<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/rMoTqSC9wrY" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
In this tutorial you will design and build your own keyboard. You will also learn all the essentials to design and build any electronics. Enjoy!
    </div>
    
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="https://github.com/FEDEVEL/custom-keyboard">Github (HW + 3D + SW)</a></li>
            <li class="links-list-item"><a href="https://fedevel.com/courses">FEDEVEL Online courses</a></li>
        </ul>
    </div>  
</div>

Tutorial - Custom DIY Keyboard Design and Build | Part 2: Keyboard Schematic

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/N4cLFE0FF2U" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
        In this tutorial you will design and build your own keyboard. You will also learn all the essentials to design and build any electronics. Enjoy!
    </div>

    <div class="blog-content-chapters">
        <div>
            Chapters:
        </div>
        <ul class="chapters-list">
            <li class="chapters-list-item"><span class="chapters-time">00:00</span><span class="chapters-text">What is this tutorial about</span></li>
            <li class="chapters-list-item"><span class="chapters-time">03:34</span><span class="chapters-text">Starting a new project</span></li>
            <li class="chapters-list-item"><span class="chapters-time">08:42</span><span class="chapters-text">Adding RP2040</span></li>
            <li class="chapters-list-item"><span class="chapters-time">14:43</span><span class="chapters-text">Adding 100nF</span></li>
            <li class="chapters-list-item"><span class="chapters-time">20:12</span><span class="chapters-text">Adding 2.2uF</span></li>
            <li class="chapters-list-item"><span class="chapters-time">23:14</span><span class="chapters-text">Adding 200R</span></li>
            <li class="chapters-list-item"><span class="chapters-time">25:43</span><span class="chapters-text">Adding 27R</span></li>
            <li class="chapters-list-item"><span class="chapters-time">27:40</span><span class="chapters-text">Adding USB-C connector</span></li>
            <li class="chapters-list-item"><span class="chapters-time">31:25</span><span class="chapters-text">Adding ESD protection</span></li>
            <li class="chapters-list-item"><span class="chapters-time">34:03</span><span class="chapters-text">Adding 1uF</span></li>
            <li class="chapters-list-item"><span class="chapters-time">36:10</span><span class="chapters-text">Connecting USB CC pins</span></li>
            <li class="chapters-list-item"><span class="chapters-time">36:46</span><span class="chapters-text">Adding 5.1k</span></li>
            <li class="chapters-list-item"><span class="chapters-time">38:21</span><span class="chapters-text">Voltage regulator 5V to 3V3</span></li>
            <li class="chapters-list-item"><span class="chapters-time">42:27</span><span class="chapters-text">Adding 47uF</span></li>
            <li class="chapters-list-item"><span class="chapters-time">45:49</span><span class="chapters-text">Crystal ABM8-272-T3</span></li>
            <li class="chapters-list-item"><span class="chapters-time">47:22</span><span class="chapters-text">Adding 1k</span></li>
            <li class="chapters-list-item"><span class="chapters-time">48:32</span><span class="chapters-text">Adding 15pF</span></li>
            <li class="chapters-list-item"><span class="chapters-time">49:48</span><span class="chapters-text">Adding 1M</span></li>
            <li class="chapters-list-item"><span class="chapters-time">52:52</span><span class="chapters-text">Flash W25Q128JVS</span></li>
            <li class="chapters-list-item"><span class="chapters-time">58:20</span><span class="chapters-text">Boot Select Button</span></li>
            <li class="chapters-list-item"><span class="chapters-time">1:01:09</span><span class="chapters-text">Adding 100k</span></li>
            <li class="chapters-list-item"><span class="chapters-time">1:03:10</span><span class="chapters-text">Reset Button</span></li>
            <li class="chapters-list-item"><span class="chapters-time">1:04:28</span><span class="chapters-text">Adding 10k</span></li>
            <li class="chapters-list-item"><span class="chapters-time">1:08:23</span><span class="chapters-text">Adding 1x3 Header</span></li>
            <li class="chapters-list-item"><span class="chapters-time">1:11:50</span><span class="chapters-text">User LED</span></li>
            <li class="chapters-list-item"><span class="chapters-time">1:15:06</span><span class="chapters-text">Power LED</span></li>
            <li class="chapters-list-item"><span class="chapters-time">1:16:38</span><span class="chapters-text">Thank you for watching</span></li>
    </div>
    
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="https://oshwlab.com/robertferanec/custom-keyboard">Finished project (EasyEDA)</a></li>
            <li class="links-list-item"><a href="https://github.com/FEDEVEL/custom-keyboard">Github (HW + 3D + SW)</a></li>
            <li class="links-list-item"><a href="https://www.thingiverse.com/thing:6784228">Thingiverse (3D)</a></li>
            <li class="links-list-item"><a href="https://www.youtube.com/playlist?list=PLXvLToQzgzdftro2qK5In8p6ExsDFdpzw">Link to the complete playlist</a></li>
            <li class="links-list-item"><a href="https://fedevel.com/courses">FEDEVEL Online courses</a></li>
        </ul>
    </div>  
</div>

Tutorial - Custom DIY Keyboard Design and Build: Schematic + PCB + Case | Part 1 - RP2040

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/Lqc1jmbSxnE" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
Why is the thickness of PCB layers important? Explained.
    </div>

    <div class="blog-content-chapters">
        <div>
            Chapters:
        </div>
        <ul class="chapters-list">
            <li class="chapters-list-item"><span class="chapters-time">00:00</span><span class="chapters-text">What is this video about</span></li>
            <li class="chapters-list-item"><span class="chapters-time">00:36</span><span class="chapters-text">What is PCB stackup</span></li>
            <li class="chapters-list-item"><span class="chapters-time">01:08</span><span class="chapters-text">Is stackup important?</span></li>
            <li class="chapters-list-item"><span class="chapters-time">01:37</span><span class="chapters-text">Layer thickness vs. crosstalk</span></li>
            <li class="chapters-list-item"><span class="chapters-time">03:37</span><span class="chapters-text">Layer thickness vs. track width</span></li>
            <li class="chapters-list-item"><span class="chapters-time">05:11</span><span class="chapters-text">Layer count and order</span></li>
            <li class="chapters-list-item"><span class="chapters-time">07:44</span><span class="chapters-text">Conclusion</span></li>
    </div>
    
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="https://fedevel.com/courses">FEDEVEL Online courses</a></li>
        </ul>
    </div>  
</div>

How to choose PCB?

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/y22Ia6gJDr8" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
        I had to remove one chip, so I took a short video about it. You may find it useful. Simple technique to remove a small chip with Exposed pad.
    </div> 
</div>


Easy desoldering of 8-pin DFN with Exposed pad

<div class="entry-content">

    <div class="blog-content-img-wrapper">
        <img src="https://assets.fedevel.com/blog/2019/10/30078-layout-example-e1370523993840.jpg" alt="layout-example" />
    </div>

    <div class="blog-content">
        <h2 class="blog-content-heading">Tip 1: Be aware of software compatibility</h2>
        <ul class="content-list">
            <li class="content-list-item"><span class="content-text"><b>Use the same DDR Memory chips as used on the reference board</b><br>
                Why? Different DDR2 / DDR3 memory chips may require different memory controller settings. If the settings in memory controller registers are not correct, your board may not boot.</span></li>
            <li class="content-list-item"><span class="content-text"><b>Use the same FLASH memory chip as used on the reference board</b><br>
                Why? Different NAND FLASH may not be recognized by bootloader and board may not boot. For prototype, use exactly same chip & same size as used on the reference board.</span></li>
            <li class="content-list-item"><span class="content-text"><b>Use same peripheral chips as used on the reference board</b><br>
                e.g Audio, Ethernet, … Why? If you use same chips as used on the reference board, your peripherals will be already supported by the software delivered with the reference design. Otherwise, it may take a lot of effort to add a working driver.</span></li>
            <li class="content-list-item"><span class="content-text"><b>Map devices to the same address as on the reference board</b><br>
                e.g. use same chipselects, base address, … Why? Peripherals may not be recognized or found by bootloader or OS if mapped to a different place. Software modifications is then required.</span></li>
        </ul>
    </div>

    <div class="blog-content">
        <h2 class="blog-content-heading">Tip 2: Be aware of component availability</h2>
        <ul class="content-list">
            <li class="content-list-item"><span class="content-text"><b>Be sure, you can buy all the components from standard suppliers and in required quantity.</b><br>
                Some reference schematics are build from very hard or impossible to get components. Some component manufacturers ask design companies to use their chips to become more famous, but the manufacturer can be very small, hard to contact or  – too famous (they will ignore you). These may be for example manufacturers of power supply chips, passive components or very specific peripherals. Don’t use them, find a replacement. Two examples – Realtek and Winbond – their components are extremely hard to get.</span></li>
        </ul>
    </div>

    <div class="blog-content">
        <h2 class="blog-content-heading">Tip 3: Choose a right replacement</h2>
        Don’t forget. ARM boards are very software depended. Hardware has to be supported by software – usually by Bootloader and in OS. Otherwise, source code modification is need. This can sometimes be very very difficult, time consuming and even impossible.<br>
        <ul class="content-list">
            <li class="content-list-item"><span class="content-text"><b>What if you have to use a peripheral which is not on the reference board?</b><br>
                First of all, have a look at ALL available reference schematics for your chip. Don’t look only in chip manufacturer schematics, check also some other designs using same chip. If you can not find any reference schematic, look for any board using same CPU and have a look what exact chips they used for your peripheral.<br><br>
                Why? If someone used it, there is a pretty good chance it will work. If you select a chip without checking, it may not work in your design – even if it should. Many chips have bugs / errata and may not behave based on specification (for example, recently I had this problem with TI & AMD processors – one didn’t meet GMII specification, the other one LPC specification – they only worked with particular peripheral chips).</span></li>
        </ul><br>
        Once your prototype is up and running, you can experiment and test bigger memories or different manufacturers.<br><br>

        Let me know if this post was helpful for you! Thank you.
    </div>

</div>

3 Tips for ARM Board Prototype Design

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/8GpsPRjvUXk" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
        This video explains difference in layout between DDR3 (fly-by topology) and DDR2 (T-branch topology). This short video is a part of Advanced PCB Layout Course.
    </div> 
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="http://www.fedevel.com/welldoneblog/2011/02/ddr-ddr2-ddr3-pcb-layout-examples/">Download the layout examples</a></li>
            <li class="links-list-item"><a href="https://fedevel.com/courses/advanced-pcb-layout-course">Advanced PCB Layout Course</a></li>
        </ul>
    </div> 
</div>


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DDR2 & DDR3 layout difference

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Tutorial - Custom DIY Keyboard Design and Build | Part 2: Keyboard Schematic

Tutorial - Custom DIY Keyboard Design and Build: Schematic + PCB + Case | Part 1 - RP2040

How to choose PCB?

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