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+==Encoders directly connected to GPIO Pins==
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+Please see the 23017 approach described below.+[[File:Zynthian-amp3-open.jpg|300px|frame|center|Zynthian-amp3-open]]+<br clear=all>+
[[File:Zynsampler-envelope1.png|frame|center|A zynthian parameter page]]
[[File:Zynsampler-envelope1.png|frame|center|A zynthian parameter page]]
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+[[File:Frontal shop product-768x514.jpg|frame|center|Zynthian v5]]
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## A stand that can grab the device as you solder it. IF you intend going near a solderable Pi connector with a soldering iron these are very useful to have.
## A stand that can grab the device as you solder it. IF you intend going near a solderable Pi connector with a soldering iron these are very useful to have.
−You are joining two clean metal surfaces with a metal that melts at a considerably lower temperature. The molten metal makes an excellent electrical bond with the surface of the wire or copper trace on a PCB. However the emphasis is very much on the word clean. Hence the flux. So you apply the flux to all metal parts that are involved in the process. It will heat up as soon as the iron is near and boil off anything on the metal surface that could hinder the joint. It also ensures the solder, when molten, doesn't adhere to the rubbish that the boiling flux removes. All essential when making a reliable, sustainable electrical connection.
+You are joining two clean metal surfaces with a metal that melts at a considerably lower temperature. It is a purely surface effect for the wires being joined. They do not melt, only the solder does. The molten metal makes an excellent electrical bond with the surface of the wire or copper trace on a PCB when in solidifies, and if done properly protects the join from the air, preventing galvanic issues . However the emphasis is very much on the word clean. Hence the flux. So you apply the flux to all metal parts that are involved in the process. It will heat up as soon as the iron is near and boil off anything on the metal surface that could hinder the joint. It also ensures the solder, when molten, doesn't adhere to the rubbish that the boiling flux removes. All essential when making a reliable, sustainable electrical connection.
Soldering has stood the test of time. You can make some fairly ropey connections, but they are surprisingly resilient. Flexible wires will often fail before the solder joint.
Soldering has stood the test of time. You can make some fairly ropey connections, but they are surprisingly resilient. Flexible wires will often fail before the solder joint.
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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====
+
+Resistance is an electrical concept that simply relates current and voltage. It can have very low values 0,.001 ohms(Ω) is the resistance involved in semiconductors and we can also deal with Megaohms, the resistors used in Power Distibution. This is a incredible range of values, but for most electronic use the values are from a few Ω to 10 or so Megaohms, since these are the values resistors can be bought in.
+
+Your meter will measure a resistor in a similar fashion to how you use a multimeter to Voltage. You set the meter to Ohms(Ω) and place the two wires on the ends of the resistor. and the meter display will show the resistance. But there is something subtly different here. To perform this measurement there must be a voltage across the multimeter wires and the meter is actually measuring the current flowing and calculating the resistance to display.
+So there is actually a voltage across the multimeter when set to Ω. Indeed I use it to test LED's a working as it's only 1 or 2 volts. But it isn't a proper power supply. If you measure a Pi this way you may get a reading, but don't expect that to tell you how much current the Pi will use. There are semiconductors(lots of them) in the Pi and these do not present accurate resistance readings in such cases . .
+
+And then we come to
+====Continuity====
+Resistance's rougher cousin.
+
+Frequently, for instance when soldering, you aren't worried as to what the resistance is you simply want to know that electricity has gone where you hoped it would go. And you don't want to be distracted by having to look at the meter screen, you want a noise that indicates when the two leads are directly shorted to each other.
+
+Continuity.
+
+It beeps when the leads are shorted. The meter displays something but I don't think anybody ever reads it.
+This is the mode to use to check soldering.
+
+It checks that things that should be connected are.
+It checks that things that shouldn't be connected aren't.
+
+====Other things the Meter will measure====
+
+Some amazing facilities nowadays.
+Capacitance, Transistor Performance, Temperature
+
+Very useful devices.
==How does the zynthian understand the encoders?==
==How does the zynthian understand the encoders?==
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<br>
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−This is the original approach used from the start the Encoder were connected directly to GPIO pins on the Raspberry Pi. It is not considered as the recommended approach.
+==Which setting do I choose?==
+Start with custom.
+And do not expect to just get it right first time. We frequently see people in pursuit of the official settings, expecting them to match and it all just works. However with the combination of hardware, often being attempted for the first time and the flexible configuration options the odds of you hitting it randomly are pretty small.
+A methodical approach is what you should adopt.
+First use the Select Encoder push switch. This is the most frequently used switch and attempt to just get it working. You can enter -1 ( 0 is actually a used value) into the webconf screen to get zynthian to ignore other pins. And purely concentrate on that one pin and switch.
+If using a MCP23017 be sure you have a recognised response from 12cdetect -y 1 whilst GPIO you will have to check rigourously. But don't attempt anything else, tempting as it might be to get anything else working.
+Next add the Encoder pins for the SELECT encoder.
+After this you will have one encoder working and it will confirm if you have de-bounce issues or that it is going the correct way.
+Then proceed to the other Encoders.
+BACK is probably the next one to do Switch first encoder pins second.
−If whilst doing GPIO connections you find a pin that obstinately refused to work then try a different pin. Raspberry Pi does occasional magic in this area and I've had pins that have worked perfectly in the past just stop working along with the attached encoder.
−Remember
+ Make Notes!!
−You will probably be revisiting all this for some reason, normally expansion, at some later date and it is frustrating to have to work it all out again from scratch.
==Encoders connected using a MCP23017 chip==
==Encoders connected using a MCP23017 chip==
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Make Notes!!
Make Notes!!
+
+==Encoders directly connected to GPIO Pins==
+
+This is the original approach used from the start the Encoder were connected directly to GPIO pins on the Raspberry Pi. It is not considered as the recommended approach.
+
+Please see the 23017 approach described above.
+
+[[File:Zynthian-amp3-open.jpg|300px|frame|center|Zynthian-amp3-open]]
+
+<br clear=all>
+
=== Connecting via the GPIO Pins. ===
=== Connecting via the GPIO Pins. ===