Difference between revisions of "Techniques"

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There are a wide variety of techniques used in electronics.
 
There are a wide variety of techniques used in electronics.
  
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== Circuit Design ==
 +
* [[Basic Circuit Building Blocks]]
  
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== Printed circuit board design/fabrication ==
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== Prototyping ==
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=== Overview ===
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Prototyping circuitboards:
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=== Software Design ===
 
−
See [[#Software_design_tools|Software Design Tools]] below.
 
  
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==== Step by Step by using Software Design Tool ====
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* [[Solderless protoboard]]
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*make sure the dimension and shape of PCB
 
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*make sure the size and location of Via for PCB stand
 
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*Make sure each components footprint.
 
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*each components are placed on suitable place by put on a hardcopy of simulation PCB
 
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*All components get enough clearance between them.
 
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*Silkscreen layout is confirmed.
 
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*PCB is drawn.
 
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*silkscreen adding the following:
 
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**version no.
 
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**organization name
 
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**board name
 
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*Netlist is ran and got a no error result.
 
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*DRC is ran and got a no error result.
 
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*Overall is checked.
 
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*generate Gerber and send to [[PCB Manufacturers]].
 
−
 
 
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=== Manual Design ===
 
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Somepeople do this with layout on clear film or by directly drawing on a circuit board, of even by scratching, grinding....  For now let them google this.
 
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=== Homebrew fabrication ===
 
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Before exploring these techniques, you should understand your options with regard to services such as BatchPCB.com, ExpressPCB.com and PCB123.com. Being able to have several boards fabbed in 2 days for $59 (for example) makes it harder to justify the hassle of etching your own boards at home.
 
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* [http://www.electricstuff.co.uk/pcbs.html "How to make really really good homemade PCBs"] by Mike Harrison 2007
 
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* [[Toner Transfer]] -- This method involves laser printing your PCB design onto paper, then transferring toner onto copper-clad board.
 
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* [[Photoetching]] -- Exposure of PCB designs onto photosensitized copper-clad board.
 
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* [[Chemical Etchants]]
 
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* [http://groups.yahoo.com/group/pcb-gcode "Mechanically etching or milling PCBs. No chemicals!"] -- Use your CNC router/mill to make PC boards.
 
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* [http://openfarmtech.org/index.php?title=Routed_Circuit_Board Open Source Ecology wiki: "Routed Circuit Board"]
 
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* [http://tech.groups.yahoo.com/group/Homebrew_PCBs/ Yahoo group: Homebrew_PCBs · Homebrew Printed Circuit Boards]
 
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* [http://reprap.org/wiki/Automated_Circuitry_Making RepRap wiki] has details on how to use open-source RepRap-based desktop routers to cut PCBs out of copper-clad board.
 
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* [http://www.pabr.org/pcbprt/pcbprt.en.html "pcbprt - Experiments in inkjet PCB printing"] by pascal. Some inkjet printers can print directly CD and DVD. Pascal explains step-by-step how to get those printers to print on copper-clad FR4 to make reasonably good etch resist. The main trick seems to be baking the freshly-printed boards to dry out the ink and get the dyes/pigments to stick to the copper -- otherwise the water-based ink immediately washes off as soon as you drop the board in the etch tank.
 
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* A few people have made "DIY Flex Circuits".[http://diydrones.com/profiles/blogs/diy-flex-circuits]
 
−
 
 
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=== Commercial PCB fabrication ===
 
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* [[Submitting PCB's for fabrication]] -- Common processes for submitting PCB's for fabrication.
 
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* [[PCB Manufacturers]]
 
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* [http://diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A30196 "PCB fabbing advice"] by Chris Anderson 2008
 
−
 
 
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==Best Practices for PCB Layout==
 
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===Theory===
 
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*Provide the easiest path (lowest impedance) for current to flow
 
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**Return current tends to flow directly under signal trace (for PCB having ground plane)
 
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**Inductance increases with length of traces
 
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**Inductance increases with the area enclosed by signal trace and ground
 
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*Prevent digital currents from contaminating analog currents
 
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*Decouple high speed components
 
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*Use ground loop avoidance tehniques
 
−
 
 
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===Design===
 
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*Partition PCB into "analog stuff" and "digital stuff".
 
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*No digital signal traces should cross over analog ground, and vice versa
 
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*For components having both analog and digital signals (e.g. ADC), orientate components so that the analog signal traces goes only over the analog ground plane, and digital signal traces goes only over the digital ground plane
 
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*AGND and DGND of ADC must have a small impedance (i.e. separated by short distance)
 
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*Add decoupling capacitors close to Vcc and DGND of ICs
 
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*Add ferrite beads and capacitors (PI-filter) to power rail for low-pass filtering (reduce ripples).
 
−
 
 
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===Routing===
 
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*Place fixed components first (components location that cannot be changed, e.g. connectors, buttons, etc)
 
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* Make installing parts onto the PCB fast:
 
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** Fastest: No through-hole parts. All surface-mount parts on the bottom side.
 
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** Next-fastest: All through-hole parts on the top side. All surface-mount parts on the bottom side.
 
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*Separate components into groups
 
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**Digital signals only
 
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**Analog signals only
 
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**Digital and analog (Mixed) signals
 
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**High current devices (e.g. led backlight for LCD/buzzer)
 
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*Do not partition ground into analog and digital planes.
 
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**Use a single ground plane. See the "[[#References | Grounding References]]" below.
 
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*Orientate components that have mixed signals according to the orientation of the ground planes, and straddle components over DGND and AGND
 
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*Place digital only components over DGND
 
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*Place analog only components over AGND
 
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[[File:Pcb layout.png|thumb|800px|center|Grounding Example for PCB]]
 
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*Decoupling capacitors should be as close to the ICs as possible
 
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              Vcc
 
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                | | | | |
 
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              +-----------+
 
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  -------+-+--|-+---------|-------- Vcc
 
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        |C|  |    IC    |
 
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  -------+-+--|---------+-|-------- GND
 
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              +-----------+
 
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                | | | | |
 
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                        GND
 
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*Lay critical (noise-sensitive) traces first (e.g. crystal, analog signals)
 
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**As short as possible
 
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**Use 45<sup>o</sup> turnings instead of 90<sup>o</sup>
 
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*Paired signal traces (e.g. TX+, TX- in ethernet chips) should run parallel along each other
 
−
    TX+ -----\
 
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    TX- ----\ \
 
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              \ \
 
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              \ \
 
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                \ \
 
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                \ \------------ TX+
 
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                  \------------- TX-
 
−
 
 
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===References===
 
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*Grounding
 
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**[http://www.hottconsultants.com/pdf_files/june2001pcd_mixedsignal.pdf Partitioning and Layout of a Mixed Signal PCB]: The importance of single ground plane and partitioning of analog and digital signal trace
 
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** [http://techref.massmind.org/techref/noises.htm#unsplit_ground Massmind Techref: "Unsplit ground"]
 
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**[http://www.hottconsultants.com/pdf_files/ground.pdf Ground- A Path For Current Flow]: The importance of decoupling capacitors
 
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**[http://www.ece.msstate.edu/courses/ece4512/des1_syllabus/current/PCB_Layout_Tips.ppt PCB Layout Tips]: a power point presentation
 
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**[http://pemclab.cn.nctu.edu.tw/w3news/%E6%8A%80%E8%A1%93%E5%A0%B1%E5%91%8A/TR-040.%E9%9B%BB%E8%B7%AF%E6%9D%BF%E4%BD%88%E5%B1%80%E5%8E%9F%E5%89%87/html/layout.htm PCB Layout Guidelines]: in Traditional Chinese
 
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*Crystals and Oscillators
 
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**[http://www.atmel.com/dyn/resources/prod_documents/doc8128.pdf AVR186]: Best Practices for the PCB layout of Oscillators
 
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*ADC & Analog Filters
 
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**[http://ww1.microchip.com/downloads/en/DeviceDoc/adn007.pdf ADN007]: Techniques that Reduce System Noise in ADC Circuits
 
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**[http://ww1.microchip.com/downloads/en/DeviceDoc/ADN010.pdf ADN010]: Predict the Repeatability of your ADC to the BIT
 
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**[http://ww1.microchip.com/downloads/en/AppNotes/00699b.pdf AD699]: Anti-Aliasing, Analog Filters for Data Acquisition Systems
 
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**[http://ww1.microchip.com/downloads/en/AppNotes/00682c.pdf AN682]: Using Single Supply Operational Amplifiers in Embedded Systems
 
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**[http://ww1.microchip.com/downloads/en/AppNotes/00990a.pdf AN990]: Analog Sensor Conditioning Circuits - An Overview
 
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*EMC
 
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**[http://www.atmel.com/dyn/resources/prod_documents/doc1619.pdf AVR040]: EMC Design Considerations
 
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**[http://www.freescale.com/files/microcontrollers/doc/app_note/AN1705.pdf AN1705]: Noise Reduction Techniques for Microcontroller-Based Systems
 
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** [http://www.st.com/stonline/books/pdf/docs/4988.pdf AN898: EMC general information]
 
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** [http://www.st.com/stonline/books/pdf/docs/4967.pdf AN901: EMC guidelines for microcontroller-based applications]
 
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** [http://www.st.com/stonline/books/pdf/docs/9914.pdf AN1709: EMC design guide for ST microcontrollers]
 
−
 
 
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== Circuit construction (Prototyping - Other than custom PCB) ==
 
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* [[Solderless protoboard]] ([http://en.wikipedia.org/wiki/Breadboard Wikipedia:Breadboard]) ([http://www.best-microcontroller-projects.com/prototyping.html a simple example with a small microcontroller])
 
 
* [[Point-to-point]] ([http://en.wikipedia.org/wiki/Point-to-point_construction Wikipedia:Point-to-point construction])
 
* [[Point-to-point]] ([http://en.wikipedia.org/wiki/Point-to-point_construction Wikipedia:Point-to-point construction])
 
* [[Wirewrap]] ([http://en.wikipedia.org/wiki/Wire_wrap Wikipedia:Wire Wrap])
 
* [[Wirewrap]] ([http://en.wikipedia.org/wiki/Wire_wrap Wikipedia:Wire Wrap])
 
* [[Dead bug style]]
 
* [[Dead bug style]]
−
* [[Manhattan style]] aka [http://ciphersbyritter.com/RADELECT/BREADBD/BREADBD.HTM "A Modern Breadboarding Technology: Insulating Pads Soldered to a Ground Plane"]
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* [[Manhattan style]]
 +
* Board-less construction, not sure there is a name for it, can be very cool see: http://runawaybrainz.blogspot.co.uk/2012/04/audio-crystal-cmoy-freeform-headphone.html this one is potted in clear plastic.
 
* [http://www.qrp.pops.net/ugly.asp "Ugly Construction"] (like deadbug... )
 
* [http://www.qrp.pops.net/ugly.asp "Ugly Construction"] (like deadbug... )
 
[http://www.techlib.com/electronics/construction.html "Construction Ideas"] has nice photographs of the above circuit construction techniques.
 
[http://www.techlib.com/electronics/construction.html "Construction Ideas"] has nice photographs of the above circuit construction techniques.
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* [[Stripboard]] (Veroboard): ([http://en.wikipedia.org/wiki/Stripboard Wikipedia:stripboard].)
 
* [[Stripboard]] (Veroboard): ([http://en.wikipedia.org/wiki/Stripboard Wikipedia:stripboard].)
  
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== Soldering techniques ==
+
Most of these techniques are designed to use through-hole devices with pins on 0.1" centers -- and vice versa: most through-hole devices are designed to fit into stripboard or other prototyping board with holes on 0.1" centers.
 +
 
 +
So how do people prototype something with a surface mount device (SMD)?
 +
* Some people continue to use prototyping boards with 0.1" holes, with a bit of creativity, for some SMT devices ([http://www.flickr.com/photos/nshdot/6034580576/in/photostream/])([http://www.flickr.com/photos/nshdot/6034026371/in/photostream])([http://www.flickr.com/photos/nshdot/6034580678/])([http://www.flickr.com/photos/nshdot/6034045085/in/photostream])
 +
* Some people solder many SMT devices to tiny "generic" "surface-mount prototyping boards", then those tiny boards wired together into a complete system (perhaps also including through-hole parts on a stripboard or solderless breadboard). ([http://www.whitewing.co.uk/protoboard.html "Universal through-hole and SMD prototyping board"]), ([http://www.schmartboard.com/ Schmartboard] [http://tech.groups.yahoo.com/group/schmartboardsv/ Schmartboard forum]), ([http://www.capitaladvanced.com/products.htm "Surfboards"]). Alas, none of these are completely generic for most kinds of SMT parts the way that stripboard is completely generic for almost all kinds of through-hole parts.
 +
* Some people buy a [[demo board]] with the SMT part already soldered to it; then these small boards can be wired into a complete system (perhaps also including through-hole parts on a stripboard or solderless breadboard).
 +
* Sometimes people are forced to build a big custom PCB with precise footprints adapted to that SMD device. (This seems to be what manufacturers that make SMDs expect you to do).
 +
 
 +
== PCB Design/Fabrication ==
 +
[[Printed Circuit Boards]]
  
 +
== Soldering Techniques ==
 
* [[Basic soldering]] -- How to use a soldering iron.
 
* [[Basic soldering]] -- How to use a soldering iron.
 
* Surface Mount
 
* Surface Mount
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''Hackaday has lots of other similar articles: [http://hackaday.com/?s=solder+paste search hackaday for "solder paste"]''
 
''Hackaday has lots of other similar articles: [http://hackaday.com/?s=solder+paste search hackaday for "solder paste"]''
  
−
== [[Hardware tool]]s ==
+
(Optional: ) After all the parts are completely soldered down, some people like to spray the board with some kind of conformal coating, or completely seal in the board with some kind of potting compound.
 +
See [http://electronics.stackexchange.com/questions/5095/whats-the-best-way-to-protect-a-board-from-corrosion-in-a-hot-moist-environment "Electronics and Robotics: What's the best way to protect a board from corrosion in a hot/moist environment?"].
 +
 
 +
== [[Hardware tool | Hardware Tools]] ==
 
A directory of [[hardware tool]]s that you may find useful.
 
A directory of [[hardware tool]]s that you may find useful.
  
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== [[software tool]]s ==
+
== [[Software tool | Software Tools]] ==
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== Software design tools ==
 
−
 
 
 
A directory of [[software tool]]s that you may find useful.
 
A directory of [[software tool]]s that you may find useful.
−
 
  
 
== [[PC-Microcontroller Communications]] ==
 
== [[PC-Microcontroller Communications]] ==
−
 
 
Discussion of the various methods to connect a microcontroller or embedded system to a PC...
 
Discussion of the various methods to connect a microcontroller or embedded system to a PC...
  
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Humans writing a program almost always do it in a language.  Here is a section that discusses some of these languages: [[Programming Languages]]
 
Humans writing a program almost always do it in a language.  Here is a section that discusses some of these languages: [[Programming Languages]]
  
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== driving motors ==
+
== Driving Motors ==
−
 
 
 
See [[Stepper Motor Tester]] and [[motor driver]].
 
See [[Stepper Motor Tester]] and [[motor driver]].
  
 
== Enclosure ==
 
== Enclosure ==
−
 
 
* The Earth Signal should short to whole metal Case
 
* The Earth Signal should short to whole metal Case
 
* Digital/Analog GND should separate to this Earth Signal, and should connect a Y-cap. to filter the noise between them.
 
* Digital/Analog GND should separate to this Earth Signal, and should connect a Y-cap. to filter the noise between them.
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== Misc Tips Tricks ==
 
== Misc Tips Tricks ==
−
 
 
[[Misc Tips Tricks]]
 
[[Misc Tips Tricks]]
−
 
  
 
== Further Reading ==
 
== Further Reading ==
−
 
 
* [http://airborn.com.au/method/ "Electronics Design" from Airborn] gives an overview of the complete process: specification, (schematic) circuit design, layout, prototypes, firmware, pilot run, production.
 
* [http://airborn.com.au/method/ "Electronics Design" from Airborn] gives an overview of the complete process: specification, (schematic) circuit design, layout, prototypes, firmware, pilot run, production.
 
* EDA electronic design automation software is a subset of CAD in general. Is there a wiki that discusses CAD in general? Until I find it, I'm going to post these tools here: "Google SketchUp is a powerful yet easy-to-learn 3D software tool" http://sketchup.google.com/ ; "Inkscape is the best tool for SVG standard vector graphics" http://wiki.inkscape.org/ ; Visual Wiki http://visualwiki.org/
 
* EDA electronic design automation software is a subset of CAD in general. Is there a wiki that discusses CAD in general? Until I find it, I'm going to post these tools here: "Google SketchUp is a powerful yet easy-to-learn 3D software tool" http://sketchup.google.com/ ; "Inkscape is the best tool for SVG standard vector graphics" http://wiki.inkscape.org/ ; Visual Wiki http://visualwiki.org/
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== Environmental Issues ==
 
== Environmental Issues ==
−
 
+
See [[better for the environment]].
−
see [[better for the environment]].
 
−
 
 
  
 
[[Category:Techniques]]
 
[[Category:Techniques]]

Latest revision as of 17:38, 11 November 2014

There are a wide variety of techniques used in electronics.

Circuit Design[edit]

Prototyping[edit]

Prototyping circuitboards:

"Construction Ideas" has nice photographs of the above circuit construction techniques. ["Effects Building Techniques" by R.G. Keen 1999 reviews, compares, and contrasts these techniques for circuit construction -- also a few more.

Most of these techniques are designed to use through-hole devices with pins on 0.1" centers -- and vice versa: most through-hole devices are designed to fit into stripboard or other prototyping board with holes on 0.1" centers.

So how do people prototype something with a surface mount device (SMD)?

  • Some people continue to use prototyping boards with 0.1" holes, with a bit of creativity, for some SMT devices ([1])([2])([3])([4])
  • Some people solder many SMT devices to tiny "generic" "surface-mount prototyping boards", then those tiny boards wired together into a complete system (perhaps also including through-hole parts on a stripboard or solderless breadboard). ("Universal through-hole and SMD prototyping board"), (Schmartboard Schmartboard forum), ("Surfboards"). Alas, none of these are completely generic for most kinds of SMT parts the way that stripboard is completely generic for almost all kinds of through-hole parts.
  • Some people buy a demo board with the SMT part already soldered to it; then these small boards can be wired into a complete system (perhaps also including through-hole parts on a stripboard or solderless breadboard).
  • Sometimes people are forced to build a big custom PCB with precise footprints adapted to that SMD device. (This seems to be what manufacturers that make SMDs expect you to do).

PCB Design/Fabrication[edit]

Printed Circuit Boards

Soldering Techniques[edit]

(Have you seen this CNC solder paste/pick n place ?) Hackaday has lots of other similar articles: search hackaday for "solder paste"

(Optional: ) After all the parts are completely soldered down, some people like to spray the board with some kind of conformal coating, or completely seal in the board with some kind of potting compound. See "Electronics and Robotics: What's the best way to protect a board from corrosion in a hot/moist environment?".

Hardware Tools[edit]

A directory of hardware tools that you may find useful.

Software Tools[edit]

A directory of software tools that you may find useful.

PC-Microcontroller Communications[edit]

Discussion of the various methods to connect a microcontroller or embedded system to a PC...

Embedded System Programming and Testing[edit]

To add to the confusion programming in embedded system can mean a person writing a program or a device called a programmer "burning" a program into a chip. This section is for the "burning" meaning of programming.

  • Many systems use JTAG for programming and testing. (Such as Atmel AVR embedded systems]).
  • Other systems use some other kind of in-circuit programming.
  • Some people use bootloaders to make re-programming a little quicker.

-- not sure that this next one is not misplaced ? -- We're talking about "programming and testing" ? What else do you use to test op-amp circuits?

Humans writing a program almost always do it in a language. Here is a section that discusses some of these languages: Programming Languages

Driving Motors[edit]

See Stepper Motor Tester and motor driver.

Enclosure[edit]

  • The Earth Signal should short to whole metal Case
  • Digital/Analog GND should separate to this Earth Signal, and should connect a Y-cap. to filter the noise between them.
  • Attention: do not place near between Earth Signal and Digital/Analog GND, otherwise some spark come out, and affect your whole system.
  • See enclosures.

Misc Tips Tricks[edit]

Misc Tips Tricks

Further Reading[edit]

Environmental Issues[edit]

See better for the environment.

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