The execution time of your loop() will be slightly longer when the CPU
runs at 8 MHz v.s. 16 MHz, but I don't expect the difference
to be significant. CPU-bound functions, such as digitalWrite(), will
run at half the speed. These functions, however, are quite fast. In
contrast, analogRead() is slow, as it takes roughly 110 µs to
execute, so ...
I would like to know if they can be connected and, if so, how.
but can we place the shield on the breadboard
No, the pins are misaligned and won't plug in.
and use jumper wire to connect the necessary pins so the Mini can use the WiFi
Yes - connect the jumper wires directly to the WiFi shield pins.
If so, how would we know which pins are ...
This is the standard FTDI Basic connections. CTS is an input to the module and is typically just connected to Gnd as seen on the right side here from the Arduino Promini schematic (so the FT232 is always Clear(ed) To Send, i.e. no flow control is used).
DTR may be broken out on one of the side holes. RTS may work for you in place of DTR to create the reset ...
On the datasheet for the Atmega328P, in the Analog-to-Digital Converter section, is the sentence:
The voltage reference may be externally decoupled at the AREF pin by a capacitor for better noise performance.
The internal voltage reference may thus be decoupled by an external capacitor at the AREF pin to improve noise immunity.
Thus the ...
can I feed NRF24 directly from Vcc pin?
NO: the pro mini is either 5V or not strong enough to power the RF24.
EDIT: the 3V3 pro mini "could" power the RF24 via VCC, if you use the cap and if it's not the PA&LNA model (or in full power mode). Best practise is to use an external regulator.
if I fed NRF24 directly from battery and reduce 3.7V to 3.3V ...
The CNY70 is just an IR LED and IR Phototransistor. You can treat the IR LED (emitter) portion of it just like any LED and size the resistor appropriately.
The receiver is just a phototransistor which can operate at anything from about 1V up to 32V with no need to adjust anything. The resistor used there is merely a pullup resistor. You can think of the ...
I finally made it work, thx @domen.
I looked at the other part of the schematic and found I was using the wrong pin - I have two LDO and the one I was using was deactivated for sensor.
Thanks all for your help.
This may be a little left field, but I use the ADC6 and ADC7 inputs to detect switches. I just don't use the digitalRead() function, but instead use analogRead() function. Using a resistor network and switches and some decoder software code in our sketch, we can use a single input pin to interface with many more switches. The switches can only be on one ...
You can't, or at least you can't do it the way you want to. Each pin can give you a maximum of 40mA. You may try using more than one pin but that possibly wont work for you. I suggest you supply additional power from a separate source and control On/Off from Arduino. It would be like a relay. Or simply buy a relay to do this.