2 Replies Latest reply on Feb 24, 2018 5:44 PM by user_457816629

    PSoC 5LP CY8CKIT-059 wiring board

    user_457816629

      FRC team 5563 has been working with the CY8CKIT-059 as the basis for a custom drive station.  The platform has been simple to use and highly educational, the only complaints are minor - there is no way to mount the board securely and wiring is sometimes tedious.  So to fix this, we created a board.

         

      Attached are the KICAD design files - the schematic, board database and the project files.  The present incarnation, which is provided in the attached files, uses 100% through hole parts for easy hand assembly.  We built a version of the board with surface mount components but we found that it was hard for the team to work on without a real SMT workstation.  Because KICAD uses separate files to contain component footprints which are "joined" to the schematic prior to board layout, we were able to use the same schematic for the surface mount and the through hole board.  So while we have not gotten our hands on the through hole boards, we have tested the design.  KICAD is a FOSS board design package that is a available freely for Linux/MAC/Windows. 

         

      The attached files can be used by anyone as a starting place for customization or just to send for fabrication as-is.  If you only one or two boards, our team will be running a small fundraiser immediately after kickoff should someone want to purchase a few.

        • 1. Re: PSoC 5LP CY8CKIT-059 wiring board
          pkx
                  This is great. I hope other teams can use it.   
          • 2. Re: PSoC 5LP CY8CKIT-059 wiring board
            user_457816629

            Assembly Instructions

             

            Team 5563 will be giving away raw boards to other teams they meet at competitions.  To facilitate this, I had promised to create an assembly document and post it online.  I’m not producing an assembly instruction set - really, the assembly is obvious to anyone who has ever soldered electronics, and as trying to use a soldering iron on your own with no instruction is a formula for at least a wicked burn, I’m not supplying instructions.  If you don’t know what to do with the board seek out a knowledgeable mentor on your team (or another team) please.

             

            The one thing that is not easily determined, is the bill of materials for the PCB we created.  Attached to this post is a LibreOffice spreadsheet providing part numbers and the approved vendor list for the board. I have the following to say about the BOM.

             

            Wire terminals:

            The board was designed with 3.5mm pitch spring clamp wire terminals in mind.  These are very similar to the terminals that FIRST loves for the main fuse panel.  There are a number of manufacturers that make these connectors but they are not 100% compatible with each other.  As a result, I created a composite part decal (part footprint / mounting pattern / there are lots of names) that will accommodate many different manufacturer’s parts.  HOWEVER – there is always a however – the board probably will have physical interference problems if you try to mix connector vendors; if you use the same vendor for all these connectors you will be OK.  I can recommend the following vendors:

             

            • Molex 39700-0704, 39700-0705, 39700-0706 www.molex.com

            Molex donated connectors when we were making the prototype.  I had put in a sample request using a work email and a few days afterwards I received an email saying that these parts weren’t typically in sample stock for North America and I would probably only get approval for free parts if I could provide a sizable production quantity.  I replied there would never be any further sales, that I was requesting them for my FIRST team and they should cancel the request.  Ever since I got there reply I’ve liked Molex – they told me that parts had been ordered from Europe and would be in my hands in less than a week.

             

            • On-Shore Technology OSTHC040080,  OSTHC050080,  OSTHC060080 www.on-shore.com

            No great story here, I requested samples and in the request stated that I wanted some for my FIRST team.  I got samples shortly afterwards with a note of “good luck” on the packing slip.

             

            • Phoenix Contacts 1985218 (PTSA 1,5/ 4-3,5-Z), 1985221 (PTSA 1,5/ 5-3,5-Z), 1985234 {PTSA 1,5/ 6-3,5-Z) www.phoenixcontact.com

            I bumped into an employee of Phoenix when they were visiting my office, they sent a pile of parts to let me make units for another team.

             

            If you want to support companies that support FIRST, use one of the above.  I have nothing against any other company that makes these connectors, I just had the above experiences to share.

             

            Resistors:

            R1 through R8 are listed as 330 Ohm resistors but in truth this is just a guess.  Depending on the LEDs you wish to power, you probably will need to change this.  The CY8CKIT-059 runs at 5V and you will need to divide that by the expected LED current draw to determine the resistance.  330 will work for most and supply about 15mA but you really need to verify that will work for your LEDs.

             

            4.7K resistors are needed if you will be using switches that are normally open and close to ground.  The default configuration for the software provided by Cypress is for normally open switches that close to 5V – I presume that this would be a lower current design than the 4.7K design.  However, this meant that the FIRST console thought all the buttons were pressed all the time and were unpressed only when someone pushed them.  If you would prefer to write your driver software to operate this way, you don’t need the 4.7K resistors.  If you care to change the PSOC Creator software to use pull ups, you don’t need these resistors.  I prefer external pullups to explain the circuits to the team but you can find multiple ways to skin this cat.

             

            The balance of the connectors are just 100 mill .025 square post headers and sockets.  You will find representative part numbers in the BOM but if you are like me you have plenty of adequate lab stock to draw from.  I have no stories about wonderful samples on these, though I did get samples from Samtec and Molex so they should at least get some credit for helping.

             

            Of course, you will also need the processor from a Cypress CY8CKIT-059, that is why this is posted here.  I solder a header strip to the bottom of this (equivalent to a Samtec TSW-126-05-G-S) and plug it into the sockets on the board.  If you want, you could skip the sockets on the wiring board and just solder the processor board permanently down.

             

            Finally, there is a place marked “USB” on our board that has two holes near it, one on either side.  This is a place to use a wire to secure the USB cable so that it can not easily get removed.  It might have been better to have made a couple of slots there to use a cable tie – something for the next revision perhaps.