I am working on a project with the UART controls. I am attempting to simulate the sending and receiving of messages through the UART. The UART will be connected to a RS-485 transceiver in the real world but I will be providing the input/output through a test.c file.
Currently, I have to pause the execution of the program in the simulator, manually flip the bit and return the program back to execution again for the UART to send about byte.
My question to the group is can I auto-magically set the TXC bit to simulate a successful transfer of bytes? I am currently reading through Atmel's documentation and deciphering how to setup a stimuli file.
This would help out since I would like to make the communications testing more complicated the deeper I get with development.
Thanks,
Ryan
For me it is quite hard to understand your english...
set the TXC bit to simulate a successful transfer
On the real hardware you can't set TXC manually.
If you are talking about simulation environment, I only use http://www.nongnu.org/simulavr to do this kind of jobs. In this simulator you simply can add a c/c++-testprogram which runs on the host in the native host fashion and connect a simulated uart to the simulator which runs your avr program.
Related
I am a high school student, who is not very familiar with FPGAs and the Xilinx line.
I am running a ring oscillator module on a Zybo Z7 board. I am also running a counter module, which I want to sample at a high rate. I am currently sending the data through AXI to the ZYNQ processing system, and then using the inbuilt UART to USB buffer to send the data through a USB cable to my computer. On the computer side, I treat this input as a virtual serial line, and use a python script to take and log the data from an IOstream. This method takes very long, however, and I am trying to increase the sample speed. Thus, I was wondering if I could bypass the onboard PS, and connect the FPGA fabric directly to the UART buffer.
I have tried optimizing my PS code, which I have written in C. I have reached the point where it takes 30 oscillations of the onboard ZYNQ clock between samples. Now, however, I have created a newer and more reliable sampling framework in the FPGA logic, which requires a 'handshake' mechanism to start and stop the counter between samples. It takes a very long time for the PS to sample the counter, send the sample, and then restart the counter. Thus, the uptime of my sampling framework is a fraction of what I want it to be. Removing the PS would be ideal, as I know I can automate this handshake signal within the PL if I am able to connect it to a UART interface.
You can implement logic in the PL that can handle the UART communication thus bypassing the PS.
Here's an implementation you can try using:https://github.com/jakubcabal/uart-for-fpga
You would connect the UART pins to one of the Zybo Z7 Pmod ports and use an external USB to UART adapter such as this one, anyone would work as long it supports 3.3V: https://www.adafruit.com/product/5335
The adapter built into the board is connected to directly to the PS MIO pins and cannot be used by the PL.
As you probably guessed this question is not about a programming language but about arduino.
I'm making a big project which includes a GSM SIM900A module but it draws too much power.
I've looked up the datasheet but I didn't understand a lot as it references a DTR pin, something my module doesn't have.
Can someone tell me how to put it to sleep mode?
Any help will be grately appreciated!
Thanks in advance!
The GSM standard AT command for the setting of modem's level of functionality is AT+CFUN.
According to SIM900 AT commands guide its syntax is
AT+CFUN=fun[,rst]
Where:
fun: is the power saving mode
rst: is the reset flag
There are several possible values of fun parameter that can be supported or not depending on the modem vendor.
In order to reduce power consumption, SIM900A offers two possibilities:
AT+CFUN=0, means that the device is in sleep mode, and the AT interface is not accessible. Usually it keeps its network paging activities and its registration status to the network (it's not really clear from SIM900 guide). The device is woken up as soon as a wake up event occurs (for example an incoming SMS). Test it on your device.
AT+CFUN=4, that disable both TX and RX RF circuits. The AT interface remains reachable.
Usually first solution results in a bigger reduction of power consumption, but I suggest trying both of them in your specific board in order to understand what is the better choice for you.
I've been trying to establish serial (UART) communication between a Raspberry Pi Model B Revision 2.0 (checked the model like described on this page) and Arduino Mega 2560. I made a service on the Pi that writes to UART and then expects a message and a coworker programmed the Arduino with an echo program. While they were communicating, I had trouble receiving data, meaning that it was clustered in 8 byte pieces and I had to introduce a timeout for waiting between them (I was actually as much as available and calling select()for the next cluster but it turned to be 8bytes a cluster, except for maybe the last one. As explained in a question I found on this site, the programmer is the one to take care of the protocol and can not rely that the whole message will be ready to read at once (that is logical).
However, when I just connected Pi's TXD and RXD pins, no matter how much bytes I tried sending, it sends them in one go (I've gone up to a bit more than 256, that's more than enough for my purposes). I also have around 50 milliseconds of duration difference, measured directly from within the program, using gettimeofday() function.
So, could anybody clear things for me:
Why is this happening?
Is this difference in behaviour expected?
Is there a potential problem in either of the devices (if that can even be concluded from the given information).
Of course, any additional information is welcome, in case I forgot asking something that is deemed important.
Why is this happening?
I tried some time back communicating Arduino-Arduino and Arduino-Pi. I faced some problems with UART communication. However, you might want to keep same Baud rate on both the devices. With Pi, you might need to trigger an event if you receive data from Arduino. On the other side, if you code runs longer, then you might lose some data i.e. your Arduino code is running something else while Pi sends data over UART.
Is this difference in behaviour expected?
Yes. Arduino is a microcontroller based device while Pi is microprocessor based (runs on OS)
Is there a potential problem in either of the devices (if that can even be concluded from the given information).
I don't think there could be any hardware problem unless it is not functioning at all.
Also, because of this issues, I switched from UART communication to SPI communication. This solved my problem completely.
The ArduinoIDE writes firmware to my Arduino UNO but I want to handle logic and code outside the microcontroller on the computer with the microcontroller strictly being a sensor and the computer handling the logic.
How can I have the computer handle the logic and listen to sensors (output data to a computer) and respond (input commands to the board)?
Is this done with serials? How do I get started with this?
I know how to code, I just need help understanding how to get the hardware to talk to one another. Arduino to computer, computer to arduino.
For example, I have a thermal sensor on the board, how can I have bi-directional communication where the output of temperature would go to a program on my computer and respond to the board to turn on an LED or other command based on statements on the computer.
All help is appreciated.
There is a tutorial on arduino.cc how to read a sensor on arduino en display the values in processing.
There is also a tutorial to turn on a led with a command from a pc.
If you want to do real complicated things I suggest that you take a look at Firmata
I downloaded several software that provide virtual COM ports. These COM ports do appear in the Device Manager and can be selected for upload from the Arduino IDE, menu Tools -> Serial Port -> COM3. It starts uploading and reaches 90% and then it either times out or just does nothing.
I want to upload onto the virtual COM port so I could then read the compilation output files in another program. I don't want to use my Arduino at all, and I don't want to manually get the verbose output files when uploading. This problem doesn't happen when I upload on the real Arduino.
The application should work on all platforms. This task seems easy on Linux, and I am facing the stated problem on Windows and any help with Mac would also be useful.
The application will be an educational tool for hardware simulation and visualization trying to give a more hands-on experience for users than other simulators out there. So may be this will give you an idea of why I want to do so.
How can I get started?
I think you might be assuming that uploading code to Arduino is one-way communications: this would be like putting strawberries in a blender, and a Daquiri comes out. If that was true, you could just take whatever the IDE dumps to the serial port, save it to a file, and you have an Arduino binary. (Skip to TL;DR if not interested in details. Upshot: this assumption is not correct).
The 1-way communication assumption is not entirely correct: there is a program on the Arduino (called "a bootloader") which is responsible for communicating with the programmer ("programmer": a program that programs the Arduino, assume it is the Arduino IDE for now). In their most "natural" state, the Arduino CPUs cannot be programmed across serial lines. Rather these chips are programmed either via the in system programming (ISP) or via the JTAG protocol. The bootloader is a program that runs on an Arduino CPU and loading of sketches/programs over the serial port. This program runs at startup and looks for programming commands over the serial port.
If it discovers that a programmer is trying to communicate programming information, it will read the compiled Arduino binary coming over the serial link, store it in flash memory, send it back to over the serial link for verification, and if everything is successful, exit and launch the stored sketch. If no programming information appears on the serial port, that is, no programmer is trying to write a new sketch, then the bootloader simply quits and launches the program already stored in flash.
TL;DR: In order to implement a pseudo-Arduino on your serial port you must write a program some code that simulates an Arduino (bootloader) on the other end of your virtual serial port. So when a programmer/IDE says to Arduino "are you there?" your program will respond "yes!", just like an Arduino would.
The default Arduino bootloader is STK-500 compatible: that means that it implements STK-500 commands - the reference for which can be found here. If you decide to do this, then the easiest thing might be to start with an existing bootloader, such as Arduino's or AdaFruit's (there are others too), and modify it. Such a bootloader would have all the commands already implemented, and since it is written in C (I wouldn't choose an assembly bootloader to modify :), it should be easy enough to modify.
Alternatively, you might decide that STK-500 is too difficult to implement. If this is the case, you can use any programmer protocol that Avrdude supports: Avrdude is a program for programming AVR chips, and Arduino IDE uses Avrdude internally to send the sketch to the Arduino. If you do this, then you'd have to change the settings in Arduino IDE for which programmer you are using.
Personally, I think STK-500 compatible is the best option for this, but YMMV.