I am building a system which uses a remote attached to the RPi with a ribbon cable from about 3ft away.
The remote has buttons on it which connect the Raspberry Pi's
GPIOs to GND.The system works beautifully when I use a breakout board, plugging the ribbon cable into that.
However, when I tried to connect the ribbon straight to the RPi,
pressing 1 button often triggers 2 others.
Why would this happen only at the RPi, but never at the breakout board? Any help would be much appreciated.
Before I could preview the schemtaic circuit of the breakout board. I doubt it is caused by the drive capability of the pi board,you can mesure and compare the voltage on the button end between using breakout board and without it, it's really a hardware issue and only way to solve is to check the schematic circuit and measure. by the way, the question you asked is off-topic here.
Related
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.
I have two nucleo boards (F4339ZI and F303K8) and neither of them show up as USB devices when I plug them into a computer via the USB port (CN1 - the USB micro port on the ST-Link, not the USB port for the board itself).
I have tried multiple host USB ports, with and without a USB hub, across two different computers, one running OS X and one running Linux. I have tried at least 6 different cables. The OSX machine is using a USB-C to USB-A converter (if that's the correct terminology). The Linux machine has USB-A ports.
In no case does the device show up using lsusb under Linux or system_profiler SPUSBDataType under OSX. Needless to say STM32CubeIDE and st-info can't see the boards. Other USB devices are functional.
The COM LED is slow blinking red which the manual (https://www.st.com/resource/en/user_manual/dm00244518-stm32-nucleo144-boards-stmicroelectronics.pdf) says means USB enumeration hasn't completed (matching what is seen from the OS level).
The boards successfully run their factory supplied blink programs when powered on.
I have tried (with the F4395I) moving JP3 to VIN so the board doesn't power up which should just leave the ST-Link running - still no enumeration though.
I tried connecting to a USB charger with JP1 off (and JP3 on U5V) and the board powers up and blinky runs. The manual referenced above says:
In case the board is powered by a USB charger, there is no USB enumeration, so the green LED LD6 stays in OFF state permanently and the target STM32 is not powered.
But everything works for me - LD6 goes a steady green as it does when connected to a computer.
Given it happens with multiple computers, OSs, cables and Nucleo boards I assume the error lies with me, the common factor in all the tests. This is my first use of Nucleo boards so I may well have a mis-assumption.
Out of frustration and lacking anything else to try I dug up every micro USB cable I could find. One had chokes on each end and magically, using that cable, everything just works as expected.
Can it be that I have at least 10 broken USB cables? I don't have an easy way to test them but I guess they might not have the data lines wired to save cost if manufacturers assumed people would only charge phones with them. I don't recall where they all came from...they have just accumulated in a box of USB cables.
Perhaps the Nucleo board sensitive to some horrible interference floating around my room?
Sorry for the noise! Broken cable was genuinely one of the things I suspected - but not 6 of them...
I have a pi3 and I want to connect it to my monitor that came from my old computer. The problem is that it is a monitor and a webcam combined, and the cable is too wide for the connectors. I was wondering if I could use the gpio pins, and if so, which ones and how to connect it all.
You can connect them using HDMI-DVI or HDMI-VGA converter.
I am assuming monitor cable to be DVI or VGA. If you can mention details of the cable, you can get precise answer.
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.