I had looked into panic buttons (small portable devices that send an SOS by SMS, for instance for elderly people who took a fall and need help) and they either seem to be rubbish, or come with a monthly or annual subscription service and thought: that should and could be done differently (and cheaper). It can be. It is.
The heart of the solution is the Puck.js (http://www.espruino.com/Puck.js), which is yours for about 30 GBP + shipping, in my case around 40 EUR. The solution itself consists of 2 components:
If the user presses the Puck’s button ‘x’ times within the configured time interval, the Puck will start broadcasting a 'panic' message and all of its LEDs will start flashing, telling the user that now a panic message is being broadcast, and the app will pick this message up and then send an SMS to the configured phone number; the default text (which can be changed in the preferences) is "I have pressed the PANIC button, please call me and if I don't pick up, please call emergency services". Once the user presses the button an additional time, the panic message is no longer broadcast; instead, a battery level message is sent out.
Caveats:
- For some reason - I don’t know why and it might be a mistake of mine, but this does the trick for me and I don’t intend to publish the app on Google Play so it’s irrelevant to me - in the Manifest, leave targetSDKversion to 14; with 26, the BLE stuff doesn't work.
- When 'scanning' is enabled, the app will consume more battery power as it will then use a partial lock to ensure the CPU stays alive even when the device is on lock screen (there’s no point in having a panic button that doesn’t do that).
- The Puck’s JavaScript code in the example is set to only count 500ms presses to avoid false positives (you may want to read - a lot - on the Espruino site to see what I mean). In other words, the user must press the Puck's button for half a second, 'x' times, within the configured interval.
Quick start guide:
- Install the JavaScript code on the Puck; modify it so that the 'puckname' variable has a value you will recognise. Modify other configurable values too, if desired.
- Install the app on the phone.
- Set the preferences in the app (see menu).
- In the 'Scan' menu, enable 'Show all'.
- Check out the BLE broadcasting devices that are shown in the CustomListview now, and tap your Puck, so that it will be saved as 'the relevant one'.
- Start scanning and hope the app will never send you an SMS.
Enjoy!
The heart of the solution is the Puck.js (http://www.espruino.com/Puck.js), which is yours for about 30 GBP + shipping, in my case around 40 EUR. The solution itself consists of 2 components:
- JavaScript code running on the Puck and (BLE) broadcasting either the Puck’s battery level (which also serves as a heartbeat) or a panic message, indicating that the user has clicked the Puck’s button a number of times (the number is set in the JavaScript code - all configurable values are set at the bottom of that code).
- An Android app that listens to BLE broadcasts and sends an SMS (e.g., to a friend or relative) when a panic message is detected.
- MutableMenuX, an extension of MutableMenu from https://www.b4x.com/android/forum/threads/class-mutablemenu-alter-menu-at-runtime.30325/
- wmPreferences, which works for both B4A and B4J (I started to create it before Erel published B4Xpreference).
If the user presses the Puck’s button ‘x’ times within the configured time interval, the Puck will start broadcasting a 'panic' message and all of its LEDs will start flashing, telling the user that now a panic message is being broadcast, and the app will pick this message up and then send an SMS to the configured phone number; the default text (which can be changed in the preferences) is "I have pressed the PANIC button, please call me and if I don't pick up, please call emergency services". Once the user presses the button an additional time, the panic message is no longer broadcast; instead, a battery level message is sent out.
Caveats:
- For some reason - I don’t know why and it might be a mistake of mine, but this does the trick for me and I don’t intend to publish the app on Google Play so it’s irrelevant to me - in the Manifest, leave targetSDKversion to 14; with 26, the BLE stuff doesn't work.
- When 'scanning' is enabled, the app will consume more battery power as it will then use a partial lock to ensure the CPU stays alive even when the device is on lock screen (there’s no point in having a panic button that doesn’t do that).
- The Puck’s JavaScript code in the example is set to only count 500ms presses to avoid false positives (you may want to read - a lot - on the Espruino site to see what I mean). In other words, the user must press the Puck's button for half a second, 'x' times, within the configured interval.
Quick start guide:
- Install the JavaScript code on the Puck; modify it so that the 'puckname' variable has a value you will recognise. Modify other configurable values too, if desired.
- Install the app on the phone.
- Set the preferences in the app (see menu).
- In the 'Scan' menu, enable 'Show all'.
- Check out the BLE broadcasting devices that are shown in the CustomListview now, and tap your Puck, so that it will be saved as 'the relevant one'.
- Start scanning and hope the app will never send you an SMS.
Enjoy!
