tomasz-lewicki
commented
3 years ago Hi @nanogear !
Neat idea! I thought about it a little bit before, but never implemented it :slightly_smiling_face:
The only way of controlling neopixels I knew about was by using a bit-banged protocol for the ws2812, but that required 100% of one CPU core, so I gave up on this. Looks like NeoPixel_SPI library lets you use SPI hardware, without hogging the CPU :+1:
Let me take a look at the library and get back to you! :slightly_smiling_face:
nanogear
I am trying to use Neopixels on this project,. Recently Adafruit coded some libraries for the Neopixels that are useful in the Jetson Nano using CircuitPython. It works pretty nice...
I want to make the Neopixel stay ON with green colour when the Jetson Nano be in fever screening mode and when a 37.5 C temperature is detected, the Neopixel changes the colour to red for example... I need some help to incorporate it to the Tomasz project please.
Thank you.
Here is a simple tutorial to make Neopixels work with the Jetson Nano:
Install Pip3 if not already installed:
sudo apt-get install python3-pipReboot
Install Adafruit-Blinka 5.8.0:
pip3 install Adafruit-BlinkaEnable SPI on Jetson Nano:
sudo /opt/nvidia/jetson-io/jetson-io.pySelect Configure 40-pin expansion header at the bottom.
Select spi1 (19, 21, 23, 24, 26) and then select Back
Finally select Save and reboot to reconfigure pins. This will create a config file and reboot the Jetson Nano.
After the Nano boots up again, verify you have the I2C devices with the command:
ls /dev/i2c* /dev/spi*You can test to see what I2C addresses are connected by running
sudo i2cdetect -r -y 0(on pins 27/28) orsudo i2cdetect -r -y 1(on pins 3/5)Then, we need to set user permissions. In order to use the Jetson GPIO Library, the correct user permissions/groups must be set first. Start by creating a new gpio user group:
sudo groupadd -f -r gpiosudo usermod -a -G gpioClone the Repo and copy the rules:
cd ~git clone https://github.com/NVIDIA/jetson-gpio.gitsudo cp ~/jetson-gpio/lib/python/Jetson/GPIO/99-gpio.rules /etc/udev/rules.dThis section was originally written for releases before JetPack 4.3. For JetPack 4.3, the udev rules are in: /lib/udev/rulesd/60-jetson-gpio-common.rules. This should mean that you don’t have to copy the file anymore with JetPack 4.3 and above.
Also, it appears as if the default is for users to be included in the gpio group. You can check this by:
$ groupsReboot
Update just in case if a library is missing:
sudo pip3 install --upgrade adafruit_blinkaInstall CircuitPython NeoPixel_SPI library;:
pip3 install adafruit-circuitpython-neopixel-spiReboot again and that´s all!!!
Connect "Din" of your Neopixel to the SPI1_MOSI pin of your Jetson Nano(pin 19 of the expansion header), Gnd to Gnd and 5v to 5v.
try this example:
import boardimport neopixel_spipixels = neopixel_spi.NeoPixel_SPI(board.SPI(), 10)pixels.fill(0xff0000)If an error occurs Check you have installed this dependencies:
Adafruit CircuitPython BusDevice
pip3 install adafruit-circuitpython-busdevicePypixelbuf
pip3 install adafruit-circuitpython-pypixelbufInstall nano (just in case the nano editor is not installed)
sudo apt-get install nanoYou can check the Hex colors to use whatever colour you want by using this web page: https://www.color-hex.com/