Skip to content

Instantly share code, notes, and snippets.

View multivac61's full-sized avatar
🎯
Focusing

multivac61 multivac61

🎯
Focusing
View GitHub Profile
@gocarlos
gocarlos / Eigen Cheat sheet
Last active February 11, 2024 14:07
Cheat sheet for the linear algebra library Eigen: http://eigen.tuxfamily.org/
// A simple quickref for Eigen. Add anything that's missing.
// Main author: Keir Mierle
#include <Eigen/Dense>
Matrix<double, 3, 3> A; // Fixed rows and cols. Same as Matrix3d.
Matrix<double, 3, Dynamic> B; // Fixed rows, dynamic cols.
Matrix<double, Dynamic, Dynamic> C; // Full dynamic. Same as MatrixXd.
Matrix<double, 3, 3, RowMajor> E; // Row major; default is column-major.
Matrix3f P, Q, R; // 3x3 float matrix.

BLE Nano and the nRF51822 SDK

If you've tried using the nRF51822 SDK with the BLE Nano (after following the RedBearLab guide) you may have come to a dead end.

Even the simplest examples didn't work for me. I assumed I had a dead Nano (despite the upload process seeming to work fine).

The reason turned out to be that the latest SDK versions assume you have a nRF51822 chip with 32KB of RAM rather than the 16KB that the nRF51822 on the Nano has.

James Willcox explains this in a post to the RedBearLab BLE Nano support forum.

@andreyvit
andreyvit / tmux.md
Created June 13, 2012 03:41
tmux cheatsheet

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

@rocarvaj
rocarvaj / .vimrc
Created April 27, 2012 21:28
Minimal .vimrc for C/C++ developers
" VIM Configuration File
" Description: Optimized for C/C++ development, but useful also for other things.
" Author: Gerhard Gappmeier
"
" set UTF-8 encoding
set enc=utf-8
set fenc=utf-8
set termencoding=utf-8
" disable vi compatibility (emulation of old bugs)
@endolith
endolith / frequency_estimator.py
Last active October 30, 2023 18:08
Frequency estimation methods in Python
from __future__ import division
from numpy.fft import rfft
from numpy import argmax, mean, diff, log, nonzero
from scipy.signal import blackmanharris, correlate
from time import time
import sys
try:
import soundfile as sf
except ImportError:
from scikits.audiolab import flacread