I am trying to send an echo from a shell script on some event.
echo naval > /dev/cu.usbmodem1421
on this /dev/cu.usbmodem1421 serial port my Blend Micro Atmega32u4 Board is listening.
But every time I send an echo it says, resource busy.
I am not sure what can be the solution?
Arduino code:
int incomingByte = 0; // for incoming serial data
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// send data only when you receive data:
if (Serial.available() > 0) {
// read the incoming byte:
incomingByte = Serial.read();
// say what you got:
Serial.print((char)incomingByte);
}
}
have you tried killing the process ?, it seems it is hanging waiting a bit broad of a question but it could be caused by numerous things.
Related
I'm currently implementing a driver for the WINC1500 to be used with an ATMEGA32 MCU and it's getting stuck on this line of "while(!spi_is_tx_empty(WINC1500_SPI));". The code builds and runs but it won't clear what's inside in this function to proceed through my code and boot up the Wifi Module. I've been stuck on this problem for weeks now with no progress and don't know how to clear it.
static inline bool spi_is_tx_empty(volatile avr32_spi_t *spi)
{
// 1 = All Transmissions complete
// 0 = Transmissions not complete
return (spi->sr & AVR32_SPI_SR_TXEMPTY_MASK) != 0;
}
Here is my implementation of the SPI Tx/Rx function
void m2mStub_SpiTxRx(uint8_t *p_txBuf,
uint16_t txLen,
uint8_t *p_rxBuf,
uint16_t rxLen)
{
uint16_t byteCount;
uint16_t i;
uint16_t data;
// Calculate the number of clock cycles necessary, this implies a full-duplex SPI.
byteCount = (txLen >= rxLen) ? txLen : rxLen;
// Read / Transmit.
for (i = 0; i < byteCount; ++i)
{
// Wait for transmitter to be ready.
while(!spi_is_tx_ready(WINC1500_SPI));
// Transmit.
if (txLen > 0)
{
// Send data from the transmit buffer
spi_put(WINC1500_SPI, *p_txBuf++);
--txLen;
}
else
{
// No more Tx data to send, just send something to keep clock active.
// Here we clock out a don't care byte
spi_put(WINC1500_SPI, 0x00U);
// Not reading it back, not being cleared 16/1/2020
}
// Reference http://asf.atmel.com/docs/latest/avr32.components.memory.sdmmc.spi.example.evk1101/html/avr32_drivers_spi_quick_start.html
// Wait for transfer to finish, stuck on here
// Need to clear the buffer for it to be able to continue
while(!spi_is_tx_empty(WINC1500_SPI));
// Wait for transmitter to be ready again
while(!spi_is_tx_ready(WINC1500_SPI));
// Send dummy data to slave, so we can read something from it.
spi_put(WINC1500_SPI, 0x00U); // Change dummy data from 00U to 0xFF idea
// Wait for a complete transmission
while(!spi_is_tx_empty(WINC1500_SPI));
// Read or throw away data from the slave as required.
if (rxLen > 0)
{
*p_rxBuf++ = spi_get(WINC1500_SPI);
--rxLen;
}
else
{
spi_get(WINC1500_SPI);
}
}
Debug output log
Disable SPI
Init SPI module as master
Configure SPI and Clock settings
spi_enable(WINC1500_SPI)
InitStateMachine()
INIT_START_STATE
InitStateMachine()
INIT_WAIT_FOR_CHIP_RESET_STATE
m2mStub_PinSet_CE
m2mStub_PinSet_RESET
m2mStub_GetOneMsTimer();
SetChipHardwareResetState (CHIP_HARDWARE_RESET_FIRST_DELAY_1MS)
InitStateMachine()
INIT_WAIT_FOR_CHIP_RESET_STATE
if(m2m_get_elapsed_time(startTime) >= 2)
m2mStub_PinSet_CE(M2M_WIFI_PIN_HIGH)
startTime = m2mStub_GetOneMsTimer();
SetChipHardwareResetState(CHIP_HARDWARE_RESET_SECOND_DELAY_5_MS);
InitStateMachine()
INIT_WAIT_FOR_CHIP_RESET_STATE
m2m_get_elapsed_time(startTime) >= 6
m2mStub_PinSet_RESET(M2M_WIFI_PIN_HIGH)
startTime = m2mStub_GetOneMsTimer();
SetChipHardwareResetState(CHIP_HARDWARE_RESET_FINAL_DELAY);
InitStateMachine()
INIT_WAIT_FOR_CHIP_RESET_STATE
m2m_get_elapsed_time(startTime) >= 10
SetChipHardwareResetState(CHIP_HARDWARE_RESET_COMPLETE)
retVal = true // State machine has completed successfully
g_scanInProgress = false
nm_spi_init();
reg = spi_read_reg(NMI_SPI_PROTOCOL_CONFIG)
Wait for a complete transmission
Wait for transmitter to be ready
SPI_PUT(WINC1500_SPI, *p_txBuf++);
--txLen;
Wait for transfer to finish, stuck on here
Wait for transfer to finish, stuck on here
The ATmega32 is an 8-bit AVR but you seem to be using code for the AVR32, a family of 32-bit AVRs. You're probably just using the totally wrong code and you should consult the datasheet of the ATmega32, and search for SPI for the AVR ATmega family.
I'm trying to turn on an LED connected to an Arduino from a ruby file, as well as sending a string from that Arduino to my ruby file / terminal. (I'm doing these two things separately, to avoid potential problems).
I'm using a USB port to connect Arduino - Computer, and the serialport gem. I'm working in Linux.
To receive the string on my computer:
I have followed several tutorials that all recommend to run this ruby file:
require 'serialport'
port_str = '/dev/ttyACM0'
baud_rate = 9600
data_bits = 8
stop_bits = 1
parity = SerialPort::NONE
sp = SerialPort.new(port_str, baud_rate, data_bits, stop_bits, parity)
while(true) do
message = sp.gets.chomp
puts message
end
And uploaded this to the Arduino:
uint8_t c;
int i;
void setup() {
Serial.begin(9600); // set baud rate
pinMode(13, OUTPUT); // set pin 13 to be output for LED
digitalWrite(13, LOW); // start with LED off
}
void loop() {
while (Serial.available() > 0) { // check if serial port has data
// writes to computer
Serial.println("Hello world");
}
}
I got this error message: undefined method `chomp' for nil:NilClass (NoMethodError). When getting rid of .chomp, at some point I could get some parts of "Hello world" being printed on my terminal, such as "Hell", and then far later "o w", etc.
Now I don't even get anything anymore.
To turn the led on:
In the ruby file, I replaced the message part by
sp.write('a')
And in the arduino file,
void loop() {
while (Serial.available() > 0) { // check if serial port has data
c = Serial.read(); // read the byte
if (c == 'a'){
digitalWrite(13, HIGH); // turn on LED
delay(500); // wait 500 milliseconds
digitalWrite(13, LOW); // turn off LED
delay(500); // wait 500 milliseconds
}
}
}
The led turns on if I remove the condition (c == 'a'), but obviously I need it if I want the arduino to perform different actions.
I'm new to Serial communication, so I'm not quite sure where the error comes from, since I feel somehow some data seems to be transmitted.
socketCAN connection: read() not fast enough
Hello,
I use the socket() connection for my CAN communication.
fd = socket(PF_CAN, SOCK_RAW, CAN_RAW);
I'm using 2 threads: one periodic 1ms RT thread to send data and one
thread to read the incoming messages. The read function looks like:
void readCan0Socket(void){
int receivedBytes = 0;
do
{
// set GPIO pin low
receivedBytes = read(fd ,
&receiveCanFrame[recvBufferWritePosition],
sizeof(struct can_frame));
// reset GPIO pin high
if (receivedBytes != 0)
{
if (receivedBytes == sizeof(struct can_frame))
{
recvBufferWritePosition++;
if (recvBufferWritePosition == CAN_MAX_RECEIVE_BUFFER_LENGTH)
{
recvBufferWritePosition = 0;
}
}
receivedBytes = 0;
}
} while (1);
}
The socket is configured in blocking mode, so the read function stays open
until a message arrived. The current implementation is working, but when
I measure the time between reading a message and the next waiting state of
the read function (see set/reset GPIO comment) the time varies between 30 us
(the mean value) and > 200 us. A value greather than 200us means
(CAN has a baud rate of 1000 kBit/s) that packages are not recognized while
the read() handles the previous message. The read() function must be ready within
134 us.
How can I accelerate my implementation? I tried to use two threads which are
separated with Mutexes (lock before the read() function and unlock after a
message reception), but this didn't solve my problem.
I have an Arduino Mega 2560 and a sim900 gsm module.
I interfaced them successfully and written the code. Its working, but I can only send 1 sms at a time in the while loop. That means when I write a while loop to execute the sendsms() 5 times by using a while loop. Only one sms is sent.. and it stops...
The code is below:
#include <SoftwareSerial.h>
#include <String.h>
SoftwareSerial mySerial(52, 53);
void setup()
{
mySerial.begin(19200); // the GPRS baud rate
Serial.begin(19200); // the GPRS baud rate
delay(500);
}
int x = 0;
loop()
{
while (x<5)
{
SendTextMessage();
x++;
}
}
void SendTextMessage()
{
mySerial.print("AT+CMGF=1\r");
delay(100);
mySerial.println("AT + CMGS = \"+94776511996\"");
delay(100);
mySerial.println("hey wow");
delay(100);
mySerial.println((char)26);
delay(100);
mySerial.println();
}
You can't just dump your AT commands at the SIM900 with 100mS delay, and expect it to work. The SIM900 responds to AT commands (typically with "OK"), and you should wait for this response before issuing the next command. You can getaway with ignoring these responses only if you provide enough delay between AT commands to make sure that every command is only sent after the SIM900 had enough time to respond to the previous one. To make a quick verification of this, I would add a delay(10000) - a 10 seconds delay - at the end of your sendTextMessage() function. This will (probably) give the SIM900 enough time to complete the SMS transmission before moving on to the next one.
void SendTextMessage(){
mySerial.write("AT+CMGF=1\r\n");
delay(1000);
mySerial.write("AT+CMGS=\"+94776511996\"\r\n");
delay(1000);
mySerial.write("Test");
delay(1000);
mySerial.write((char)26);
delay(2000);
}
I am using OpenCV in Visual Studio 2010 to track an object, and I am trying to send a value to the Arduino to rotate servos attached to the camera. I am using an Arduino Uno. I have completed the C++ code that tracks the object and determines which direction the camera needs to be rotated, but I am having trouble sending this data to the Arduino. I am currently trying to use an RS-232 cable for this. I am using a Type-B USB cable to program my Arduino and an RS-232 to try to send the data from Visual Studio to the Arduino. Here is my code for the Visual Studio serial communication:
int portspeed(int centerpix, int xmid)
{HANDLE hDevice = CreateFile(L"COM5",GENERIC_READ | GENERIC_WRITE,FILE_SHARE_READ | FILE_SHARE_WRITE,NULL,OPEN_EXISTING,0,0);
DCB lpTest;
GetCommState(hDevice,&lpTest);
lpTest.BaudRate = CBR_9600;
lpTest.ByteSize = 8;
lpTest.Parity = NOPARITY;
lpTest.StopBits = ONESTOPBIT;
SetCommState(hDevice,&lpTest);
DWORD btsIO;
if (centerpix<xmid)
{
char test[] = "2";
WriteFile(hDevice,test,strlen(test),&btsIO,NULL);
cout << "Turn right " << test << endl;
}
else
{
char test[] = "3";
WriteFile(hDevice,test,strlen(test),&btsIO,NULL);
cout << "Turn left " << test << endl;
}
return 0;
}
On the Arduino code side I have this, which I am using to attempt to light two different LEDS to see if the program is able to correctly communicate which direction it needs to rotate:
int incomingByte = 0; // For incoming serial data
void setup()
{
Serial.begin(9600); // Opens serial port, sets data rate to 9600 bit/s
}
void loop()
{
// Send data only when you receive data:
if (Serial.available() > 0)
{
incomingByte = Serial.read();
if (incomingByte==50) //if =2
analogWrite(9,100);
else
analogWrite(9,0);
if (incomingByte==51) //if =3
analogWrite(10,50);
else analogWrite(10,0);
delay(3000);
}
else
analogWrite(9,255);
}
My interpretation is that I need to start the C++ program (which continuously sends the data over the serial communication), and then attach the TX pin from the RS-232 into the RX pin (digital 0) on the Arduino. When I try to upload the program to the Arduino I am given an error,
avrdude: stk500_getsync(): not in sync: resp=0x00
This only occurs when I have a wire going into the RX pin, even if this wire is not connected to anything. I believe that this error occurs because the RX is looking for an input with a baud rate of 9600, but it still gives me this error when the C++ program is running and sending the data with a rate of 9600.
How can I send a value from a Visual Studio project doing real time image processing on a laptop to an Arduino via serial communication?
Speaking as someone with limited Win32 experience (more of a .NET guy, really), I think your problem may be in write buffering.
By default, writes to a file or port are buffered in memory. Perhaps the write is never getting sent to the port as you are never closing the file handle nor calling [FlushFileBuffers][3].
Try adding this prior to return 0;:
//After a time, sensitive write
FlushFileBuffers(hDevice);
//or, more properly for the end of the program.
CloseHandle(hDevice);