I hope you can help me. I am trying to build a robot but I am kind of stuck. The Arduino Mega is controlling the stepper motors drivers of the robot. The odroid-x is a single board computer that has installed linaro ubuntu and eclipse c++. All the programming is done in C++ and OpenCV is an image processing library.
The odroid-x has only as input a color camera. Therefore, the information from the camera is received and is processed in eclipse. Then, according to the information that is received, the odroid-x should send different integers to the arduino. The arduino should have a program already uploaded in itself, so it will be waiting for an integer and that integer is going to determine what the arduino is going to send to the drivers.
My questions are the following:
How can I do a serial communication between the arduino and the odroid-x?
How can I send information from eclipse to the arduino with a serial connection?
Thanks so much for any guide you can give me
First, be very, very, very careful. The ODROID boards use 1.8V signalling, so hooking up your 3.3V or 5V Arduino to the pins that expect no more than 1.8V will give you a burnt ODROID-X. It is possible to hook these two boards together if you put a level converter between them, and Sparkfun and Adafruit have some of those converters available. There is even a 1.8V reference voltage pin available... one of the pins that go to the LCD panel RGB-to-LVDS converter board puts out a constant 1.8V.
You could use either the four pins of the little white connector, or UART1, as a serial port, or you can use some of the pins in the 50-pin GPIO block as UART4. There are board schematics available on Hardkernel's website. These two UARTs show up as /dev/ttySAC0 (UART1) and /dev/ttySAC3 (UART4).
I don't know how to talk to those UARTs from a program, personally, but I know there are serial communications libraries available for python from watching threads pop up on the ODROID forums.
Related
I am using a STM32F030F4P6 MCU and a LCD 2004 with PCF8574T I2C display driver. I have tried the library from this tutorial: https://controllerstech.com/interface-lcd-16x2-with-stm32-without-i2c/. I have found a datasheet for the PCF8574T device, but there are no commands specified in there. I am quite new in the field, but I already communicated with other devices over I2C and SPI and got them to work. Can somebody tell me what I am doing wrong, or at least show me where to get a datasheet with commands for the device? I am sorry in advance if this is a noob question.
As already mentioned, PCF8574T - is an i2c expander. So you need to write a driver which manipulates data pins on PCF8574T in way described in tutorial you found.
Check the arduino code for this type of LCD. It may save your time/ https://github.com/fdebrabander/Arduino-LiquidCrystal-I2C-library
If you have an Arduino board, you can test your LCD according this tutorial https://create.arduino.cc/projecthub/Arnov_Sharma_makes/lcd-i2c-tutorial-664e5a
Nice to know that your device still alive before debug the code.
I want to connect an STM32F407 Discovery board with a Raspberry Pi 4 Model B.
And I want to use UART as communication so I plan to use PD5&6 on STM32 and Pin8&10 on RPi. But after looking up online it says that the voltage of a STM32 port is 5V and RPi is 3.3V, so it seems that I need a level converter between them?
And there are also some articles says that not all the STM32 port are 5V, some are 3.3V. But I cannot find any of that information in the datasheet. Can anyone tell me where can I find these information?
Thank you very much ~ ~
The STM32 uses 3.3V as well. But it's 5V tolerant.
Just go ahead and connect them. There is no voltage difference.
You should have a look at the reference manual for that discovery board. It is here: STM32F407 Reference Manual.
There should be no issue connecting UARTs between those boards. Just remember to connect the TX from one to the RX of the other and vice versa. You can also use the CTS/RTS for flow control, but that isn't necessary as long as you are using baud rates of 115200 or slower.
Something else that I would recommended is to power the Raspberry Pi from the Discovery board. There should be pins for suitable power on the discovery. This is important because it gets both boards using the same power and ground so that the UART logic levels are consistent between the two. This may not be necessary, but I have had issues trying to connect two Nucleo boards SPI busses together if I didn't power one board from the other.
Good day
The problem:
I am trying to connect/flash/debug a Olimax STM32-E407 dev board over SWD and I am not able
When trying to connect, using CubeProgrammer, I get: "No STM32 Target Found"
What I have tried:
I have connected a ST-link V3 mini to the pinout of the the 20pin header of the Olimax board including 3.3V, GND, SWDIO (PA13/Pin7), SWCLK (PA14/Pin9) and NRST (Pin15).
I am powering the powering the board from a power supply into the power jack
All jumpers and solder bridges are in stock places.
I have also tried manually pulling NRST to ground and doing a full chip erase, but that has not worked either.
I have used these ST-link debuggers on other boards I made and it works perfectly fine
I have 3 Olimax boards and none of them work
Any help would he hugely appreciated.
Debugging problems on microcontrollers have two general common methodes.
Hardware Problems:
In this part, it is highly recommended that use an oscilloscope to monitor circuit.
Make sure the microcontroller is powered with a correct and stable power supply.
Check the soldering quality and there is no short circuit on the board (especially between ground pins and other pins).
Check the NRST pin is high when the board is powered.
Remember that this reset is active low so during programming or debugging this pin should be high. Also, check this pin is debounced with a capacitor.
Also you can check the JTAG pins signals with an Oscilloscope to check if the programmer device is working fine.
Sometimes adding a capacitor between debugging pins and GND increases the bus capacitance and solves the problem. The value of the capacitor should be found by trying.
Software Problems
Check the programmer driver is correctly installed on your PC.
Check the programming method is true(for example maybe the board is designed to be programmed with SWD, not JATG).
Sometimes reducing the programming clock of the programmer solved the problem.
If all of these methods didn't work and you are sure that the board is fine, probably the programmer is broken, so change the programmer with another one.
My STLINKV2 is not working anymore, not detected by Linux, it failed after the first successful flash. I ordered a new one but it will take 60+ days to arrive. Meanwhile I have heard on Youtube you can program Bluepills directly by connecting cut open USB cable to certain pins and then using a jumper. But I cannot get any precie information on this, is this really possible and how?
You should use the embedded bootloader. You can flash it through several interfaces. Look at AN2606, maybe you can find an already written flasher. Good luck STM32CubeProgrammer handle it.
If you intend to program it through usb, look also at AN3156 all protocols document are referred in chapter 2 of AN2606
THOSE AREN'T CUT OPEN USB CABLES they are USB to serial adapters for arduino's bootloader
They connect them like this:
The problem is that this requires the Arduino STM32 bootloader to be flashed in it.
Another option will be to use STM32CubeProg this program allows you to program your stm over
Serial
SPI
I2C
USB
You'll need to set the BOOT0 and BOOT1 pins to the correct value (HIGH slash LOW) to allow it to go in flash mode during boot.
Here is semi outdated tutorial which tells most of the steps to program a STM using serial. (the Flash Loader Demonstrator is outdated and you should use STM32CubeProg)
I want to build a small project which will monitor some devices(pump,ac etc) status(on/off, current/voltage level etc). I have decided to use raspberry pi 3 as a server. I am thinking about scada. is it efficient to do these works? also i am not familiar to scada. is there anyone to guide me--
where should i start?
what is the suitable software for doing it??
You could just use Python and the RPi.GPIO module to control and monitor the GPIO pins on the Raspberry. Python is powerful, open-script and easy to get into.
You would need to develop a bread-board to protect your Raspberry and allow for monitoring higher voltages.
Some example code on using GPIO with Sockets here: https://github.com/matzpersson/raspberry-gpio-sockets
You may use ScadaLTS on Raspberry.
In ScadaLTS have available modbus protocol among many others.
This is web oriented software with graphics views drag and drop editor.
For now you may read GPIO data programmatically to file and use ASCII File Reader DataSource.
We plan to have datasource dedicated for GPIO.
ScadaLTS based on ScadaBR - fast tutorial https://www.youtube.com/watch?v=JjOQWwoaQuQ.
you could also check out mySCADA. they make a solution for Raspberry pi at http://www.smarthouse.cloud
you can use the GPIO on the Pi or talk to industrial PLC's.