I am working with a BeagleBoard running Linux 3.0.63, and I am trying to get the I2C and I2S interfaces to work, with the end goal of playing a .wav file on the beagleboard and having the I2C and I2S set up correctly.
I am currently stuck on setting the BeagleBoard to be the master clock for the I2S line. Or the slave clock could also work. In any case, I have no idea where the I2S stuff is set in the kernel code. I assumed in arch/arm/mach-omap3/board-omap3beagle.c, but I cannot find it.
Btw, is there hidden documentation on how to do this that I do not know about?
Have a look at files sound/soc/omap/omap3beagle.c and include/sound/soc-dai.h:
First one has a function:
static int omap3beagle_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
/* couple of lines */
switch (params_channels(params)) {
case 2: /* Stereo I2S mode */
fmt = SND_SOC_DAIFMT_I2S |
SND_SOC_DAIFMT_NB_NF |
SND_SOC_DAIFMT_CBM_CFM;
break;
case 4: /* Four channel TDM mode */
fmt = SND_SOC_DAIFMT_DSP_A |
SND_SOC_DAIFMT_IB_NF |
SND_SOC_DAIFMT_CBM_CFM;
break;
default:
return -EINVAL;
}
/* some stuff */
}
And the second one has macro-definitions:
/*
* DAI hardware clock masters.
*
* This is wrt the codec, the inverse is true for the interface
* i.e. if the codec is clk and FRM master then the interface is
* clk and frame slave.
*/
#define SND_SOC_DAIFMT_CBM_CFM (1 << 12) /* codec clk & FRM master */
#define SND_SOC_DAIFMT_CBS_CFM (2 << 12) /* codec clk slave & FRM master */
#define SND_SOC_DAIFMT_CBM_CFS (3 << 12) /* codec clk master & frame slave */
#define SND_SOC_DAIFMT_CBS_CFS (4 << 12) /* codec clk & FRM slave */
So using them you can adjust I2S clocking for "Stereo I2S mode" as you need.
There are a lot of other options but I guess these ones are the exactly what you need.
Some documentation can be found at Documentation/sound/alsa/soc.
Related
I am having a lot of trouble when it comes to flash erasing on the dsPIC33EP64GP503 and I am hoping someone on here will be able help.
I am wanting to store a data struct in the flash program memory of the device. I am having trouble when it comes to erasing the flash though. I need to erase it and re-write it when the data changes.
I am padding the rest of the page with 0s so it can be safely erased.
I can write to the same memory location of the struct. When doing a flash write onto the start of the struct, the byStructValid turns into 0x11 (I know this is all very bad, because it is writing double word. But I am just trying to get the flash operations working first), however when I do an erase nothing happens. Is someone able to figure out what I am doing wrong?
I initialised the struct with 0xFF's and tried to perform a flash write. This was successful as the CAN message I received showed the data changed from 0xFF to 0x11.
I then tried to do a flash erase, but nothing happened. The device just carried on as normal. I don't have access to debug so it is hard to fully understand what is going on during this time.
I have tried moving the struct location around, so that it is on an 'even' page boundary (as specified in the datasheet) but this hasn't worked either.
I have also tried using an assembly version of the erase function, provided by the datasheet, this also doesn't work. The device just carries on as though there was no command for flash erase.
Below are some snippets of code that I have been using.
Any help would be greatly appreciated, thank you.
Note: I am unable to use the debugger. I use CAN messages to periodically send ‘debug’ messages, which contain data that is read from the flash location. This is so I can see if the write/erases are working.
#define MEMORY_USER_CALIBRATION_LOC 0x006000
typedef struct
{
byte byStructValid;
byte abyStructData[3];
}stFlashStruct_t;
volatile const __prog__ stFlashStruct_t stFlashStruct __attribute__((space(prog), address(MEMORY_USER_CALIBRATION_LOC))) =
{
.byStructValid = 0xFF,
.abyStructData = {50, 10, 20},
};
const byte padding[_FLASH_PAGE*2 - sizeof(stFlashStruct_t)] __attribute__((space(prog), address(MEMORY_USER_CALIBRATION_LOC + sizeof(stFlashStruct_t)))) = {0};
//FLASH Write
void FLASH_WriteDoubleWord(dword address, dword data[2])
{
word INTCON2Save;
word i;
//set WREN and ERASE settings for operation
NVMCON = 0x4001;
TBLPAG = 0xFA;
//set address to erase
NVMADR = address & 0xFFFF;
NVMADRU = (address >> 16) & 0x3F;
for (i = 0; i < 2; i++)
{
__builtin_tblwtl(i*2, data[i] & 0xFFFF);
__builtin_tblwth(i*2, (data[i] >> 16) & 0xFF);
}
//save the interrupt register
INTCON2Save = INTCON2;
// Disable interrupts for NVM unlock
__builtin_disable_interrupts();
__builtin_write_NVM();
// Start write cycle
while(NVMCONbits.WR == 1);
//restore interrupts
INTCON2 = INTCON2Save;
}
//FLASH Erase
void FLASH_ErasePageC(dword dwAddress)
{
word INTCON2Save;
//set WREN and ERASE settings for operation
NVMCON = 0x4003;
//set address to erase
NVMADRU = (dwAddress >> 16) & 0x3F;
NVMADR = dwAddress & 0xFFFF;
//save the interrupt register
INTCON2Save = INTCON2;
__builtin_disable_interrupts();
// Disable interrupts for NVM unlock
__builtin_write_NVM();
// Start write cycle
while(NVMCONbits.WR == 1);
//restore interrupts
INTCON2 = INTCON2Save;
}
byte temp_flash_write(void)
{
dword new_data[2] = {0x1111, 0x1111};
FLASH_WriteDoubleWord(&stCustomerCalibration, new_data);
return 0;
}
Your "dsPIC33 Flash Erase broken" issue is one of not understanding just how badly the Run Time Flash Programming (RTFP) method is described in the Microchip dsPIC33EP64GP503 data sheet and family reference manuals.
This post will not explain how any of this works. It does work but is really hard to comprehend.
What will be hard for you is that a program flash word can only be written one time after an erase. Writing to the same program flash word a second time will corrupt it and the next time it is read an ECC trap error will assert.
Attached is example code that allocates a 1024 instruction word page at address 0x6000. Declares a structure at the start of that page that is 2 instruction words in size. The code then erases that page then writes different data to the first 2 instruction words in that page.
/*
* File: main.c
* Author: Dan1138
*
* Description:
* Example for Run Time Self Programming (RTSP).
* This is very limited, useful as a test bench but not much more.
*
* Created on December 10, 2022, 2:05 PM
*/
/* Define the system oscillator frequency this code must configure */
#define FSYS (7372800ul)
#define FCY (FSYS/2ul)
// DSPIC33EP64GP503 Configuration Bit Settings
// 'C' source line config statements
// FICD
#pragma config ICS = PGD1 // ICD Communication Channel Select bits (Communicate on PGEC1 and PGED1)
#pragma config JTAGEN = OFF // JTAG Enable bit (JTAG is disabled)
// FPOR
#pragma config ALTI2C1 = OFF // Alternate I2C1 pins (I2C1 mapped to SDA1/SCL1 pins)
#pragma config ALTI2C2 = OFF // Alternate I2C2 pins (I2C2 mapped to SDA2/SCL2 pins)
#pragma config WDTWIN = WIN25 // Watchdog Window Select bits (WDT Window is 25% of WDT period)
// FWDT
#pragma config WDTPOST = PS32768 // Watchdog Timer Postscaler bits (1:32,768)
#pragma config WDTPRE = PR128 // Watchdog Timer Prescaler bit (1:128)
#pragma config PLLKEN = ON // PLL Lock Enable bit (Clock switch to PLL source will wait until the PLL lock signal is valid.)
#pragma config WINDIS = OFF // Watchdog Timer Window Enable bit (Watchdog Timer in Non-Window mode)
#pragma config FWDTEN = OFF // Watchdog Timer Enable bit (Watchdog timer enabled/disabled by user software)
// FOSC
#pragma config POSCMD = NONE // Primary Oscillator Mode Select bits (Primary Oscillator disabled)
#pragma config OSCIOFNC = ON // OSC2 Pin Function bit (OSC2 is general purpose digital I/O pin)
#pragma config IOL1WAY = OFF // Peripheral pin select configuration (Allow multiple reconfigurations)
#pragma config FCKSM = CSECMD // Clock Switching Mode bits (Clock switching is enabled,Fail-safe Clock Monitor is disabled)
// FOSCSEL
#pragma config FNOSC = FRC // Oscillator Source Selection (Internal Fast RC (FRC))
#pragma config IESO = ON // Two-speed Oscillator Start-up Enable bit (Start up device with FRC, then switch to user-selected oscillator source)
// FGS
#pragma config GWRP = OFF // General Segment Write-Protect bit (General Segment may be written)
#pragma config GCP = OFF // General Segment Code-Protect bit (General Segment Code protect is Disabled)
// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.
#include <xc.h>
#include <libpic30.h>
#define MEMORY_USER_CALIBRATION_LOC (_FLASH_PAGE * 24)
typedef struct
{
uint8_t byStructValid;
uint8_t abyStructData[3];
} stFlashStruct_t;
volatile const __prog__ __attribute__((space(prog), address(MEMORY_USER_CALIBRATION_LOC))) union
{
uint16_t words[_FLASH_PAGE]; /* reserve the entire erase page. Note only the low 16-bits of the instruction word can be accessed with this method. */
struct {
stFlashStruct_t stFlashStruct; /* calibration structure */
};
} CalSpace =
{
.stFlashStruct.byStructValid = 0xFF,
.stFlashStruct.abyStructData = {50, 10, 20},
};
int main(void)
{
volatile stFlashStruct_t ReadBack;
/*
* application initialization
*/
ReadBack.byStructValid = CalSpace.stFlashStruct.byStructValid;
ReadBack.abyStructData[0] = CalSpace.stFlashStruct.abyStructData[0];
ReadBack.abyStructData[1] = CalSpace.stFlashStruct.abyStructData[1];
ReadBack.abyStructData[2] = CalSpace.stFlashStruct.abyStructData[2];
__builtin_software_breakpoint(); /* breakpoint here to inspect the ReadBack structure with the debugger */
Nop();
Nop();
/* Erase 1024 instruction words starting at address MEMORY_USER_CALIBRATION_LOC */
NVMCON = 0x4003;
NVMADR = __builtin_tbloffset(&CalSpace);
NVMADRU = __builtin_tblpage(&CalSpace);
__builtin_disi(5); // Disable interrupts for NVM unlock
__builtin_write_NVM(); // Start write cycle
while(NVMCONbits.WR == 1);
ReadBack.byStructValid = CalSpace.stFlashStruct.byStructValid;
ReadBack.abyStructData[0] = CalSpace.stFlashStruct.abyStructData[0];
ReadBack.abyStructData[1] = CalSpace.stFlashStruct.abyStructData[1];
ReadBack.abyStructData[2] = CalSpace.stFlashStruct.abyStructData[2];
__builtin_software_breakpoint(); /* breakpoint here to inspect the ReadBack structure with the debugger */
Nop();
Nop();
/* Update data in structure to be written */
ReadBack.byStructValid = 1;
ReadBack.abyStructData[0] = 2;
ReadBack.abyStructData[1] = 3;
ReadBack.abyStructData[2] = 4;
/* Write 2 instruction words starting at address MEMORY_USER_CALIBRATION_LOC */
NVMCON = 0x4001; // Set WREN and word program mode
TBLPAG = 0xFA; // write latch upper address
NVMADR = __builtin_tbloffset(&CalSpace.stFlashStruct);
NVMADRU = __builtin_tblpage(&CalSpace);
__builtin_tblwtl(0,*((uint16_t *)(&ReadBack)+0)); // load low 16-bits of first instruction word
__builtin_tblwth(0,0x00); // make high 8-bits of first instruction word zero
__builtin_tblwtl(2,*((uint16_t *)(&ReadBack)+1)); // load low 16-bits of second instruction word
__builtin_tblwth(2,0x00); // make high 8-bits of second instruction word zero
__builtin_disi(5); // Disable interrupts for NVM unlock sequence
__builtin_write_NVM(); // initiate write
while(NVMCONbits.WR == 1);
ReadBack.byStructValid = CalSpace.stFlashStruct.byStructValid;
ReadBack.abyStructData[0] = CalSpace.stFlashStruct.abyStructData[0];
ReadBack.abyStructData[1] = CalSpace.stFlashStruct.abyStructData[1];
ReadBack.abyStructData[2] = CalSpace.stFlashStruct.abyStructData[2];
__builtin_software_breakpoint(); /* breakpoint here to inspect the ReadBack structure with the debugger */
Nop();
Nop();
/*
* Application process loop
*/
for(;;)
{
Nop();
Nop();
Nop();
__delay_ms(100);
}
}
I'm trying to emulate data from the 10-bit AEAT-6010 rotary encoder and send it out on the MISO pin of the SPI protocol on the ATtiny3217. The ATtiny act as a slave and receive a CLK and SS signal as input to respond to by outputting the data(encoder value). The encoder follows the SSI protocol to send data as shown below:
The problem arrises when trying to send 10 bits voer the 8 bit SPI protocol on the ATtiny. The master of the SPI protocol is the TMS320F2808 chip and from it I receive 11 clock pulses and the SS signal. The measured signals and data is shown below:
Here the data I try to send is 0b10 just for testing. I can see the correct data on the MISO line, but there is three 1's extra in the middle of the signal. This is with BUFEN=1 and BUFWR=1 in the SPI settings of the ATtiny as can be seen in the configuration below(without buffer mode the three 1's comes on the last 3 bits, and aslo the first bit(MSB) is read as a 1):
int8_t SPI_0_init()
{
SPI0.CTRLA = 0 << SPI_CLK2X_bp /* Enable Double Speed: disabled */
| 0 << SPI_DORD_bp /* Data Order Setting: enabled */
| 1 << SPI_ENABLE_bp /* Enable Module: enabled */
| 0 << SPI_MASTER_bp /* SPI module in slave mode */
| SPI_PRESC_DIV4_gc; /* System Clock / 4 */
SPI0.CTRLB = 1 << SPI_BUFEN_bp /* Buffer Mode Enable: enabled */
| 1 << SPI_BUFWR_bp /* Buffer Write Mode: enabled */
| SPI_MODE_0_gc /* SPI Mode 1 */
| 0 << SPI_SSD_bp; /* Slave Select Disable: disabled */
SPI0.INTCTRL = 0 << SPI_DREIE_bp /* Data Register Empty Interrupt Enable: enabled */
| 1 << SPI_IE_bp /* Interrupt Enable: enabled */
| 0 << SPI_RXCIE_bp /* Receive Complete Interrupt Enable: disabled */
| 0 << SPI_SSIE_bp /* Slave Select Trigger Interrupt Enable: disabled */
| 0 << SPI_TXCIE_bp; /* Transfer Complete Interrupt Enable: disabled */
return 0;
}
I have confirmed that the data fromat of the SPI module of the TMS320F2808 and the ATtiny is the same(read on falling clock edge). Is there something I am missing about how the buffers of the SPI work or the interrupts of the SPI? I'm not sure what to to in the ISR when enabling different interrupts(oher than clearing the flags). This is my main function(The ISR is empty for now):
int main(void)
{
/* Initializes MCU, drivers and middleware */
atmel_start_init();
sei(); // Enable global interrupts
/* Replace with your application code */
while (1) {
SPI_transmit(enc_data_L);
}
Where the SPI_transmit() is as follows:
void SPI_transmit(uint16_t enc_data)
{
// Then start the transmission by assigning the data to the SPI data register
SPI0.DATA = enc_data;
//SPI0.DATA = enc_data_H;
// Now wait for the data transmission to complete by periodically checking the SPI status register
//the SPI_IF is the only interrupt flag with a function in non-buffered mode.
while(!(SPI0.INTFLAGS & (SPI_RXCIF_bm)));
SPI0.DATA; //Dummy read to clear flag
}
I have also tried splitting the 16 bit data, as suggested here, but the problem remains also for 8-bit data. Hope this is enough background info. I'm thankful for any ideas!
in SPI_transmit after writing to the buffer you're waiting until transmission is completed. After that the input buffer is being fully transmitted and now is empty.
while(!(SPI0.INTFLAGS & (SPI_RXCIF_bm))); // waits until data is transmitted
RXCIF is set when there is a data in the receive buffer, i.e. the transmission of the output buffer was also completed.
Therefore, when next byte is being transmitted by the master, there is no new data yet in the output buffer to transmit. Probably the SPI module just repeats transmission of the previous byte.
So, instead of waiting for RXCIF flag, wait for DREIF flag, which will be set, when the transmission buffer is empty and ready for the next byte.
You can just ignore the incoming data, since you're not use it anyhow
void SPI_transmit(uint16_t enc_data)
{
// Wait until buffer is ready to get the next data byte
while(!(SPI0.INTFLAGS & (SPI_DREIF_bm)));
// Then start the transmission by assigning the data to the SPI data register
SPI0.DATA = enc_data;
// Don't care about read buffer
}
I want to configure a sensor over the I2C bus using the I2C-dev module.
The required I2C bus is up and running, however, I cannot seem to receive any data from the sensor. Could anyone please help me debug the below code. All the sensor registers are 8 bit.
int main()
{
int devFile=0;
const char *devFileName="/dev/i2c-1";
char writeBuf[2];
uint16_t readBuf[2];
uint16_t tempReading = 0;
/* Initialize I2C interface */
devFile = hdc2010_i2c_init(devFileName, HDC2010_ADDR);
/* Configuring the sensor and trigerring measurement */
writeBuf[0] = HDC2010_CONFIG;
writeBuf[1] = 0x57;
hdc2010_i2c_write(devFile, writeBuf, 2);
writeBuf[0] = HDC2010_INTERRUPT_CONFIG;
writeBuf[1] = 0x78;
hdc2010_i2c_write(devFile, writeBuf, 2);
writeBuf[0] = HDC2010_MEASUREMENT_CONFIG;
writeBuf[1] = 0x03;
hdc2010_i2c_write(devFile, writeBuf, 2);
/* Reading temperature data from the registers */
writeBuf[0] = HDC2010_TEMP_LOW;
hdc2010_i2c_write(devFile, writeBuf, 1);
readBuf[0] = hdc2010_i2c_read(devFile, 1);
writeBuf[0] = HDC2010_TEMP_HIGH;
hdc2010_i2c_write(devFile, writeBuf, 1);
readBuf[1] = hdc2010_i2c_read(devFile, 1);
/*
* Converting the temperature to readable format
* Formula Source : HDC2010 Datasheet
*/
tempReading = ((readBuf[1] << 8) | (readBuf[0]));
tempReading = ((tempReading/65536)*165)-40;
printf("\nTemp: %d\n",tempReading);
}
int hdc2010_i2c_init(const char *devFileName, int slaveAddr)
{
int devFile;
/* Opening I2C device file */
devFile=open(devFileName,O_RDWR);
if (devFile < 0)
{
printf("\nError opening the %s device file.\n",devFileName);
exit (1);
}
/* Selecting HDC2010 by its slave address */
if (ioctl(devFile,I2C_SLAVE,slaveAddr) < 0)
{
printf("\nFailed to select HDC2010(addr=%u)\n",HDC2010_ADDR);
exit (1);
}
return devFile;
}
void hdc2010_i2c_write(int devFile, char *buf, int numBytes)
{
write(devFile, buf, numBytes);
}
uint16_t hdc2010_i2c_read(int devFile, int numBytes)
{
uint16_t readBuf;
read(devFile, &readBuf, 1);
return readBuf;
}
Do I need to use SMBus commands or read/write is sufficient ?
Are there any test applications, like in the case of SPIdev ?
I don't know interface to your chip. There is a great range of possible ways to use I2C. But there is a very common way to access a device with 8-bit registers, so let's assume that is what you need.
To read a register, you want to generate the (simplified) primitive I2C sequence:
Start I2CAddr+Write RegAddr Start I2CAddr+Read [DATA] Stop
But what you are doing is this:
Start I2CAddr+Write RegAddr Stop
Start I2CAddr+Read [DATA] Stop
Basically, you need the read register operation to be a single transaction with one stop at the end and a repeated start between write mode and read mode. But what you are sending is two transactions.
You should not be using the read()/write() interface to i2c-dev. This interface is very simple and not suitable for most I2C transactions. Instead use the ioctl() interface and I2C_RDWR. This allows the appropriate transactions to be generated.
Since certain forms of transactions are very common, including the ones you most likely want, there is a library that has them coded already. Use i2c_smbus_read_byte_data() and i2c_smbus_write_byte_data() from the library in i2c-tools.
As for test programs, there is i2cget and i2cset, part of the above mentioned i2c-tools, that will be able to do what you want.
I have Raspberry PI 3 connected via SPI to AVR Attiny26, which in turn has a LCD connected to it. I am trying to get the SPI running,
Now, the issue is that when I set up the AVR for two wire mode and don't configure pull-up on PB1 (MISO commented out):
USICR = (1<<USIOIE)|(1<<USIWM1)|(1<<USICS1); // Enable USI interrupt - USIOIE=1
// Three wire mode USIWM1=0, USIWM0=1
// Two wire mode USIWM1=1, USIWM0=0
// External clock USICS1=1
//PORTB |= (1<<SPI_MISO); // Enable pull-ups on SPI port
DDRB = 0b01001010; /* Set PORTB bits: 7-4 as input
-- PB7 - Pushbutton (KEY1)/RESET
-- PB6 - Pushbutton (KEY2)/INT0
-- PB5 - ADC8 (T2)
-- PB4 - ADC7 (T1)
-- PB3 - PUMP
-- PB2 - SCK - 0 = external clock (input)
-- PB1 - MISO (output)
-- PB0 - MOSI (input) - */
ISR(USI_OVF_vect) {
disp[counter++] = USIDR;
if(counter==16)
counter = 0;
USISR |= (1<<USIOIF);
}
I get the string transfered and printed on the LCD.
However, when I change the AVR to work in three wire mode and/or enable PB1 pull-up, all I get is garbage. Neither the received characters match the ones sent, nor does their count.
Raspberry is the master here, providing all the clocking, the setup there is always the same (default, three wire mode) and the clock is reasonably slow.
int main(int argc, char **argv) {
int res = bcm2835_init();
printf("BCM2835 Init() = %d\n", res);
res = bcm2835_spi_begin();
printf("BCM2835 Begin() = %d\n", res);
bcm2835_spi_setClockDivider(BCM2835_SPI_CLOCK_DIVIDER_65536);
char data[16];
sprintf(data,"%s","<--Some data-->");
int len = strlen(data);
printf("Sent: %s\n", data);
bcm2835_spi_writenb(data, len);
exit(0);
}
Same results with spidev_test program using ioctl, so does not seem related to the library/Pi's program.
On top, what is puzzling me is that when I disconnect the wire from PB1 (MISO), I immediately start receiving garbage from Pi. As if Pi's SPI immediately starts clocking when PB1/MISO goes afloat.
What am I missing here?
Regretfully, I have to say that this one goes into the RTFM category.
After some reserch I found that Pi GPIO works with +3.3V. The Attiny was set to use+ 5V. After rewiring the AVR to work with 3.3V as well, everything seems to be working.
The reason why it worked in two wire mode is the absence of AVR's pull-up resistors (external required), which allowed Pi to use its own and drive the AVR pins in the range acceptable to both Pi and AVR. Enabling pull-ups on AVR would drive Pi's GPIO over the limit. Apparently no damage done, only unpredictable and hard to explain behavior.
My project is an audio spectrum analyzer, but I am stuck in displaying the ADC results, either on my LCD or on the Terminal of CodevisionAVR.
The project uses an ATmega16A, with an 7.37 MHz external oscillator. For an IDE I am using CodevisionAVR.
The audio spectrum analyzer takes its input through a 3.5 mm jack audio cable, this signal is amplified and filtered in order to select the frequencies between 0 and 4 KHz, and the output of this circuit is connected to PA0, which is the channel 0 of the ADC of the microcontroller.
For testing, I have set the ADC to work on 8 bits (read the most significant 8 bits), taking the internal 2.56V as voltage reference. I have decoupled AREF pin using a 10nF capacitor (I will change it to 100nF for a better noise reduction). The ADC is also in free running mode.
I am stuck in displaying the ADC results, either on my LCD or on the Terminal of CodevisionAVR (through the UART --- configured using the wizard).
This is the function I used for the ADC:
// Voltage Reference: Int., cap. on AREF
#define ADC_VREF_TYPE ((1<<REFS1) | (1<<REFS0) | (1<<ADLAR))
// Read the 8 most significant bits
// of the AD conversion result
unsigned char read_adc(unsigned char adc_input)
{
ADMUX=adc_input | ADC_VREF_TYPE;
// Delay needed for the stabilization of the ADC input voltage
delay_us(10);
// Start the AD conversion
ADCSRA|=(1<<ADSC);
// Wait for the AD conversion to complete
while ((ADCSRA & (1<<ADIF))==0);
ADCSRA|=(1<<ADIF);
return ADCH;
}
Main function of the code:
void main (void)
{
Init_Controller(); // this must be the first "init" action/call!
#asm("sei") // enable interrupts
lcd_init(16);
lcd_gotoxy(0,1);
lcd_putsf("AUDIO SPECTRUM");
delay_ms(3000);
lcd_clear();
while(TRUE)
{
wdogtrig();
TCNT1 = 0; //usage of Timer1 with OCR1A
TIFR |= 1<<OCF1A;
for(i=0;i<N;i++) {
while((TIFR & (1<<OCF1A)) == 0)
putchar(read_adc());
//adc_set[i] = adc_read(); //this is a second option
TIFR |= 1<<OCF1A;
}
//for(i=0; i<N; i++)
//printf("adc values: %d \n",adc_set[i]);
} //end while loop
}
N is defined as 32 = number of samples in 1 AD conversion.
The first error I see is using putchar() to write a number to the LCD.
The result of read_adc() is a number, not a string of ascii characters. You need to use sprintf to write the ADC result as a string into a buffer, then use lcd_putsf() to send the buffer to the LCD.