What is the device at 0x68 on I2C2 of Google Coral? - i2c

I am trying to connect an external RTC (addr 0x68, on Witty Pi 3) to my Google Coral dev board on I2C2 (bus 1). But i2cdetect shows a device at 0x68 even without my external RTC connected. I can't find anything in the docs (SOM or dev board) about a device on this bus. Lady Ada at Adafruit has found it also https://learn.adafruit.com/circuitpython-on-google-coral-linux-blinka?view=all#check-uart-i2c-and-spi-3027971-20 .
Does anyone know about this? Could point me at a doc?

I went to google support:
"0x68 is the oscillator for PCIe, I believe it needed for communication with the EdgeTPU, therefore it should not be disabled."
So Witty Pi 3 is a non-starter. I'm lucky there's a Witty Pi 4.

Related

Bidirectionally communicate a Roomba robot other than a Create model with raspberry pi

I've been trying to communicate different models of Roomba vacuum robots, 9xx and 6xx series, with a raspberry using the sci port of the roomba with no success. The sequence of steps have been:
connect pins 3 (rxd), 4 (txd), and 6 (ground) of the roomba port (5v) with a sparkfun logic level converter.
connect the output (3.3v) from the logic level converter to the gpio of the raspberry pi. Roomba Rxd to rpi txd, roomba txd to pi rxd, ground to ground.
connect rpi 5v to logic level converter HV and at the same time LV to gpio pin 1 (3.3v) for feeding high and low voltage required by the logic level converter.
disable serial console of the rpi
enable serial port hardware of the rpi
install and then open minicom in the rpi using this command
minicom -b 115200 -o -D /dev/serial0
place the roomba in the charging dock
I would now expect to read information about the charging process of the roomba in the minicom console but that's not happening.
Anyone knows if any of those steps is wrong?
My goals are to been able to read robots bump sensors in first place and then control movements of the robot from a pc using the rpi in between.
Thanks for any help.
Check this webseite. it's explaining exactly how to connect the roomba to the raspberry using an logic level converter
https://domoticproject.com/roomberry-surveillance-robot-roomba-raspberry-pi-zero-w-camera/

How can I connecti Raspberry pi 4 to pixhawk?

I want to create a connection between pixhawk and raspberry pi 4 model B.
When I connect the Pixhawk to the usb port of raspberry via micro-usb, I can send commands to the pixhawk with the drone-kit scripts on raspberry.
However, when I connect the telemtry2 port to raspberry's 14th and 15th GPIO pins (rx-tx) in pixhawks, the same script gives a heartbeat error.
I have done the configuration of uart pins with rasp-config. The /boot/config.txt file is as follows. Also, when connecting from usb, I use the connection string value "/ dev / ttyACM0" and "/ dev / serial0" when the UART pins are connected.
Via mission planner:
SERIAL 2 PROTOCOL = 2 , SERIAL2 BAUD = 921
I followed this link: https://ardupilot.org/dev/docs/raspberry-pi-via-mavlink.html
Since there is no GPS installed, I set the GPS and compass control values ​​to 0 on the mission planner. That's why the pixhawk is in arm state. (blue light)
Thank you..
Have you set the following parameters?
MAV_1_CONFIG = TELEM 2 (MAV_1_CONFIG is often used to map the TELEM 2 port)
MAV_1_MODE = Onboard
SER_TEL2_BAUD = 921600 (921600 or higher recommended for applications like log streaming or FastRTPS)
Reference:
https://docs.px4.io/master/en/companion_computer/pixhawk_companion.html#companion-computer-setup
there is an easy way to connect raspberry pi with cube autopilot. the companion board lychee
https://dronee.aero/pages/lychee

About Raspberry Pi 3 Power Consumption

I'm just bought a new Raspberry Pi 3 (and also 5V,2.5A Power Supply). And I'm totally a fresher to this so before to start using it I have some few question about its power.
I'm now connect my Pi with:
1. 1 Screen Monitor (Powered with another Power Supply) connecting through HDMI.
2. 1 Keyboard (USB port).
3. 1 Mouse (USB port).
4. 1 External Drive WD My Passport Ultra (with 3.0 USB cable) (USB port).
My question is does my Pi have enough power to handle all this above mentioned devices and if it is, can I use one more USB port for another device such as WD Passport and GPIO for a radiator fan ?.
Thank you for all your helps.
When your Pi will have not enough power for all peripherals you will see small yellow flash on screen. Then you should upgrade your power supply.

Getting 'Server is at 0.0.0.0' on serial monitor - in webserver

I bought a new Arduino Ethernet Shield and hooked it to the Arduino Uno.
I am trying to set the IP address of the device to 192.168.1.177 tried File-> Examples -> Ethernet-> Webserver.
When I upload this - I get a "server is a 0.0.0.0'message in serial monitor !
My IP is set to 192.168.1.177 and setup a mac address of 0xB8, 0x27, 0xEB, 0x98, 0x46, 0x61 in the webserver code.
Appreciate any help in setting this IP address. ( I tried other combinations as well )
The Arduino Ethernet shield is mounted on the Arduino Uno, and connections are lined up .
i fix this problem by pressing firmly the shield to the board
This can manifest from many different causes. I ran into this and figured out that in my case, my the USB port + cable were not allowing sufficient power to the Ethernet chip.
I have 3 cables, 6in, 3ft, and 6ft. Only the 6" one had sufficiently low voltage drop to power the shield.
I honestly couldn't believe it, but there was a 0.1V drop between the 6in and the 6ft cables. When plugged into A USB 3.0 port with the Arduino loaded, I measured ~4.5V for the working 6in cable vs ~4.4V for the non-working 6ft cable.
I have 3 types of USB ports: 1.1, 2.0, and 3.0. Only the USB 3.0 ports provided enough power to power the shield. Thus for my case, I had to use the shortest USB cable on the 3.0 port.
When the Arduino's 5V rail was sufficiently sagging, the 3.3 Linear Regulator entered dropout mode and on all the non-working configurations I saw ~3.1V on the Ethernet shield's 3.3V rail, which is apparently sufficient to cause this symptom.

How to interface raspberry pi and Mbed microcontroller using I2c?

I want to interface raspberrp pi and Mbed microcontroller through I2c bus. Both operate at 3.3v, I have connected Rpi SCL ----> mbed SCL, RPI SDA------> mbed SDA, RPI gnd -----> mbed gnd. After connecting all these things I run sudo i2cdetect -y 1 command its does not shows any more address connected to Rpi . Both the modules have internal pull up resistor
...
I²C is a master-slave protocol. That means one devices takes over the role of the master, and one (or multiple) devices connected to the I²C bus act as an I²C device.
In your case it seems like the raspberry pi is working as the master. To put the mbed device into I²C slave mode you have to instantiate one I2CSlave class.
Documentation and a tiny example is on the official site:
https://developer.mbed.org/users/mbed_official/code/mbed/docs/tip/classmbed_1_1I2CSlave.html