Regarding Raspberry Pi Zero W - USB Access from GPIO Header - raspberry-pi

I am using Raspberry Pi Zero W for my project. I want to use GPIO Pins as USB instead of the on-bard MicroUSB connector. Is it possible?
Thanks in advance.

Sorry, the GPIO connector does not include any USB signals.
There are some USB hubs that connect to the test pads on the back side of the zero, e.g this one sold by Adafruit: https://www.adafruit.com/product/3298
If you are happy with just one USB port but don't like the micro connector, you could probably solder your own connector with a short pigtail lead to the same test points.
You can't use the micro usb connector at the same time as a hub or usb connector attached to the test pads as they are the same signals as in the micro connector.
The test pads p22 and p23 can be seen in this schematic:
https://github.com/raspberrypi/documentation/blob/master/hardware/raspberrypi/schematics/Raspberry-Pi-Zero-V1.3-Schematics.pdf

Related

How to send data from STM32 USB port to Raspberry PI USB port?

I want to send data through USB between STM32 and Raspberry Pi. I don't want to use USB to Serial convertor, but instead have a actual USB Connection (maybe CDC class). I have to send data at high rate (Full speed). Please guide on how to achieve this?
A USB-serial connector is simply a microcontroller implementing a USB CDC/ACM virtual COM port and bridging to a UART which you would connect to a microcontroller's UART interface.
In your case you can simply implement the CDC/ACM directly on the STM32 using either of its USB device controller peripherals (USB support varies depending on the specific device https://www.st.com/resource/en/application_note/dm00296349-usb-hardware-and-pcb-guidelines-using-stm32-mcus-stmicroelectronics.pdf).
How you actually implement that will depend on what specific part, and what library or framework ecosystem you are using (e.g. SPL, CubeMX, Mbed). There are reference implementations, examples, drivers and libraries for all of these.
Your milage may vary, but I have measured ST's own USB library and example CDC/ACM virtual COM for STM32F1xx on a 72MHz MCU achieving 700kbits/s. Note that the performance is independent of the baud rate you might set on the host when you open the he VCP. Setting the baud rate simply sends a control packet to the device that can be used to set the baud rate of a UART in bridging applications. In your case such control packets can be ignored. There are similar packets for modem control signals such as DTR, RTS, CTS and RI, which you might choose to us for flow control or other signalling.

Do I need a level converter for Raspberry Pi and STM32 to communicate via GPIO(UART) port?

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.

How can I stream Kinect V2 tracking data from PC to Raspberry Pi 3 through WiFi?

I'm currently working with Kinect v2. I can do all sort of stuff on PC with it. What I want to do next is, to get the data I want on PC and control the Raspberry Pi with that data (for example, I will move the Pi with motors when I tilt my head to right). I have sorted out the motors and everything but I just don't know how to use that tracking data I have on PC to control the Pi.
I hope the question makes sense, i'm just extremely new to both Pi and Kinect.
Thanks for the help!
The first step is to choose the bus that will connect the
PC to the Raspberry PI.
Your options are:
Serial bus: Pi Serial tutorial,USB Serial to Pi cable
Network Socket (cable/wifi): Socket client/server c++ examples
i2c: i2c windows PC, Configuring i2c on Pi
I believe that the i2c or serial bus will be the easiest to start
with. But in the end all 3 options need to set up the connection, and send and receive bytes / byteArrays.

Raspberry Pi and LCD screen

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.

Coding Raspberry Pi with an ADC - SPI

I am trying to connect an analogue to digital converter to the raspberry pi. As far as I am able to understand, the RPi doesn't support Bi-directional SPI mode. The adc I am using says it is SPI compatible but only has the inputs SCLK, CNV and outputs CLKOUT+ and CLKOUT- and SD0+ and SD0-. This leads me to understand that it will only work with bi-directional SPI as there is only the serial data out. I am thinking of using a PWM for CNV (which I think CE), GPIO clock for SCLK and then an interrupt on the falling edge of the GPIO clock to just digitally read each bit from the adc. I don't understand SPI in detail but from what I've read quite often it requires sending data in order to receive it. Do you know if the setup I mentioned (without using SPI) will work? Or am I missing something about SPI and the adc will work with that while not in bi-directional mode?
We are using the Raspberry Pi 3 b
adc - http://cds.linear.com/docs/en/datasheet/232316fa.pdf
Thanks for any help you can provide.
Read the data sheet carefully, in particular pages 8 and 9. I suggest that you tie CMOS/LVDS pin to ground to enable CMOS mode. Then use only the "+"-pins. Use the SCK for SPI clock, SD01+ for SPI data input to the Rpi. Connect a GPIO pin to CNV.
Also observe that the RPi runs at 3.3V, and the ADC's max rating is also 3v3, that is running the IC right to the edge.