SharpCoder

Bit Smoosher

This algorithm will take a 10/12/14 bit word and distribute it among 2 8-bit words. But in a lossless, efficient way. Why might someone want this? Well, it lets you stream uniquely sized words over 8-bit serial. That's why I need it anyway. Here's an example:

Suppose you have an 8-bit serial port and you want to stream 12-bit audio at 8kHz. Well, serial is typically maxing out around 115200 bits/s. You can't just use 2 bytes per datapoint, because you'll generate too much content. In order to solve

SharpCoder

$fn=100;

mount_base_w = 32.4;
mount_top_w = 23.8;
mount_depth = 10.0;

splitter_stem = 7;
splitter_height = 30;
platform_length = 45;
platform_angle = 22.5;

SharpCoder

@font-face {
  font-family: 'Roboto-Regular';
  font-style: normal;
  font-weight: 400;
  src: url('/custom/fonts/Roboto-Regular.woff2') format('woff2');
}

:root {
    --main-bg:         var(--white);
    --main-text:       #000;

SharpCoder

pub fn interpolate(start: u32, end: u32, elapsed: u64, duration: u64) -> u32 {
    // Calculate step
    let x0 = 0f32;
    let y0 = min(start, end) as f32;
    let x1 = duration as f32;
    let y1 = max(end, start) as f32;
    let x = min(elapsed, duration) as f32;
    let delta = (x  * ((y1 - y0)/(x1 - x0))) as u32;
    if start > end {
        return start - delta;

SharpCoder

pub fn get_color(&mut self, time: u64) -> Color {
    // Take the current time we are interested in (typically
    // system uptime in milliseconds) and modulus it by
    // the total time of our gradient so we end up with
    // a point between 0 and the total_time.
    let normalized_time = time % self.total_time;
    // The internal representation for this builder pattern
    // is a linked-list, so do some sanity checks.
    if self.root.is_none() {
        return self.color;

SharpCoder

This is how I wire up an ESP8266 and the power-on sequence I use to initialize the device.
It seems really hard to find such simple information, so here it is in this gist for all eternity.

------

VCC - 3.3v
GND - Gnd
RST - High
En  - High
Rx  - Tx

SharpCoder

#!/usr/bin/env bash

{ # this ensures the entire script is downloaded #

nvm_has() {
  type "$1" > /dev/null 2>&1
}

nvm_install_dir() {
  command printf %s "${NVM_DIR:-"$HOME/.nvm"}"

SharpCoder

Algorithm

There is surprisingly very little information about what the actual IARR algorithm is. IARR stands for Internal Average Relative Reflectance and the idea is that you extract the spectral information from the raw data by measuring the mean spectrum of the whole image. Every pixel vector is normalised by this global spectral mean to produce a 'relative reflectance' image. The psuedo-code for this algorithm is as follows:

for each band
   compute mean
for each pixel in a particular bad
   divide by the computed mean for this band

SharpCoder

#include "compass.h"

// COMPASS_MULTIPLIERS are calibrated per sensor and require an rigorous
// test environment. See README.md for more information.
int16_t COMPASS_MULTIPLIERS[360] = { 
  -213, -215, -213, -213, -213, -211, -208, -208, -204, -208, -206, -204, -204, -202, -200, -200, -200, -200, -202, -196, -196, -196, -196, -196, -196, -196, -192, -196, -192, -192, -192, -192, -192, -190, -189, -189, -189, -189, -189, -189, -189, -189, -189, -189, -187, -188, -185, -189, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -185, -189, -185, -185, -185, -185, -185, -185, -185, -185, -189, -189, -187, -189, -185, -189, -189, -189, -189, -189, -192, -189, -190, -190, -190, -192, -192, -192, -192, -192, -196, -192, -196, -196, -196, -196, -196, -196, -196, -196, -200, -200, -200, -196, -200, -200, -200, -201, -204, -204, -200, -204, -204, -204, -204, -204, -204, -208, -208, -208, -208, -213, -213, -208, -208, -208, -208, -213, -213

SharpCoder

use std::fs;
use std::path::Path;

pub trait Cache {
    fn write_file(&self, bucket: String, path: String, contents: String);
    fn write_json<Z : serde::ser::Serialize >(&self, bucket: String, path: String, model: Z);
    fn read_file(&self, bucket: String, path: String) -> Option<Vec<u8>>;
    fn read_json<Z : serde::de::DeserializeOwned>(&self, bucket: String, path: String) -> Option<Z>;
}