Category Archives: Development

Apple Product Ranges and Processor Architectures (Updated)

The iMac joins the Mac Mini as the only products to span three architectures

Apple Product Ranges and Processor Architectures

At the moment, the Mac Mini is unique in that it spans three processor architectures (although this is very likely to be matched by the iMac).

My Pebble Watchface – gWatch

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After some trial and error (and leaning heavily on the tutorials and sample code available online) I have built a Pebble watchface (named gWatch for obvious and boring reasons). It’s fairly basic – see the screenshot below.

Pebble Development in 2020

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After a fair amount of trial and error I now have the Pebble SDK working on my Mac (macOS 10.15.4 Catalina). I was working from the guide here. I can now create, build and deploy programs and watch faces to my Pebble watch.

Firstly I had problems with the virtualenv command:

cd ~/pebble-dev/pebble-sdk-4.3-mac
virtualenv --no-site-packages .env
source .env/bin/activate
CFLAGS="" pip install -r requirements.txt
deactivate

It turns out the –no-site-packages flag is not required and should be omitted (see here for details).

I then had issues with no SDK being installed (and the scripts trying in vain to locate the SDK on the Internet). After trying:

pebble new-project testing

I was greeted with:

No SDK installed; installing the latest one...

Consulting Google yielded:

Cannot install SDK from pebbledevelopers

The key part of the reddit post is path to the SDK. I used the following to successfully install the SDK:

pebble sdk install https://github.com/aveao/PebbleArchive/raw/master/SDKCores/sdk-core-4.3.tar.bz2

The last fix was disabling the analytics tracking by creating a NO_TRACKING file in the SDK directory.

SDK Install Guide from pebble

TempMonHTTP

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For a while I’ve been tinkering around with a simple project – an Arduino-based temperature (and humidity) monitor that outputs a webpage on my home LAN. The Arduino I used was the Freetronics EtherTen, a quality product.

Screenshot of the TempMonHTTP webpage. Yes, it gets hot in my walk in robe where the home LAN switch is…

Check out the code at https://github.com/gjhmac/TempMonHTTP.

Arduinos and SD cards

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If you require an SD card interface for your Arduino project I highly recommend purchasing an Arduino with one built-in. It took three attempts to get an SD card interface added to my basic Arduino Mega:

A very cheap generic (“LC Studio”) break out module that seemed to work intermittently at best;
A cheap shield (linksprite SD Card Shield v1.0b) – not compatible with the Mega (it does not state this on the packaging but if you search the documentation on their website it clearly states this, I should have done my research first);
And finally, a not so cheap Ethernet plus SD card shield (Freetronics) that worked without a hitch.

I would have been better off spending the extra coin on a Mega with the SD card interface built-in and reclaiming most of my weekend…

Rebble?

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Just found this:

http://rebble.io

Is there life left in my Pebble smartwatches still?

Edit: Maybe not. Sadly, the hardware seems to be failing. I’m seeing lots of intermittent issues with the LCD screen.

[Part 7] Arduino Data Logger

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// ————————————————————————————————————————————————
// Project: DataLogger
// Version: 0.4
// Date: 26 August 2018
// Author: Greg Howell <gjhmac@gmail.com>
// ————————————————————————————————————————————————
// Version Date Comments
// 0.4 26 August 2018 Modified code to only log to the SD card if the new value is different to the old value
// 0.3 30 June 2018 Added debugging and diagnostics on serial port, sped up ADC for analogue read (128kHz -> 1MHz), fixed “A REF”
// 0.2 26 April 2018 Addition of switch to enable/disable logging to SD card and LED to indicate logging status
// 0.1 17 February 2018 Initial Development
//
// ————————————————————————————————————————————————
// Description:
// – Logs analog0 value to a text file on the SD card along with date/time stamp in CSV format
// – Maintains date/time via DS1302 Real Time Clock
// – Builds with Arduino 1.8.5
// ————————————————————————————————————————————————

// #includes
#include <SPI.h> // Serial Peripheral Interface
#include <SD.h> // SD Cards
#include <DS1302.h> // DS1302 RTC

const int chipSelect = 4;
const int buttonPin = 5; // Pin 5 is the button to enable/disable logging (digital input)
const int ledPin = 6; // Pin 6 is the LED indicate logging status (digital output)

const byte PS_128 = (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);
const byte PS_16 = (1 << ADPS2);

int buttonState = 0; // initialise button state to off
int oldsensor; // variable to store the previous sensor value (used in loop())

// Init the DS1302
// Pin 2 = RST
// Pin 3 = DAT
// Pin 4 = CLK
DS1302 rtc(2, 3, 4);
// ————————————————————————————————————————————————
// setup()
// ————————————————————————————————————————————————
void setup() {

ADCSRA &= ~PS_128; // remove prescale of 128
ADCSRA |= PS_16; // add prescale of 16 (1MHz)

analogReference(EXTERNAL); // Analogue reference set to “A REF” pin

pinMode(buttonPin, INPUT); // Initialize the pushbutton pin as an input
pinMode(ledPin, OUTPUT); // Initialize the LED pin as an output

rtc.halt(false); // Set the clock to run-mode
rtc.writeProtect(false); // and disable the write protection

Serial.begin(9600);

// Use following lines once to set clock if battery fails (modify to suit)
//rtc.setDOW(SUNDAY); // Set Day-of-Week to FRIDAY
//rtc.setTime(21, 50, 0); // Set the time to 12:00:00 (24hr format)
//rtc.setDate(26, 8, 2018); // Set the date to August 6th, 2010

while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}

// Print current system date from RTC at start up
Serial.print(“System date: “);
Serial.println(String(rtc.getDateStr()) + “,” + String(rtc.getTimeStr()));

Serial.print(“Initializing SD card…”);

// see if the card is present and can be initialized:
if (!SD.begin(chipSelect)) {
Serial.println(“Card failed, or not present”);
// don’t do anything more:
while (1);
}
Serial.println(“card initialized.”);
}
// ————————————————————————————————————————————————
// loop()
// ————————————————————————————————————————————————
void loop() {
String dataString = “”; // make a string for assembling the data to log
int sensor = analogRead(A0); // read analogue
dataString += String(sensor); // construct string with analogue signal
buttonState = digitalRead(buttonPin); // read button state

// Logging enabled
if (buttonState == HIGH) {
File dataFile = SD.open(“datalog.txt”, FILE_WRITE);

// if the file is available, write to it
if (dataFile) {

// if the new data is different to the old data write it to file
if (sensor != oldsensor) {
// Write data to serial output
Serial.println(String(rtc.getDateStr()) + “,” + String(rtc.getTimeStr()) + “,” + dataString);
Serial.println(String(sensor) + “,” + String(oldsensor));
// Write data to SD card
dataFile.println(String(rtc.getDateStr()) + “,” + String(rtc.getTimeStr()) + “,” + dataString);
dataFile.close();
}
else {
dataFile.close();
}
// set logging LED to high
digitalWrite(ledPin, HIGH);
}
// if the file isn’t open, print an error
else {
digitalWrite(ledPin, LOW);
Serial.println(“error opening datalog.txt”);
}
}
// Logging disabled
else {
// set logging LED to low
digitalWrite(ledPin, LOW);
}
// set the old sensor value to the current sensor value (read at top of loop())
oldsensor = sensor;
// Wait before repeating 🙂
delay (500);
}

[Part 6] Arduino Data Logger

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// ————————————————————————————————————————————————
// Project: DataLogger
// Version: 0.3
// Date: 30 June 2018
// Author: Greg Howell
// ————————————————————————————————————————————————
// Version Date Comments
// 0.3 30 June 2018 Added debugging and diagnostics on serial port, sped up ADC for analogue read (128kHz -> 1MHz), fixed “A REF”
// 0.2 26 April 2018 Addition of switch to enable/disable logging to SD card and LED to indicate logging status
// 0.1 17 February 2018 Initial Development
//
// ————————————————————————————————————————————————
// Description:
// – Logs analog0 value to a text file on the SD card along with date/time stamp in CSV format
// – Maintains date/time via DS1302 Real Time Clock
// – Builds with Arduino 1.8.5
// ————————————————————————————————————————————————

// #includes
#include // Serial Peripheral Interface
#include // SD Cards
#include // DS1302 RTC

const int chipSelect = 4;
const int buttonPin = 5; // Pin 5 is the button to enable/disable logging (digital input)
const int ledPin = 6; // Pin 6 is the LED indicate logging status (digital output)

const byte PS_128 = (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);
const byte PS_16 = (1 << ADPS2);

int buttonState = 0; // initialise button state to off

// Init the DS1302
// Pin 2 = RST
// Pin 3 = DAT
// Pin 4 = CLK
DS1302 rtc(2, 3, 4);
// ————————————————————————————————————————————————
// setup()
// ————————————————————————————————————————————————
void setup() {

ADCSRA &= ~PS_128; // remove prescale of 128
ADCSRA |= PS_16; // add prescale of 16 (1MHz)

analogReference(EXTERNAL); // Analogue reference set to “A REF” pin

pinMode(buttonPin, INPUT); // Initialize the pushbutton pin as an input
pinMode(ledPin, OUTPUT); // Initialize the LED pin as an output

rtc.halt(false); // Set the clock to run-mode
rtc.writeProtect(false); // and disable the write protection

Serial.begin(9600);

// Use following lines once to set clock if battery fails (modify to suit)
//rtc.setDOW(THURSDAY); // Set Day-of-Week to FRIDAY
//rtc.setTime(15, 50, 0); // Set the time to 12:00:00 (24hr format)
//rtc.setDate(26, 4, 2018); // Set the date to August 6th, 2010

while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}

// Print current system date from RTC at start up
Serial.print(“System date: “);
Serial.println(String(rtc.getDateStr()) + “,” + String(rtc.getTimeStr()));

Serial.print(“Initializing SD card…”);

// see if the card is present and can be initialized:
if (!SD.begin(chipSelect)) {
Serial.println(“Card failed, or not present”);
// don’t do anything more:
while (1);
}
Serial.println(“card initialized.”);
}
// ————————————————————————————————————————————————
// loop()
// ————————————————————————————————————————————————
void loop() {
String dataString = “”; // make a string for assembling the data to log
int sensor = analogRead(A0); // read analogue
dataString += String(sensor); // construct string with analogue signal
buttonState = digitalRead(buttonPin); // read button state

// Logging enabled
if (buttonState == HIGH) {
File dataFile = SD.open(“datalog.txt”, FILE_WRITE);

// if the file is available, write to it:
if (dataFile) {
// Write data to serial output
Serial.println(String(rtc.getDateStr()) + “,” + String(rtc.getTimeStr()) + “,” + dataString);
// Write data to SD card
dataFile.println(String(rtc.getDateStr()) + “,” + String(rtc.getTimeStr()) + “,” + dataString);
dataFile.close();
digitalWrite(ledPin, HIGH);
}
// if the file isn’t open, pop up an error:
else {
digitalWrite(ledPin, LOW);
Serial.println(“error opening datalog.txt”);
}
}
// Logging disabled
else {
digitalWrite(ledPin, LOW);
}

// Wait before repeating 🙂
delay (200);
}