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# '''A third hand.'''
# '''A third hand.'''
## 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.
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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.
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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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Remember Electrons can't see they only go where the voltages tell them.
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A Multimeter is the sure fire way of telling if metal thingie one is connected to metal thingie two.
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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.
==Encoders connected using a MCP23017 chip==
==Encoders connected using a MCP23017 chip==