bit digital
+    // value resulting from the conversion.
+
+    unsigned char buffer[3] = {1}; // start bit
+    buffer[1] = (channelConfig+analogChannel) << 4;
+
+    wiringPiSPIDataRW(spiChannel, buffer, 3);
+
+    return ( (buffer[1] & 3 ) << 8 ) + buffer[2]; // get last 10 bits
+}
+
+int spiClose (void)
+{
+
+    close (spiFD) ;
+}
+
+//    int spiChannel = 0;     // default is to use SPI channel 0 on the Raspberry Pi
+//    int channelConfig = CHAN_CONFIG_SINGLE;
+int spiOpen (int spiChannel, int channelConfig)
+{
+
+    spiFD = wiringPiSPISetup (spiChannel, 10000);
+    if (spiFD < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+

project11/spilib.h

@@ -0,0 +1,9 @@
+
+
+#define SPI_CHAN_CONFIG_SINGLE  8
+#define SPI_CHAN_CONFIG_DIFF    0
+
+int spiOpen (int spiChannel, int channelConfig);
+int spiClose (void);
+int spiAnalogRead(int spiChannel,int channelConfig,int analogChannel);
+

project11/tiltbuzz_3.c

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+
+#include <wiringPi.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "lcd1602.h"
+#include "spilib.h"
+#include "pinreadwrite.h"
+
+int main (int argc, char *argv[])
+{
+        // BUZZPIN is wiringPi Pin #1 or physical pin #12 or GPIO #18
+        int BUZZPIN = 1;
+	int LEDPIN = 3;
+	int SW520DPIN = 3;
+
+	if (wiringPiSetup() == -1) {
+		printf ("Setup wiringPi Failed!\n");
+		return -1;
+	}
+
+	lcd1602Open (0x27);
+	spiOpen (0, SPI_CHAN_CONFIG_SINGLE);
+
+	pinSetupWrite (BUZZPIN, LOW);
+	pinSetupWrite (LEDPIN, LOW);
+	pinSetupRead (SW520DPIN);
+
+	lcd1602Write (0, 0, "Welcome to tiltbuzz_2");
+	delay (2000);
+	lcd1602Clear();
+
+	int  iCount = 20;
+	for ( ; iCount > 0; iCount--) {
+		int  iDelay = ((iCount % 5) + 1) * 400;
+		char buffLines[2][24];
+
+		int iSpiVal = spiAnalogRead (0, SPI_CHAN_CONFIG_SINGLE, 2);
+
+		sprintf (buffLines[0], "tiltbuzz_2 %2d", iCount);
+		lcd1602Write (0, 0, buffLines[0]);
+		sprintf (buffLines[1], "Pent val %4d", iSpiVal);
+		lcd1602Write (0, 1, buffLines[1]);
+		pinWriteHiLo (BUZZPIN, 1, iDelay, iDelay);
+	}
+
+	// clean up the GPIO resources we have been using.
+	// make sure that things are back to a good state before exit.
+	pinCleanup (BUZZPIN);
+	lcd1602Close();
+	spiClose();
+
+	delay (500);
+	return 0;
+}