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A Multimeter is the sure fire way of telling if metal thingie one is connected to metal thingie two.
A Multimeter is the sure fire way of telling if metal thingie one is connected to metal thingie two.
A Magnifying glass also helps if you are trying to see quite where the tiny bit of solder has bridged between two tracks on a piece of stripboard.
A Magnifying glass also helps if you are trying to see quite where the tiny bit of solder has bridged between two tracks on a piece of stripboard.
+
+===A Multimeter ?===
+Yes, the essential first purchase after the soldering iron.
+At minimum it will measure three things
+====Voltage====
+The potential difference in Volts between two points.
+Selected with a V Dc or Dc Volts setting on the control knob.
+A battery is an obvious example. You will see them with voltages from half a volt up to 20 Volts and more. The meter will show you the voltage.
+Reerse the leads notice the display now shows -20Volts. You are measuring the difference between two voltages, even if one of them os at 0V and attached to all the metal around you. Volts are always about differences.
+
+====Current====
+No of electrons flowing per second
+
+It might be tempting to simply put the meter when set to amps across the battery we measured in Volts, but this is not a good idea. A current measurement is measuring how many electrons are flowing. And if we do this with a voltage we have just measured are then we are effectively connecting the two voltages together and as much electricity as can will flow. A SHORT CIRCUIT!
+Since our the electronic we have constructed does not behave like a short circuit (Hopefully!) then there must be something limiting the current. V= IR, Resistance ! The Next measurement .
+So in small electrical circuits we tend not to measure too much current, because it normally involves breaking a wire to perform the measurement. Measuring current consumption of a Pi can be an indicator of problems but ensuring a reliable way of actually making the measurement with a Pi & a Multimeter can get rather involved. Best measured on a Bench Power Supply. The net purchase. . .
+But I digress, The Pi acts as a resistance and using the two equations of electricity
+
+'''V=IR Voltage (Volts) = Current(Amps) * Resistance (Ohms) '''
+
+&
+
+'''W=VI Power (Watts) = Voltage (Volts) * Current (Amps) '''
+
+Looking at the Zynth here I'm dring it from a 12V power supply into a hifiberry Power Amp Card.
+
+My Bench top power supply shows a voltage of 12.27 Volts, 0.460 Amps and 5.656 Watts
+
+The Maths checks out (fairly closely to an engineering accuracy)
+
+12.27 * 0.460 = 5.6442
+
+So it's right to about two decimal places 9 this is a whole area in itself...)
+
+
+So we know the Pi is consuming 5.6 Watts of power.
+
+And here's the clever bit. A Pi runs from 5V so we can calculate the Current flowing into the Pi by playing with the same equation again.
+
+W = IV
+5.64 Watts = Current * 5 Volts
+
+So the current = 5.64/5 = 1.128 Amps
+====Resistance====
==How does the zynthian understand the encoders?==
==How does the zynthian understand the encoders?==