Hardware Design Guidelines: Difference between revisions

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This is the area we, the DIY community, will list some general Hardware Design Guidelines for circuit boards and electronic devices.   
This area will list some general Design Guidelines for PCBs that will be fabricated on a coop basis and hand-assembled in users workshops.  There are also suggestions for selecting components that will be used to populate these boards.


==Benefits of following the guidelines==
==Benefits of following the guidelines==
We have come into some situations where some boards are using a different standard then others, thus causing confusion when populating a board or making some SSR assemblies incompatible with controllers.  Normally this would not be a problem, but we are finding these things out after the fact. It causes a scramble to try and get it all to work properly. <br>
 
<br>
1) Using common component PCB footprints and outlines eases documentation burdens and helps reduce assembly errors.<br>
Another benefit of following these guidelines is it will allow other to acquire the appropriate tools for assembly, if required, and they will be used continually instead of a one-time deal. Also we will be able to stock up on parts should we need to make a repair or have enough on hand to populate another board of some kind. We will also be able to purchase a larger quantity of certain parts to receive price breaks in anticipation of future population. This will save all of us money in the long run.
2) Using the same components on several boards increases the volume of coop components purchases, thereby decreasing costs through better price breaks.<br>
3) Using common components helps prevent unnecessary duplication of tooling (e.g. expensive connector crimping tools).<br>
4) Helps reduce incompatabilities that interfere with boards working together.<br>


==Using these guidelines==
==Using these guidelines==
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==PCB Design==
==PCB Design==
PCBs intended for coop distribution will often be assembled by people without previous electronic assembly experience.  Therefore, it is strongly preferred that they should be designed using only through-hole components.  They should also include a silk-screen for the component side, with reference designators and polarity indicators for all components.  These reference designators should be visible when the components are installed on the board.
The PCBs traces should be no less than .010". The minimum copper-to-copper spacing should be .010".  The minimum via size should be .020".  All component connections to (ground) planes should include thermal reliefs (wagon-wheels) so that the components can be successfully soldered in place.
*'''Leds''' should be placed with a square pad as the cathode.
*'''Leds''' should be placed with a square pad as the cathode.
*'''Diodes''' should be placed with a square pad as the cathode.
*'''Diodes''' should be placed with a square pad as the cathode.
*'''Power Connectors''' should be placed with a square pad as the ground.
*'''Power Connectors''' should be placed with a square pad as the ground.
*'''Capacitors''' should be placed with a square pad as the positive pin.
*'''Polarized Capacitors''' should be placed with a square pad as the positive pin.
*'''Resistor''' lead spacing should be .400" unless required otherwise.
*'''Resistor''' lead spacing should be .400" unless required otherwise.
*'''Pads''' on the PCB should be .056" diameter with .029" hole, unless otherwise required.
*'''Pads''' on the PCB should be .056" diameter with .029" hole, unless otherwise required.
*'''Mounting holes''' should be .300" diameter with .167" hole. There should be a minimum of 3 mounting holes per board. This size hole will fit a 6/32 screw nicely.
*'''Mounting holes''' should be .300" diameter via with .167" hole. There should be a minimum of 3 mounting holes per board. This size hole will fit a 6/32 screw nicely.
<br>
<br>
==Pinouts==
==Pinouts==
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===595 Style Controllers: Inputs===
===595 Style Controllers: Inputs===
'''595/Grinch Controller RJ45 inputs should be pinned as follows:'''<br>  
'''595/Grinch Controller RJ45 inputs (and daisy-chain outputs) should be pinned as follows:'''<br>  
Pin 1 - Power (optional)<br>  
Pin 1 - Power (optional)<br>  
Pin 2 - no connection<br>  
Pin 2 - no connection<br>  
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===Renard Controllers: Inputs===  
===Renard Controllers: Inputs===  
'''Renard Controller RJ45 inputs (all pins should be connected straight through on controllers):'''<br>  
'''Renard Controller RJ45 inputs (and daisy-chain outputs):'''<br>  
Pin 1 - Ground<br>  
Pin 1 - Ground<br>  
Pin 2 - Ground<br>  
Pin 2 - Ground<br>  

Revision as of 17:12, 15 December 2007

This area will list some general Design Guidelines for PCBs that will be fabricated on a coop basis and hand-assembled in users workshops. There are also suggestions for selecting components that will be used to populate these boards.

Benefits of following the guidelines

1) Using common component PCB footprints and outlines eases documentation burdens and helps reduce assembly errors.
2) Using the same components on several boards increases the volume of coop components purchases, thereby decreasing costs through better price breaks.
3) Using common components helps prevent unnecessary duplication of tooling (e.g. expensive connector crimping tools).
4) Helps reduce incompatabilities that interfere with boards working together.

Using these guidelines

These are only guidelines and should not be treated as gospel. We ask you to adhere to these guidelines when designing new PCB's if you can. If you need to deviate from these guidelines we ask that you specify the deviation in your assembly notes and list them when releasing your design. This way, others will know if there are any compatibility issues. If you are populating a circuit board please double check to make sure these guidelines were followed before you start populating your board based on what you read on this page.

PCB Design

PCBs intended for coop distribution will often be assembled by people without previous electronic assembly experience. Therefore, it is strongly preferred that they should be designed using only through-hole components. They should also include a silk-screen for the component side, with reference designators and polarity indicators for all components. These reference designators should be visible when the components are installed on the board.

The PCBs traces should be no less than .010". The minimum copper-to-copper spacing should be .010". The minimum via size should be .020". All component connections to (ground) planes should include thermal reliefs (wagon-wheels) so that the components can be successfully soldered in place.

  • Leds should be placed with a square pad as the cathode.
  • Diodes should be placed with a square pad as the cathode.
  • Power Connectors should be placed with a square pad as the ground.
  • Polarized Capacitors should be placed with a square pad as the positive pin.
  • Resistor lead spacing should be .400" unless required otherwise.
  • Pads on the PCB should be .056" diameter with .029" hole, unless otherwise required.
  • Mounting holes should be .300" diameter via with .167" hole. There should be a minimum of 3 mounting holes per board. This size hole will fit a 6/32 screw nicely.


Pinouts

Controller Output (SSR Input)

RJ45 controller outputs should be pinned out as follows:
Pin 1 - +5v supply
Pin 2 - Channel 1 output
Pin 3 - reserved
Pin 4 - Channel 2 output
Pin 5 - reserved
Pin 6 - Channel 3 output
Pin 7 - Ground
Pin 8 - Channel 4 output

595 Style Controllers: Inputs

595/Grinch Controller RJ45 inputs (and daisy-chain outputs) should be pinned as follows:
Pin 1 - Power (optional)
Pin 2 - no connection
Pin 3 - Ground
Pin 4 - no connection
Pin 5 - Clock
Pin 6 - no connection
Pin 7 - Data Latch
Pin 8 - Serial Data In/Out

Renard Controllers: Inputs

Renard Controller RJ45 inputs (and daisy-chain outputs):
Pin 1 - Ground
Pin 2 - Ground
Pin 3 - alternate zero-cross input
Pin 4 - Data-
Pin 5 - Data+
Pin 6 - no connection
Pin 7 - Power input (preferably pulsing DC to allow use as both power and zero-crossing source)
Pin 8 - Power input (preferably pulsing DC to allow use as both power and zero-crossing source)

DMX Controllers: Inputs

DMX Controller RJ45 Inputs (per ESTA):
Pin 1 - Data1+
Pin 2 - Data1-
Pin 3 - Data2+
Pin 4 - no connection
Pin 5 - no connection
Pin 6 - Data2-
Pin 7 - Link Common for Data1
Pin 8 - Link Common for Data2

Power Input Connectors

Power Connectors
Pin 1 - Ground

Component Selection

Through-hole parts

Through-hole parts are preferred for coop boards, due to the difficulties in handling and soldering surface-mount components.

Power Connectors

Power Connectors
Molex SL Series headers for low voltage/amperage applications. .100 pad spacing. Example Mouser part number : 538-70543-0037
Molex SL Series plugs for low voltage/amperage applications. .100 spacing. Example Mouser part number : 538-50-57-9403
Molex connector terminals for low voltage/amperage applications. Example Mouser part number : 538-16-02-0102

Jumpers/Headers

Headers
Headers for jumpers due to design/configuration options. any .100 pad spacing header so a standard jumper can be utilized.

Integrated Circuits

IC's
Sockets should be utilized on all IC's. This will prevent overheating of the IC's and ease of replacement if required.

Fuses

Fuses
Fuses should be 5x20mm unless otherwise required.

Screw Terminals

Terminals
Screw Terminals should have a 5.08mm lead spacing. Example Mouser part number : 571-2828374

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