how to calculate current from square pulses

[milner]

my device giving output as square pulses.but would like to control current from the range 50uA to 500uA of square pulses.how to calculate it. can someone help me

[MartinBL]

Can you describe your use case in more detail? What have you connected to the output that is supposed to draw 50 to 500uA?

[milner]

I need to connect my nrf51822 to an electrode. and an electrode is connecting to rat brain.but the square pulses should be controlled. a current of the square pulses should be in the range of 50uA to 500uA. how to calculate the current and voltage from the square pulses

[MartinBL]

• The output voltage on the GPIOs will always be the same as your supply voltage (Vdd).

• The GPIOs on the nRF51 can be configured to supply up to 0.5mA in standard drive and 5mA in high drive.

• You can use timers and GPIOs to make a square wave with various frequencies and duty cycles.

• If you need to control the current sent into the electrodes you will need additional circuitry.

• Since the output voltage is constant you will need to know the load resistance to calculate the current (ohm's law).

• I suppose you can measure the current, but then you will need additional circuitry again.