Sun 29 June 2014
My boss Mike has paid for a satellite phone for us so that we can contact people if we get into trouble.
The phone I bought at first had the capability to send periodic location updates to some third-party online services, however the supplier turned out to be out of stock and sent a refund.
I then bought an Iridium 9555.
In order to do online location tracking, I've made a small system consisting of:
The online map viewer is at http://jes.xxx/lush/. It loads the coordinates from a JSON file.
The HTTP interface takes a latitude, longitude and message and adds an entry to the JSON data.
The SMS interface works similarly, and uses a number bought for €0.50/mo from Nexmo.
The Android app is a simpler method of sending the SMS: instead of opening the SMS app and inputting coordinates copied from a GPS app, there is simply a button labelled "Send coordinates" which gets the current location from GPS and opens the SMS app with a message already filled in, and sending to the correct number.
This means we are able to send location updates via a wifi internet connection, a mobile internet connection, satellite internet connection, mobile SMS or satellite SMS. This should give us the ability to send location updates at any time of day or night.
I plan to add to the map viewer a list of recent times/messages down one side of the page, and make the HTTP interface for new coordinates use the HTML5 location API, and add a method to subscribe for (either instant or daily) location updates via email and/or SMS.If you like my blog, please consider subscribing to the RSS feed or the mailing list: