The use case
General function: This device is for a box where the vehicle glass is lacquered and the car's switch is inserted into it. The user will not need to carry the switch, and when he approaches the car, Bluetooth will unlock with the APP to the steering wheel and remove the car switch and take the key box into the car.
we will need to integrate a way that the original user will have permanent access to the Bluetooth lockbox; in other words, they will be able to always open the lockbox but will also be able to send out a code or access via the app that will allow the secondary user to access it.
A: The device must be at a minimum battery consumption.
To meet this goal, we propose this;
1. Microcontroller and Bluetooth are in sleep mode in normal mode.
2. For example each 10 seconds microcontroller wakes up and wakes Bluetooth up, it will remain on for a 2 second, when it needs to receive a pairing request. And if they did not receive and request, they would go to sleep for the next 10 seconds.
3. If the pairing is requested, the pairing operation is carried out with a pin code and the microcontroller waits to finish the process. If there is no opening command or buzz, it will sleep for about 10 minutes.
B: How to operate the circuit after the pair?
1- The mobile APP sends a character string of 8 bytes as a user password to Bluetooth. If these 8 bytes are correct, the APP screen will be changed and the button for opening will be displayed to identify the location of the vehicle. If the user does not recognize the car accurately, he will hit the beep tab on the app to hear it, and if the open button on the APP is pressed, it will be given a solenoid command for the XMS to open.
2- A micro switch notifies the microcontroller, unlocking the door. If the opening signal from the micro switch was not received by the microcontroller, it will command the solenoid several times with a delay until the door opens.
3- If the password is incorrect, an error message is sent to the APP via Bluetooth. If the error is repeated 5 times, the APP will be notified do not have a reaction even with the correct password for 20 minutes.
4- If item 3 is repeated again, the name of the Bluetooth application will be blocked.
C: Device settings and security. (The following items are for authentication, noun and passwords changes, and a suggestion is that a strong normal process is acceptable in any case. If you have another algorithm, I’m open)
I. the goal is writing simple firmware and app to test the circuit.
II. The above requirements are our suggestions but it is up to you the designing the algorithm of the firmware and the app.
III. Please assume that after this stage we will make the prototype and send you to test and debugging in separate contract.