Hi i just want to check if there's codes to display the voltage and current of FTDI cable VCC pin. Image of the board i am using is attached below.
Image of the board i am using is attached below
Oh no it's not.
If the Pro Mini is powered by the VCC pin and you want to read its own VCC, that is possible. Google for secret voltmeter, or readvcc or getvcc.
This is one of them : https://code.google.com/p/tinkerit/wiki/SecretVoltmeter
Alright thanks Peter i will check it out. do you have any idea for current as well?
The ACS712 is a sensor for (large) current. For small currents you could use a shunt resistor and a OpAmp. Is it that important ?
To read a voltage, often a voltage divider is used with two resistors. That secret voltmeter is the ATmega328P chip (the microcontroller on the Arduino board) reading its own voltage. I'm not sure if that is what you want.
yes it's important for me to find the current as i want to determine the total power consume by the arduino board itself. I'm working on a solar panel project thus i want to determine the power efficiency of this whole project.
I think you should measure the current with a multimeter and do some tests and estimage the average current. An accurate current measurement for 1 to 100mA requires a shunt resistor and a OpAmp, and that extra circuit requires current by itself. When the Arduino is busy reading its own current, that also requires extra current, because it could be sleeping instead.
Most Arduino boards use a ATmega328P microcontroller. A standalone ATmega328P can run years on three AA batteries. It is the Arduino board around it, that also uses current. This is about power usage : http://www.gammon.com.au/power
Don’t laugh at me but I thought for years that RX and TX were low when they are not active. They are not, they are high when not active… Okay, go ahead, laugh yourself silly.
Yes, but in the olden days of RS232 a logic “one” was -12V, so therefore when inactive, the line was lower than when active (+12V).