Chris' Blog.

My occasional thoughts on iOS development, developers careers, trying to make an income from the App Store, and updates on life in general.

Chalkinator Prototype

Would you be interested in me creating a native (macOS maybe?) desktop app that would manage your blog, geared at developers? I’ve been struck by how, over the years, I’ve had so many great work opportunities that have come my way through tech blogging, and how so few developers do it - surely they should, and if it was easier, maybe they would?

Please let me know, I really want to know if it’s worth investing time and effort into this, if it seems like an idea that could help people or if it would just be a waste of time and effort.

So I’ve created a prototype (the screenshot was above) for what I’d like to call ‘Chalkinator’. Basically with it you’d set up your site, choose your template, manage your posts, and voila you have a tech blog.

  • It would manage the hassles of organising your AWS/Cloudflare hosting so your blog would basically cost zero to run (unlike say Wordpress where reputable hosting costs a bit for a hobby blog), and wouldn’t slow down under load.
  • It wouldn’t be complicated like using Jekyll or Hugo or managing AWS hosting yourself, because I don’t think many people have endless hours they can waste getting their blog working.
  • I’ve used plenty of blogging platforms over the years. And when I’ve blogged for over 10 years it has become apparent that you need something that’ll stick around, otherwise you face painful migrations every few years. This is why I’d charge monthly instead of one-off, this is a win-win for customers and me: Customers get an app maintained in perpetuity, and I get to pay my bills in perpetuity.
  • It wouldn’t necessarily be only for developers, but it would be geared that way.
  • Code highlighting would ‘just work’ out of the box without any plugins. I imagine you’d write in Markdown and certain indents would automatically be treated as code.
  • macOS native perhaps, or maybe cross-platform - I’m not 100% clear on what would be best here to be honest, and would love to hear your suggestions.

So what’s with the bizarre name? Well, the thesaurus came up with ‘chalk’ as a synonym for write; my kids love watching ‘Odd Squad’ where agents use their gadgets to solve all sorts of weird problems, and all the gadgets end with ‘inator’… and so, this crazy portmanteau was born :)

Anyway I repeat, please let me know if this is a good idea or not. You can get in touch at [email protected] Thanks for reading :)


Flare

Over the years, various syncing applications have bugged me with how often they spike to 100% CPU usage, their memory usage, pricing, and other issues. So I set out to write my own for fun! Spoiler: in the end, I learned you really should just use Dropbox 🤣 However, I did manage to make it work, and reliably enough that I’m using it for some personal files, so I’m open-sourcing it in case anyone wants to check it out.

Flare

The project is called Flare, which is in reference to the ‘blaze’ part of the backend service’s name.

It is essentially a Dropbox clone that performs 2-way sync of files between a local folder and ‘the cloud’ (in this case, Backblaze B2). These files will then sync to many computers automatically. You could use it to keep a folder synced for members of a team, for instance. And because it uses Backblaze, your storage costs are miniscule.

It’s written in Swift, available at github.com/chrishulbert/flare, and (more-or-less) works!

You really shouldn’t use this for important use, it’s a hobby project!

Features

  • Uses zero CPU/RAM at idle because it only syncs hourly (and upon wake from sleep), and has no process running the rest of the time.
  • Even when running, uses little CPU/RAM due to simplicity and native code.
  • Syncs to Backblaze B2, which has extremely generous free tier and inexpensive pricing: If you used Flare and could live with its limitations, you could theoretically save a bucketload vs an office of people paying for a popular sync service.
  • If you delete a file, it will remain accessible in the Backblaze B2 admin panel for the duration of their garbage collection period (a week or a month, potentially).

Limitations

  • Both macOS and Windows (probably Linux too, I didn’t check) do not update the ‘last modified’ date of the tree of folders above a modified file. Eg, say you have a structure similar to foo/bar/yada/blah.txt and modify blah.txt. Foo, bar, and yada’s last modified date will unfortunately not change. In a slightly better case, if you rename blah.txt to blah2.txt, the immediate parent folder (yada) will change it’s last modified date, however grandparents and great-grandparents (foo and bar, respectively) will not. This is because those operating systems want to remain efficient. However this means that Flare cannot simply look at a last modified date and determine that it can skip an entire folder tree: it must still scan every subfolder and every file to see if anything has changed, every time it syncs. This is the biggest limitation of Flare. This could be resolved with an always-running agent, but then you’d also need a full-scan when launching the agent to catch any changes that occurred while it wasn’t running. However, for a hobby project I simply do not have the time to pursue this (I have children to chase!). Also, B2 does not give you folder last modified dates either, so you’d need a custom backend.
  • Flare handles subfolders very poorly. If you create a subfolder, it will sync fine. But if you delete that subfolder, it won’t have the smarts to know to ‘push’ that deletion to the server and ‘pull’ it down and apply it to other computers. IIRC this was due to the lack of metadata that could be reasonably stored with B2, which is totally understandable from their perspective. I really pushed B2 too far with all this.
  • Renames count as a deletion of the old file, and creation of a new file.
  • Huge files are simply thrown in the too-hard basket and ignored.
  • The macOS service that it used to schedule it is flaky: It launches Flare on wake from sleep only about half the time.
  • In general: What this project taught me is that 2-way sync is an exponentially more complicated problem than 1-way sync (although not an impossible problem: I got reasonably close to a useful solution!) and you should use one of the popular services for anything important, and be amazed when they ‘just work’.

Installation

These instructions are only for macOS. However, the app should compile fine on any Swift-supported platform if you see fit.

  • Create a Backblaze B2 account and bucket.
  • Install homebrew if needed: brew.sh
  • Install flare: brew install chrishulbert/flare/flare
  • Configure it: flare configure
  • Schedule it to run hourly: flare schedule

Musings

Swift really won me over with it’s ability to model all the edge-cases of synchronisation in a way that wouldn’t compile unless I handled every one. A great example of this is the switch statement in ListingReconciliation.swift. This is how a good language fosters safe code, and I’m a huge fan. So: thanks, Chris Lattner.

Thanks for reading, I hope this interests someone, and have a great week!

Legals: I take no responsibility; give no guarantee/warranty for this project.

Photo by Christopher Cambpell via Unsplash


Baby Monitor

I’ve been struck by how many baby monitors have died over the span of our children. The things just seem to last about a year or two, and they cost a lot! So I’ve finally decided to make my own.

Hardware

I’m using a pair of ESP32 boards here, because they’re popular, common, and cheap. They have ESP-Now which allows you to communicate between them without Wi-Fi, an I2S audio input, and a DAC for audio output. You should be able to find them on ebay for under $10 each.

For the microphone, I’m using an INMP441. It’s a 24-bit I2S non-PDM microphone which is, you guessed it, cheap. You should be able to find them for under $5 on ebay.

The speaker I used is an 8Ω one I had lying around in a learn electronics kit. It’s very quiet. If you were doing this project for real, you should probably find a small amplifier board instead.

Microphone wiring

To connect the microphone to one of the ESP32s, I recommend reading about I2S on Wikipedia first. Here’s the connections:

  • L/R (left/right) -> This goes to ground. According to the INMP441 datasheet this makes it the left channel.
  • WS (word select, aka LRCLK) -> This goes to pin D15 on the ESP32.
  • SCK (serial clock, aka BCLK/bit clock) -> D14.
  • SD (serial data, aka DOUT) -> D34.
  • VDD -> To +3.3V.
  • GND -> Ground.

Speaker wiring

To connect the speaker (or line-out) to the other ESP32:

  • One wire to ground.
  • Another wire to D25 on the ESP32.

Arduino

I’m using Arduino to program the ESP32s, because it’s simpler than Espressif’s toolchain. Install Arduino, then follow these instructions to add ESP32 support.

You’ll probably need to install drivers to suit whatever USB-UART bridge chip is on your boards. There should be two chips near the USB connector: one is power (not many pins), and one is the UART (lots of pins). Read the chip number, find the manufacturer’s page, and find and install the drivers. In my case, it was a Silabs CP2102.

The Arduino settings that work for me are as follows, perhaps they will work for you:

  • Tools > Board > ESP32 Wrover module
  • Tools > Port > /dev/cu.SLAB_USBtoUART
  • Tools > Programmer > ArduinoISP

I find that I need to hold down the ‘boot’ button on my boards while programming them.

ESP-Now setup

You’ll need to find the MAC of the receiving ESP32. Here’s some Arduino code to do this:

#include "WiFi.h"

void setup() {
    Serial.begin(115200);
    WiFi.mode(WIFI_MODE_STA);
    Serial.println(WiFi.macAddress());
}

void loop() {}

Transmitter

Here’s the code for the ESP32 which listens to the mic via the I2S input, converts to 8-bits, and transmits over ESP-Now:

#include "WiFi.h"
#include "esp_now.h"
#include "driver/i2s.h"

uint8_t receiverMAC[] = {0x11, 0x22, 0x33, 0x44, 0x55, 0x66}; <- Replace this with the MAC of your other board!

void setup() {
    Serial.begin(115200);
    
    WiFi.mode(WIFI_MODE_STA); // Wifi (prerequisite for ESP-Now).

    // Setup ESP-Now first, because I2S uses it.
    Serial.println("Setup ESP-Now...");
    if (ESP_OK != esp_now_init()) {
        Serial.println("esp_now_init: error");
        return;
    }
    esp_now_peer_info_t peerInfo = {0};
    memcpy(peerInfo.peer_addr, receiverMAC, sizeof(receiverMAC));
    // TODO encrypt, by setting peerInfo.lmk.
    if (ESP_OK != esp_now_add_peer(&peerInfo)) {
        Serial.println("esp_now_add_peer: error");
        return;
    }

    // I2S.
    Serial.println("Setup I2S...");
    i2s_config_t i2s_config = {
        .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
        .sample_rate = 11025,
        .bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT, // INMP441 is 24 bits, but it doesn't work if we set 24 bit here.
        .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
        .communication_format = i2s_comm_format_t(I2S_COMM_FORMAT_I2S | I2S_COMM_FORMAT_I2S_MSB),
        .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
        .dma_buf_count = 4,
        .dma_buf_len = ESP_NOW_MAX_DATA_LEN * 4, // * 4 for 32 bit.
        .use_apll = false,
        .tx_desc_auto_clear = false,
        .fixed_mclk = 0,
    };
    if (ESP_OK != i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL)) {
        Serial.println("i2s_driver_install: error");
    }
    i2s_pin_config_t pin_config = {
        .bck_io_num = 14,   // Bit Clock.
        .ws_io_num = 15,    // Word Select.
        .data_out_num = -1,
        .data_in_num = 34,  // Data-out of the mic.
    };
    if (ESP_OK != i2s_set_pin(I2S_NUM_0, &pin_config)) {
        Serial.println("i2s_set_pin: error");
    }
    i2s_zero_dma_buffer(I2S_NUM_0);

    Serial.println("Setup done.");
}

// This is used to scale the audio when things get loud, and gradually increase sensitivity when things go quiet.
#define RESTING_SCALE 127
int32_t scale = RESTING_SCALE;

void loop() {
    // Read from the DAC. This comes in as signed data with an extra byte.
    size_t bytesRead = 0;
    uint8_t buffer32[ESP_NOW_MAX_DATA_LEN * 4] = {0};
    i2s_read(I2S_NUM_0, &buffer32, sizeof(buffer32), &bytesRead, 1000);
    int samplesRead = bytesRead / 4;

    // Convert to 16-bit signed.
    // It's actually 24-bit, but the lowest byte is just noise, even in a quiet room.
    // If we go to 16 bit we don't have to worry about extending a sign byte.
    // Quiet room seems to be values maxing around 7.
    // Max seems around 300 with me at 0.5m distance talking at normal loudness.
    int16_t buffer16[ESP_NOW_MAX_DATA_LEN] = {0};
    for (int i=0; i<samplesRead; i++) {
        // Offset + 0 is always E0 or 00, regardless of the sign of the other bytes,
        // because our mic is only 24-bits, so discard it.
        // Offset + 1 is the LSB of the sample, but is just fuzz, discard it.
        uint8_t mid = buffer32[i * 4 + 2];
        uint8_t msb = buffer32[i * 4 + 3];
        uint16_t raw = (((uint32_t)msb) << 8) + ((uint32_t)mid);
        memcpy(&buffer16[i], &raw, sizeof(raw)); // Copy so sign bits aren't interfered.
    }

    // Find the maximum scale.
    int16_t max = 0;
    for (int i=0; i<samplesRead; i++) {
        int16_t val = buffer16[i];
        if (val < 0) { val = -val; }
        if (val > max) { max = val; }
    }

    // Push up the scale if volume went up.
    if (max > scale) { scale = max; }
    // Gradually drop the scale when things are quiet.
    if (max < scale && scale > RESTING_SCALE) { scale -= 300; }
    if (scale < RESTING_SCALE) { scale = RESTING_SCALE; } // Dropped too far.

    // Scale it to int8s so we aren't transmitting too much data.
    int8_t buffer8[ESP_NOW_MAX_DATA_LEN] = {0};
    for (int i=0; i<samplesRead; i++) {
        int32_t scaled = ((int32_t)buffer16[i]) * 127 / scale;
        if (scaled <= -127) {
            buffer8[i] = -127;
        } else if (scaled >= 127) {
            buffer8[i] = 127;
        } else {
            buffer8[i] = scaled;
        }
    }

    // Send to the other ESP32.
    if (ESP_OK != esp_now_send(NULL, (uint8_t *)buffer8, samplesRead)) {
        Serial.println("Error: esp_now_send");
        delay(500);
    }
}

Receiver

#include "WiFi.h"
#include "esp_now.h"
#include "driver/i2s.h"

// Called when ESP-Now receives.
void onDataRecv(const uint8_t *mac, const uint8_t *incomingRaw, int samples) {
    // Convert it from 8 bit signed to 16 bit unsigned with an 0x80 delta which is what the DAC requires.
    int8_t *incoming8 = (int8_t *)incomingRaw;
    uint16_t incoming16[ESP_NOW_MAX_DATA_LEN] = {0};
    for (int i=0; i<samples; i++) {
        int32_t value = incoming8[i];
        value += 0x80; // DAC wants unsigned values with a bias, not signed!
        incoming16[i] = value << 8;
    }

    // Forward it to the DAC.
    size_t bytesWritten=0;
    i2s_write(I2S_NUM_0, incoming16, samples * 2, &bytesWritten, 500);
}

void setup() {
    Serial.begin(115200);

    // Setup I2S first, because the ESP-Now listener uses it.
    i2s_config_t i2s_config = {
        .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN),
        .sample_rate = 11025
        .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
        .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
        .communication_format = I2S_COMM_FORMAT_I2S_MSB,
        .intr_alloc_flags = 0,
        .dma_buf_count = 4,
        .dma_buf_len = ESP_NOW_MAX_DATA_LEN * 2,
        .use_apll = false
    };
    i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
    i2s_zero_dma_buffer(I2S_NUM_0);
    i2s_set_pin(I2S_NUM_0, NULL);

    // ESP-Now.
    Serial.println("ESP-Now setup...");
    WiFi.mode(WIFI_STA);
    if (esp_now_init() != ESP_OK) {
        Serial.println("Setup > ESP-Now error");
        return;
    }
    esp_now_register_recv_cb(onDataRecv);

    Serial.println("Setup complete.");
}

void loop() {}

Etc

Things you might want to consider, because this project is far from perfect:

  • Using an ESP-Now encryption key.
  • Making the ‘sender’ not transmit a packet if the sound level is quiet, which will likely extend the life of the radio circuitry.
  • Making the ‘receiver’ handle missed packets gracefully and treat them as quiet.
  • Some kind of amplifier, or I2S sound output from the receiver, for better sound quality.
  • Mounting it nicely!

Thanks for reading, I hope this helps someone, and have a great week!

Legals: I take no responsibility; give no guarantee/warranty for this project.


You can see older posts in the right panel, under 'archive'.

Archive

Introducing Chalkinator: Native desktop blogging app 7 Jun 2020

Flare: Open source 2-way folder sync to Backblaze B2 in Swift 28 May 2020

Making a baby monitor out of a couple of ESP32s, an I2S microphone, and a small speaker 16 Apr 2020

Chris' 2020 guide to hosting a HTTPS static site on AWS S3 + Cloudfront 15 Mar 2020

Simple Javascript debounce, no libraries needed 20 Feb 2020

Asynchronous NSOperations in Swift 5 3 Jan 2020

Deploying Golang Revel sites to AWS Elastic Beanstalk 9 Dec 2019

Golang and pure Swift Compression and Decompression 28 Jul 2019

Pure Swift simple Keychain wrapper 23 Jun 2019

Pure Swift 5 CommonCrypto AES Encryption 9 Jun 2019

Bluetooth example code for Swift/iOS 6 Jun 2019

Talking to a Bluetooth LE peripheral with Swift/iOS 18 May 2019

Obfuscating Keys using Swift 5 May 2019

State Machines in Swift using enums 10 Apr 2019

iOS timers without circular references with Pendulum 28 Mar 2019

Pragmatic Reactive Programming 11 Oct 2017

React Native first impressions 7 Apr 2017

Gondola 26 Feb 2017

Scalable Swift 22 Nov 2016

Swift 3 Migration 6 Nov 2016

Enum-Driven View Controllers 3 Jan 2016

Status bar colours: Everything there is to know 30 Dec 2015

Android server 20 Dec 2015

Generating heightmap terrain with Swift 8 Nov 2015

Swift Education Screencasts 27 Oct 2015

Swift Image Cache 24 Sep 2015

Don't be slack 13 Sep 2015

Swift KVO alternative 23 Jul 2015

Swift Keychain wrapper 21 Jun 2015

Swift NSURLSession wrapper 12 Jun 2015

iOS8 View Controller transitioning bug 17 Apr 2015

IB Designable 18 Mar 2015

iOS App Architecture 2 Mar 2015

Video Course Launch 14 Feb 2015

Video Course Pre-launch 8 Feb 2015

Blogging Platforms 13 Jan 2015

Mobile in 2014 - Year in Review 11 Jan 2015

Secret Keys talk 16 Nov 2014

Dimmi 11 Nov 2014

Project setup in Xcode6 22 Oct 2014

Uploading to an S3 bucket from iOS 15 Oct 2014

iOS8 App Testing Roundup 28 Sep 2014

Storing obfuscated secret keys in your iOS app 16 Sep 2014

Getting Core Location / CLLocationManager to work on iOS8 14 Sep 2014

Accessing the response body in failure blocks with AFNetworking 2 10 Sep 2014

How to allow your UITextFields to scroll out of the way of the keyboard 8 Sep 2014

How to subclass UIButton in iOS7 and make a UIButtonTypeSystem 4 Sep 2014

New season 1 Aug 2014

House finished 17 Jun 2014

WebP decoding on iOS 9 Feb 2014

Moving on again 22 Jan 2014

Lossy images for retina iPads - JPEG vs WebP 30 Nov 2013

Career options I wish I knew about when I was younger 20 Oct 2013

Positivity and your friends 7 Oct 2013

Tactility 26 Jul 2013

WWDC-induced narcolepsy 15 Jul 2013

Back on rails 31 May 2013

Full circle 6 May 2013

Programmatic UI on iOS 3 May 2013

Screencasts and positivity 8 Apr 2013

Year of positivity 14 Mar 2013

iOS Dev State of the Union 6 Feb 2013

Adventures with IAPs 3 Feb 2013

No longer a Googler 23 Dec 2012

Localising iPhone apps with Microsoft Translator 8 Dec 2012

Fight back (app biz update 13) 12 Nov 2012

Sent to the backburner (app biz update 12) 25 Oct 2012

Lisi Schappi 7 Oct 2012

Today's happy plateau (app biz update 11) 26 Aug 2012

First week's sales of Today (app biz update 10) 19 Aug 2012

Today launch! And a difficult decision made... (app biz update 9) 15 Aug 2012

Approved! (app biz update 8) 5 Aug 2012

Creating a graph in Objective-C on the iPhone 3 Aug 2012

Hurry up and wait (app biz update 7) 30 Jul 2012

Today app marketing site 27 Jul 2012

Today app submitted 25 Jul 2012

UIAlertView input wrapper 24 Jul 2012

Mentoring 23 Jul 2012

This is too hard! (app biz update 6) 20 Jul 2012

Perspectives (app biz update 5) 9 Jul 2012

4th starting-my-own-biz update 1 Jul 2012

ScrumFox landing page 28 Jun 2012

Server Scope landing page 27 Jun 2012

Telstra Calls and Data Usage 26 Jun 2012

Service History + Dropbox 26 Jun 2012

Impromptu Presenter 26 Jun 2012

Fertility Tracker 26 Jun 2012

Baby Allergy Tracker 26 Jun 2012

Starting my own business, update 3 22 Jun 2012

Starting my own business, update 2 17 Jun 2012

Starting my own business - First update 10 Jun 2012

I must be crazy 6 Jun 2012

Finding your location on an iPhone 7 May 2012

A generous career 4 May 2012

Skeleton Key Cocoaheads presentation 3 May 2012

CHBgDropboxSync - Dropbox auto-sync for your iOS apps 1 May 2012

That book about that Steve Jobs guy 30 Apr 2012

Another app marketing idea 23 Apr 2012

Sweet grouped tables on the iPhone 17 Apr 2012

Skeleton Key App 11 Apr 2012

Another app marketing idea... 5 Apr 2012

Quickly check for any missing retina graphics in your project 3 Apr 2012

Skeleton Key Password Manager with Dropbox 2 Apr 2012

RC Boat motor finally mounted 2 Apr 2012

Promoting apps presentation slides 1 Apr 2012

How i just wasted a month on my latest app, and how you don't need to 26 Mar 2012

The Finishing Line 20 Mar 2012

Using Launchd to run a script every 5 mins on a Mac 20 Feb 2012

Generating AES256 keys from a password/passphrase in ObjC 20 Feb 2012

Indie iPhone app marketing, part 2 19 Feb 2012

My App Manifesto: Syncing + Dropbox + YAML = Awesome 15 Feb 2012

Indie iPhone App Marketing part 1 7 Feb 2012

Perspectives 2 Feb 2012

Accountability and Free Will 1 Feb 2012

Badassery 31 Jan 2012

Sacrifice 30 Jan 2012

Lead Yourself First 29 Jan 2012

How to ping a server in Objective-C / iPhone 26 Jan 2012

iOS Automated Builds with Xcode4 16 Jan 2012

Xcode 4 - Command line builds of iPhone apps 15 Jan 2012

Guest post by Jason McDougall 13 Jan 2012

Scouts, Games and Motivation 10 Jan 2012

2011 Re-cap 8 Jan 2012

Ruby script to increment a build number 4 Jan 2012

Turning 30? All ideas, no execution? 18 Dec 2011

CHDropboxSync - simply sync your iOS app's documents to Dropbox 14 Dec 2011

Deep-enumerating a directory on the iphone, getting file attributes as you go 10 Dec 2011

Getting a date without the time component in objective-c 6 Dec 2011

Memory management in Objective-C 4 Dec 2011

Starting small 29 Nov 2011

Dictionary Types Helper 29 Nov 2011

Observer Pattern in Objective-C 16 Nov 2011

Why you should give presentations 13 Nov 2011

How to get a programming or design job in Sydney 9 Nov 2011

Custom nav bar / toolbar backgrounds in iOS5 8 Nov 2011

Stuck 27 Oct 2011

Dead easy singletons in Obj-C 19 Oct 2011

JSON vs OCON (Objective-C Object Notation) 18 Oct 2011

In defence of Objective-C 16 Oct 2011

Update the MessagePack objective-c library to support packing 12 Oct 2011

Icons 11 Oct 2011

How to host a site on Amazon AWS S3, step-by-step 7 Oct 2011

Drawing a textured pattern over the default UINavigationBar 6 Oct 2011

Markdown Presentations 1 Oct 2011

More MegaComet testing: Ruling out keepalives 15 Sep 2011

MegaComet test #4 - This time with more kernel 14 Sep 2011

Building People 10 Sep 2011

Half way there: Getting MegaComet to 523,000 concurrent HTTP connections 5 Sep 2011

Making a progress bar in your iPhone UINavigationBar 22 Aug 2011

Hacker News Reader 20 Aug 2011

How to programmatically resize elements for landscape vs portrait in your iphone interface 16 Aug 2011

MegaComet testing part 2 3 Aug 2011

Australian Baby Colours 28 Jul 2011

Boat prop shaft 25 Jul 2011

Megacomet with 1 million queued messages 24 Jul 2011

Installed the strut and rudder 18 Jul 2011

Painted the inside of the boat 17 Jul 2011

Fuzzy iphone graphics when using an UIImageView set to UIViewContentModeCenter 13 Jul 2011

My 3 Data and Calls Usage 11 Jul 2011

Reading a line from the console in node.js 10 Jul 2011

Trim whitespaces on all text fields in a view controller 9 Jul 2011

Final finish 9 Jul 2011

MessagePack parser for Objective-C / iPhone 30 Jun 2011

Lacquering the starboard side 25 Jun 2011

What do do with EXC_ARM_DA_ALIGN on an iPhone app 23 Jun 2011

Lacquering the hull 23 Jun 2011

Staining the boat 22 Jun 2011

NSMutableSet with weak references in objective-c 20 Jun 2011

Iphone gesture recogniser that works for baby games 20 Jun 2011

Image manipulation pixel by pixel in objective C for the iphone 19 Jun 2011

Baby Allergy Tracker 12 Jun 2011

Power sanding the deck 10 Jun 2011

Planing the edge of the deck 2 Jun 2011

Figured out the deck 2 Jun 2011

Boat bulkheads 2 Jun 2011

Simulating iOS memory warnings 31 May 2011

Putting a UIButton in a UIToolbar 29 May 2011

How to allow closing a UIActionSheet by tapping outside it 29 May 2011

Finding the currently visible view in a UITabBarController 24 May 2011

Random Chef 17 May 2011

Centered UIButton in a navigation bar on the iphone 16 May 2011

Little Orchard 13 May 2011

Boat update 13 May 2011

How to get the current time in all time zones for the iphone / obj-c 12 May 2011

Design portfolio 10 May 2011

Tricks with grand central dispatch, such as objective-c's equivalent to setTimeout 9 May 2011

How to make an iphone view controller detect left or right swipes 5 May 2011

Centered section headers on a UITableView 5 May 2011

Christmas in may 4 May 2011

Finished trimming the boat (its floatable now!) and got some parts 29 Apr 2011

How to make a multiline label with dynamic text on the iphone and get the correct height 27 Apr 2011

Forcing an image size on the image in a table view cell on an iphone 20 Apr 2011

Git on the Mac 19 Apr 2011

Build a url query string in obj-c from a dictionary of params like jquery does 12 Apr 2011

Rendering a radial gradient on the iphone / objective-c 11 Apr 2011

Skinning the port side of the boat 8 Apr 2011

Skinning the side of the boat 5 Apr 2011

Sending a UDP broadcast packet in C / Objective-C 5 Apr 2011

How to talk to a unix socket / named pipe with python 4 Apr 2011

Skinning the bottom of the boat 31 Mar 2011

Service discovery using node.js and ssdp / universal plug n play 30 Mar 2011

Extremely simple python threading 29 Mar 2011

New rescue boat 26 Mar 2011

HttpContext vs HttpContextBase vs HttpContextWrapper 5 Nov 2010

Simple C# Wiki engine 30 Sep 2010

Simple way to throttle parts of your Asp.Net web app 29 Sep 2010

How to implement DES and Triple DES from scratch 4 Aug 2010

How to use sessions with Struts 2 30 Jul 2010

How to use Cookies in Struts 2 with ServletRequest and ServletResponse 30 Jul 2010

Using Quartz Scheduler in a Java web app (servlet) 27 Jul 2010

Javascript date picker that Doesn't Suck!(tm) 27 Jul 2010

Using Oracle XE with Hibernate 20 Jul 2010

A simple implementation of AES in Ruby from scratch 29 Jun 2010

Asp.Net Forms authentication to your own database 28 May 2010

AS2805 (like ISO8583) financial message parser in C# 7 May 2010

Ruby hex dumper 4 May 2010

Using Spring to manage Hibernate sessions in Struts2 (and other web frameworks) 13 Jan 2010

Emails in C#: Delivery and Read receipts / Attachments 12 Jan 2010

Using Java libraries in a C# app with IKVM 16 Dec 2009

Learning Java tutorial 27 Nov 2009

Using generic database providers with C# 17 Nov 2009

Scheduled task executable batch babysitter 29 Oct 2009

Working with query strings in Javascript using Prototype 30 Sep 2009

Still fighting with String.Format? 9 Sep 2009

How I'd build the next Google 24 Aug 2009

Getting IIS and Tomcat to play nicely with isapi_redirect 24 Aug 2009

Using the new ODP.Net to access Oracle from C# with simple deployment 11 Aug 2009

C# Cryptography - Encrypting a bunch of bytes 14 Jul 2009

Sorting enormous files using a C# external merge sort 10 Jul 2009

Reconciling/comparing huge data sets with C# 9 Jul 2009

Some keyboard-friendly DHTML tricks 10 Jun 2009

How to figure out what/who is connected to your SQL server 18 Mar 2009

Adding a column to a massive Sql server table 16 Mar 2009

Multithreading using Delegates in C# 10 Mar 2009

Using C# locks and threads to rip through a to-do list 6 Feb 2009

Using threads and lock in C# 3 Feb 2009

Compressing using the 7Zip LZMA algorithm in C# beats GZipStream 14 Jan 2009

MS Sql Server 2005 locking 17 Dec 2008

Simple Comet demo for Ruby on Rails 19 Nov 2008

Geocoding part 2 - Plotting postcodes onto a map of Australia with C# 24 Oct 2008

Using evolutionary algorithms to make a walkthrough for the light-bot game with C# 20 Oct 2008

How to tell when memory leaks are about to kill your Asp.Net application 16 Oct 2008

C# version of isxdigit - is a character a hex digit? 15 Sep 2008

Geocoding part 1 - Getting the longitude and latitude of all australian postcodes from google maps 26 Aug 2008

Converting HSV to RGB colour using C# 14 Aug 2008

Opening a TCP connection in C# with a custom timeout 11 Aug 2008

Oracle Explorer - a very simple C# open source Toad alternative 31 Jul 2008

Linking DigitalMars' D with a C library (Mongrel's HTTP parser) 23 Jun 2008

Connecting to Oracle from C# / Winforms / Asp.net without tnsnames.ora 16 Jun 2008

A simple server: DigitalMars' D + Libev 6 Jun 2008

Travelling from Rails 1 to Rails 2 9 Apr 2008

Online Rostering System 9 Apr 2008

DanceInforma 9 Apr 2008

Using RSS or Atom to keep an eye on your company's heartbeat 10 Nov 2007

Easy Integrated Active Directory Security in ASP.Net 24 Oct 2007