https://pranav083.github.io/categories/open-source/Recent content in Open Source on Pranav KumarHugo -- gohugo.ioenCopyright © 2016–2030, Pranav KumarSun, 20 Dec 2020 00:00:00 +0530https://pranav083.github.io/post/stepper_stspin220/Sun, 20 Dec 2020 00:00:00 +0530https://pranav083.github.io/post/stepper_stspin220/ <p><strong>Open source · C++ / Arduino · <a href="https://github.com/pranav083/Stepper_STSPIN220-library">github.com/pranav083/Stepper_STSPIN220-library</a></strong></p> <p>An Arduino library for STMicroelectronics' <a href="https://www.st.com/resource/en/datasheet/stspin220.pdf">STSPIN220</a> low-power stepper driver. It is my most-used piece of open-source work.</p> <hr> <h2 id="why-it-exists">Why it exists</h2> <p>The STSPIN220 can microstep down to <strong>1/256 of a full step</strong> — fine enough for 3D printers, camera slides, and any application where audible stepping or positional granularity matters.</p> <p>Existing Arduino stepper libraries treated the driver as a step-and-direction black box, leaving the microstepping mode fixed in hardware. That throws away the part of the chip that makes it interesting.</p>https://pranav083.github.io/post/project/gsoc-beaglebone-pru/Tue, 20 Aug 2019 00:00:00 +0530https://pranav083.github.io/post/project/gsoc-beaglebone-pru/ <p><strong>Google Summer of Code 2019 · BeagleBoard.org</strong></p> <p>My first sustained open-source contribution, and the work that pulled me toward low-level systems.</p> <hr> <h2 id="the-problem">The problem</h2> <p>The PocketBeagle is small, capable, and short on GPIO. Many embedded projects need more digital I/O than the header exposes, and the standard answer — shift registers — is well understood in principle but poorly documented in practice for this board, particularly for <em>bidirectional</em> operation.</p> <h2 id="bidirectional-io">Bidirectional I/O</h2> <p>I built and documented a set of interfacing configurations against the BeagleBone and PocketBeagle:</p>