Hi all,
I have a project in mind, but I don't know if it is possible with Arduino, and I don't know what components I need.
What I would like to make/program is the following.
An analogue clock (with one pointer, only showing the hour) that is working, giving the current time when my phone is connected with it (via bluetooth). As soon as my phone is no longer connected, the clock should stop running. But when my phone reconnects (because I am in the vicinity), the clock should switch to the correct time and keep on running. It does not matter if the pointer turns, or the plate with the hour.
Probably I need a stepper motor to rotate the pointer ... but what do I need to get the bluetooth connection and how should I program that if the phone makes connection, the clock starts working, and if it loses connection that it stops working.
I have basic programming knowledge, so if I get a start, I will probably figure out the rest myself.
The idea is indeed about a parking disc. But a parking disc that keeps on running and changing the hour continously is forbidden.
So I thought something else. If the disc is behind the window, it connects with the phone while the driver is in the car. While connected with the phone, the disc is rotating. As soon as the driver parks the car and gets out, the connection with the phone is lost and the disc/clock stops rotating, but the disc is automatically at the correct starting time. When the driver returns, the disc has to forward the time so the clock is adjusted, and then keeps.on running again.
I don't know all of the specifics, but what I can tell you is that this will require both an Arduino to control the clock, and a custom app on your phone that can connect to the Bluetooth connection and can also communicate the current time.
The clock should be the easy part. Use a stepper motor or a servo, and connect it to a set of gears so that the motor moves 1 minute per minute. Connect a Bluetooth board to the Arduino that can send and receive data (such as an HM-10). Then, in your Arduino code, create a serial connection to the BT board. In the main loop, keep testing to see if the BT connection is valid and, if it is, read the current time from the phone and send the data over to the Arduino, move the servo at a high speed to catch up to the proper time (you may need an encoder on the clock here so that the Arduino can figure out what time the clock currently reads), then go back to standard speed and let the clock run while constantly testing that the BT connection is still there.
As far as the app on your phone, you need to add a section of code that allows you to see nearby BT devices and connect to one of them. You may need nearby devices permission granted by the user of the phone. Then you need some code to either get the time from your phone, or from a website. Then you need some code detect when a BT connection is made and send the time out over the BT connection. Tie it all together with some nice colors and labeled buttons, and sideload it on your phone. It may be possible to use something like the MIT App Inventor (free on the web) to design a simple app like this. I have made a working BT connection with the MIT App Inventor before and it works good enough.