fix types & other small issues

[offspring]

This is a fix for mixing bool with int example

int writeValue()
{
}

bool subscribe () 
{
   return writeValue();
}

[CLAassistant]

All committers have signed the CLA.

[github-actions]

Memory usage change @ f22ad2e

Board	flash	%	RAM for global variables	%
arduino:mbed_nano:nano33ble	💚 -128 - -64	-0.01 - -0.01	0 - 0	0.0 - 0.0
arduino:mbed_nano:nanorp2040connect	💚 -96 - -88	-0.0 - -0.0	0 - 0	0.0 - 0.0
arduino:megaavr:uno2018:mode=on	💚 -178 - -162	-0.37 - -0.33	0 - 0	0.0 - 0.0
arduino:renesas_uno:unor4wifi	💚 -96 - -80	-0.04 - -0.03	0 - 0	0.0 - 0.0
arduino:samd:mkrwifi1010	💚 -96 - -88	-0.04 - -0.03	0 - 0	0.0 - 0.0
arduino:samd:nano_33_iot	💚 -96 - -88	-0.04 - -0.03	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/Central/LedControl flash	%	examples/Central/LedControl RAM for global variables	%	examples/Central/PeripheralExplorer flash	%	examples/Central/PeripheralExplorer RAM for global variables	%	examples/Central/Scan flash	%	examples/Central/Scan RAM for global variables	%	examples/Central/ScanCallback flash	%	examples/Central/ScanCallback RAM for global variables	%	examples/Central/SensorTagButton flash	%	examples/Central/SensorTagButton RAM for global variables	%	examples/Peripheral/Advertising/EnhancedAdvertising flash	%	examples/Peripheral/Advertising/EnhancedAdvertising RAM for global variables	%	examples/Peripheral/Advertising/RawDataAdvertising flash	%	examples/Peripheral/Advertising/RawDataAdvertising RAM for global variables	%	examples/Peripheral/BatteryMonitor flash	%	examples/Peripheral/BatteryMonitor RAM for global variables	%	examples/Peripheral/ButtonLED flash	%	examples/Peripheral/ButtonLED RAM for global variables	%	examples/Peripheral/CallbackLED flash	%	examples/Peripheral/CallbackLED RAM for global variables	%	examples/Peripheral/EncryptedBatteryMonitor flash	%	examples/Peripheral/EncryptedBatteryMonitor RAM for global variables	%	examples/Peripheral/LED flash	%	examples/Peripheral/LED RAM for global variables	%
arduino:mbed_nano:nano33ble	-64	-0.01	0	0.0	-64	-0.01	0	0.0	-64	-0.01	0	0.0	-64	-0.01	0	0.0	-64	-0.01	0	0.0	-64	-0.01	0	0.0	-128	-0.01	0	0.0	-64	-0.01	0	0.0	-64	-0.01	0	0.0	-64	-0.01	0	0.0	-128	-0.01	0	0.0	-64	-0.01	0	0.0
arduino:mbed_nano:nanorp2040connect	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-96	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0	-88	-0.0	0	0.0
arduino:megaavr:uno2018:mode=on	-166	-0.34	0	0.0	-166	-0.34	0	0.0	-166	-0.34	0	0.0	-166	-0.34	0	0.0	-162	-0.33	0	0.0	-178	-0.37	0	0.0	-178	-0.37	0	0.0	-166	-0.34	0	0.0	-166	-0.34	0	0.0	-166	-0.34	0	0.0	-166	-0.34	0	0.0	-166	-0.34	0	0.0
arduino:renesas_uno:unor4wifi	-96	-0.04	0	0.0	-96	-0.04	0	0.0	-80	-0.03	0	0.0	-96	-0.04	0	0.0	-96	-0.04	0	0.0	-96	-0.04	0	0.0	-96	-0.04	0	0.0	-96	-0.04	0	0.0	-80	-0.03	0	0.0	-96	-0.04	0	0.0	-96	-0.04	0	0.0	-96	-0.04	0	0.0
arduino:samd:mkrwifi1010	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-96	-0.04	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0
arduino:samd:nano_33_iot	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-96	-0.04	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0	-88	-0.03	0	0.0

Click for full report CSV

Board,examples/Central/LedControl<br>flash,%,examples/Central/LedControl<br>RAM for global variables,%,examples/Central/PeripheralExplorer<br>flash,%,examples/Central/PeripheralExplorer<br>RAM for global variables,%,examples/Central/Scan<br>flash,%,examples/Central/Scan<br>RAM for global variables,%,examples/Central/ScanCallback<br>flash,%,examples/Central/ScanCallback<br>RAM for global variables,%,examples/Central/SensorTagButton<br>flash,%,examples/Central/SensorTagButton<br>RAM for global variables,%,examples/Peripheral/Advertising/EnhancedAdvertising<br>flash,%,examples/Peripheral/Advertising/EnhancedAdvertising<br>RAM for global variables,%,examples/Peripheral/Advertising/RawDataAdvertising<br>flash,%,examples/Peripheral/Advertising/RawDataAdvertising<br>RAM for global variables,%,examples/Peripheral/BatteryMonitor<br>flash,%,examples/Peripheral/BatteryMonitor<br>RAM for global variables,%,examples/Peripheral/ButtonLED<br>flash,%,examples/Peripheral/ButtonLED<br>RAM for global variables,%,examples/Peripheral/CallbackLED<br>flash,%,examples/Peripheral/CallbackLED<br>RAM for global variables,%,examples/Peripheral/EncryptedBatteryMonitor<br>flash,%,examples/Peripheral/EncryptedBatteryMonitor<br>RAM for global variables,%,examples/Peripheral/LED<br>flash,%,examples/Peripheral/LED<br>RAM for global variables,%
arduino:mbed_nano:nano33ble,-64,-0.01,0,0.0,-64,-0.01,0,0.0,-64,-0.01,0,0.0,-64,-0.01,0,0.0,-64,-0.01,0,0.0,-64,-0.01,0,0.0,-128,-0.01,0,0.0,-64,-0.01,0,0.0,-64,-0.01,0,0.0,-64,-0.01,0,0.0,-128,-0.01,0,0.0,-64,-0.01,0,0.0
arduino:mbed_nano:nanorp2040connect,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-96,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0,-88,-0.0,0,0.0
arduino:megaavr:uno2018:mode=on,-166,-0.34,0,0.0,-166,-0.34,0,0.0,-166,-0.34,0,0.0,-166,-0.34,0,0.0,-162,-0.33,0,0.0,-178,-0.37,0,0.0,-178,-0.37,0,0.0,-166,-0.34,0,0.0,-166,-0.34,0,0.0,-166,-0.34,0,0.0,-166,-0.34,0,0.0,-166,-0.34,0,0.0
arduino:renesas_uno:unor4wifi,-96,-0.04,0,0.0,-96,-0.04,0,0.0,-80,-0.03,0,0.0,-96,-0.04,0,0.0,-96,-0.04,0,0.0,-96,-0.04,0,0.0,-96,-0.04,0,0.0,-96,-0.04,0,0.0,-80,-0.03,0,0.0,-96,-0.04,0,0.0,-96,-0.04,0,0.0,-96,-0.04,0,0.0
arduino:samd:mkrwifi1010,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-96,-0.04,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0
arduino:samd:nano_33_iot,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-96,-0.04,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0,-88,-0.03,0,0.0