I'm using a Nano 33 BLE 'simple' (no Sense, no IoT). The Bluetooth connection with my Android device (a Samsung tablet or a very recent smartphone) is very unstable. To test the connection, I use the application LightBlue. Sometimes the Nano local name appears, sometimes it doesn't. When it appears, sometimes the data are available, sometimes they aren't. I deleted all Delay() instructions.
At the moment, I can't make the connection anymore. I pressed the reset button, I disconnected then connected the usb cable. Again and again. Without success.
The Nano board is connected to a Uno board by wire, with a master (Nano) / slave (Uno) connection. Is it possible that the problem is due to the Nano power made only by the usb port?
Can I make power with the Vin input Nano port and the 5.5V output Uno port (the Uno is powered by a 12V charger) ?
Even with the example LED (it creates a BLE peripheral with service that contains a
characteristic to control an LED), the issue is exactly the same. In the past, I used it with a Uno Wifi Rev2 board and that was working normally. So, problem with power? With the board?
A lot depends on the ambient electrical noise and the distance from receiver to the transmitter. They can give you fits if they are to close together, that will overload the front end of the receive causing noise type of problems due mainly to clipping. Try separating them more and or reducing the transmitter power.
The unstable Bluetooth connection could be due to the Nano BLE drawing power only from the USB port. Using the Vin input on the Nano and the 5.5V output on the Uno might provide more stable power if the power supply can deliver enough current. Interference with other wireless signals could also be a possible issue.
There is about 1 to 2 meters between both devices. And nothing has changed since my previous tests (LED and a direct usb connection without any other connections) with this Nano BLE and the Uno Wifi Rev2.
I'm like a beginner in Arduino but I have to say that I'm a bit disappointed with Arduino. The Uno Wifi Rev2 didn't work anymore (not recognized by Windows), a simple Uno has been broken (I don't know exactly why, maybe due to the Vin jumper of the motor shield not fully cut but the board is striped at that place after cutting and cutting) and now this Nano BLE doesn't work anymore. This system seems not reliable. That's too bad.
A voltage higher then the part rating can destroy and or damage it in a few nanoseconds. The ratings, limits, etc are on the data sheet. It also tells you exceeding them will destroy the part. Not completely cutting that jumper could do the damage in nanoseconds, that is not the fault of the product but it is a user application fault.
That may a user fault but that is also a manufacturer fault, considering the design. The motor shield is intended to be often used with an external power. Other manufacturers include a switch jumper, so that the board is not modified and the user can always choose the configuration. It's a nonsense, in 2023, to force the user to modify a new board for a common use.
My motor shield has a strip between the pads after cutting and cutting. If I continue to use a cutter between the pads, I'll get a hole in the motor shield. There is no apparent link between the pads. But the multimeter finds a continuity... How to explain that?
How to explain that the Nano BLE loses its connection frequently? I'm not the only people who gets this problem.
About the jumper, I don't use anymore the external power, only a 12V from the Uno. And I get an output voltage. Does that mean that the jumper is not fully cut?
I have definitively cut the jumper. There is no continuity anymore after many efforts. But the Uno board is a bit hot under the power port (12V). Is it normal?
I powered the Nano BLE with 5.5V by means of the Uno but the BLE connection is still unstable. It's impossible to really use this configuration in practice.
Please note that the Uno is a bit hot only when I connect it to the Nano by means of the 5.5V (to the Vin Nano pin) and GND (to the GND Nano pin) pins. Is it possible to explain that?
And now, with the LED example, the led is always off when I change the written value even if the connection is right. The serial monitor writes 'led on' but the led is still off.
At this point I think a schematic of how you have connected the devices would be a big help. Be sure all the connections are identified. Also post links to the technical information on the hardware devices.
1 wire between the Uno 5.5V pin and the Nano Vin pin
1 wire between a Uno GND pin and a Nano GND pin.
So, my last test to do, before asking a return or preferably a refund, is a power supply with a 9V battery. Maybe the BLE connection will be stable. Otherwise, that means that there is no reliablity for the current products, maybe due to the previous (and current?) problems in electronic components manufacturing in the world.
The Vin Pin needs about 7 volts to operate properly. 5V on Vin is not enough for proper operation. Hint: A Power Supply the Arduino is NOT! The 9V smoke alarm batteries are not powerful enough to keep the Arduino running. Connecting to the USB should make it work.
Do you mean that I have to use a 7V or 9V charger to power the Nano? But the 9V battery I'm using is a 'big' battery (6LR61).
As I explained in my 1st message, the Uno and the Nano are connected with I2C. The Nano BLE receives data from a tablet with BLE, and the Nano sends them to the Uno with I2C. Without a computer USB/COM connection.
Anyway, I make some progress to know why the BLE connection is unstable. With the LED example, there is in fact no problem (if the serial is open, I forgot sometimes to open it), only a problem with the led which is broken.
It seems that the I2C wire connection is the cause of the unstability of the BLE connection. At the moment, the Nano BLE cannot manage properly both connections in the loop of the sketch.