Vojtěch Vrba vrbadev

Installing ROS Noetic on Raspberry Pi 4

Hello Everyone. I've been trying to install ROS Noetic on Raspbian GNU/Linux 10 (buster) from source but it was like a nightmare. Finally, I was able to install it and I want to share it with you.

Steps:

$ sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

Enable camera module

Edit your /boot/config.txt file and make sure the following lines look like this:

start_x=1             # essential
gpu_mem=128           # at least, or maybe more if you wish
disable_camera_led=1  # optional, if you don't want the led to glow

Load bcm2835-v4l2 module

Normalize volume level with PulseAudio and simultaneous output

This should work conceptually on any Linux OS with PulseAudio but these particular instructions are for Ubuntu. There are two major reasons for using simultaneous output. The first is self-evident - we can output to say a bluetooth headset and wired headphones at the same time to enable two people to watch a movie with headphones on a single computer. The second reason is a sort of a convenience for setup. We know the simultaneous sink name so the default.pa config would work without modification so long as simultaneous output is enabled. If we were to set this up without that, we'd have to customize the config with our specific device sink name. That's totally doable but personally I always setup simultaneous output. That's why I haven't described the alternative in this gist.

I successfully created a project instantiating the HPS in Qsys. I added a parallel I/O in Qsys to allow the HPS to communicate with the LEDs via the HPS-to-FPGA lightweight bus. From there, I generated a preloader and U-boot along with the SOF file. I also wrote a simple C program that counts from 0-15 and sets the LEDs to that value every second. This encompasses about every step required to be able to communicate between the FPGA and HPS, so this is definitely a first step. I'm going to document what I did and how you guys can get this running.

I did this on Windows since that is my primary OS. Things are different on Linux, so you will have to figure them out if you try to do this on Linux.

File Structure

DE10NanoUART-FPGA

Project containing everything necessary to get exactly what I have running
HPS_FPGA_LED - Source code and makefile for the C program to blink LEDs
hps_isw_handoff - ISW stands for Initial SoftWare so it is the first thing to be ran AFTER the hardcoded bootrom is loa

How to make a debian from a ROS package

The instructions are based on this answers.ros.org thread.

Get dependencies

You may need the latest pip, follow the official instructions.

Install bloom:

Pico HTTP Server in C

This is a very simple HTTP server for Unix, using fork(). It's very easy to use

How to use

include header httpd.h
write your route method, handling requests.
call serve_forever("12913") to start serving on port 12913

	# https://superuser.com/a/1434648

	Add-Type -AssemblyName System.Runtime.WindowsRuntime
	$asTaskGeneric = ([System.WindowsRuntimeSystemExtensions].GetMethods() \| ? { $_.Name -eq 'AsTask' -and $_.GetParameters().Count -eq 1 -and $_.GetParameters()[0].ParameterType.Name -eq 'IAsyncOperation`1' })[0]

	Function Await($WinRtTask, $ResultType) {
	$asTask = $asTaskGeneric.MakeGenericMethod($ResultType)
	$netTask = $asTask.Invoke($null, @($WinRtTask))
	$netTask.Wait(-1) \| Out-Null
	$netTask.Result

	#' Wavelength to RGB
	#'
	#' This function converts a given wavelength of light to an
	#' approximate RGB color value.
	#'
	#' @param wavelength A wavelength value, in nanometers, in the human visual range from 380 nm through 750 nm.
	#' These correspond to frequencies in the range from 789 THz through 400 THz.
	#' @param gamma The \eqn{\gamma} correction for a given display device. The linear RGB values will require
	#' gamma correction if the display device has nonlinear response.
	#' @return a color string, corresponding to the result of \code{\link[grDevices]{rgb}} on the

	# curvefit with non linear least squares (curve_fit function)
	import numpy as np
	from scipy.optimize import curve_fit

	def func(x, a, b, c):
	return anp.sin(x[0])+bnp.cos(x[1])+c

	limits = [0, 2np.pi, 0, 2np.pi] # [x1_min, x1_max, x2_min, x2_max]
	side_x = np.linspace(limits[0], limits[1], 100)
	side_y = np.linspace(limits[2], limits[3], 100)

	Download Google Drive files with WGET

	Example Google Drive download link:

	https://docs.google.com/open?id=[ID]
	To download the file with WGET you need to use this link:

	https://googledrive.com/host/[ID]

	Example WGET command: