<p>I have a WiFi module that only needs two wires connection to work. These are RX and TX pins connected to Arduino or the CR-10S printer board but I don't know if there is any physical or software UARTs TX and RX pins. My goal is to add a Wifi support to the CR-10S printer. Since this is not Arduino and the pins are not labeled, it's hard to tell which TX and RX pins are not being used.</p>

<p>In the image of my motherboard below, any port or pin with line pointing to is considered as being used by the printing software so I can't used them.</p>

<p><a href="https://i.stack.imgur.com/gGGeo.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gGGeo.jpg" alt="CR-10S printer control board"></a></p>

<p>There are still ports or pins that are not used. Can any one tell if there is a  TX and RX pin that is not being used from the image above? I need them to communicate with the printer wirelessly. </p>

[{'answer_id': 7463, 'author': 'theSealion', 'author_id': 13095, 'author_profile': 'https://3dprinting.stackexchange.com/users/13095', 'pm_score': 3, 'selected': True, 'text': '<p>You are looking for a capacitor that must be connected to Pin 4 of the LM2596.</p>\n\n<p>Maybe you could provide a better picture of that area so we could see the different tracks on the board.</p>\n\n<p>The LM2596 is in the center of the right side of the board (it is also labeled  with LM2596D). The pins should be counted from top to bottom (in your picture)</p>\n\n<p>My guess is, the Elko you are looking for is connected to C31, and you must look for the positive pin.</p>\n\n<p><a href="https://i.stack.imgur.com/1h1U6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1h1U6.png" alt="LM2596 Wiring"></a></p>\n\n<p>In this wiring diagram Cout is the capacitor you are looking for. The SMD Parts R1, R2 and CFF should be R31, R32 and C31 in your picture.</p>\n\n<p>With the corresponging measurements I would say you do not need to replace the capacitors. </p>\n\n<p>In comparison to the old board your board already has the "fix" implemented. </p>\n'}, {'answer_id': 7470, 'author': 'Trish', 'author_id': 8884, 'author_profile': 'https://3dprinting.stackexchange.com/users/8884', 'pm_score': 1, 'selected': False, 'text': '<h1>You are looking at the wrong board</h1>\n<p>Your board might on the surface look like a Creality v 2.0 board, and is indeed from the same family of boards. After trying to discern the parts and finally resorting to google image search, I almost had to maniacally laugh:</p>\n<p>The currently latest version is the <a href="https://www.creality3d.shop/products/mainboard-upgraded-replacement-controller-board-latest-v2-1-version-motherboard-for-creality-cr-10s-s4-s5-3d-printer" rel="nofollow noreferrer">Creality 2.1</a>, but your board clearly is a pre 2.0 board, as the 2.0 and 2.1 are quite similar, almost identical in the areas in question. According to the standard nomenclature, a 2.X board should be a full new engineering or vastly re-engineered board. So I looked up a Creality 1.X board - And indeed, it looks somewhat closer to a CR-10 motherboard in the area around the black capacitor, but that is marked 150/151. So it is <a href="https://www.creality3d.shop/collections/accessories/products/creality-cr-10-motherboard" rel="nofollow noreferrer">not a Creality 1.1.2 / 1.1.3</a>, also known as &quot;CR-10&quot; board.</p>\n<p>My best guess (Confirmed by OP and <a href="https://www.th3dstudio.com/knowledge-base/creality-cr-10-and-cr-10s-models-what-printer-do-you-have/" rel="nofollow noreferrer">this</a>) is, that your board is an intermediate step between the Creality 1.1.x Board for the CR-10 and the <em>new</em> CR-10S 2.0/2.1, so by nomenclature a <em>proto-2.0</em>. Among Makers, it is called &quot;original CR-10S&quot; at times. Your numbers should thus be read from this board:</p>\n<p><a href="https://i.stack.imgur.com/Zgh0z.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Zgh0z.jpg" alt="Original CR10S Board" /></a></p>\n<p>There is a 100/35V/UT Capacity in the indicated spot in both the green and black renditions.</p>\n'}, {'answer_id': 7475, 'author': 'Greenonline', 'author_id': 4762, 'author_profile': 'https://3dprinting.stackexchange.com/users/4762', 'pm_score': 2, 'selected': False, 'text': '<h3>An important note on Voltage Rating</h3>\n<p>Just to add to the existing answers.</p>\n<p>If you are planning on upgrading the capacitors to some with larger capacitance, then assuming that they are for the <em>supply regulation/smoothing</em> then upping the capacitance shouldn\'t be (too much of) an issue. If they are used for <em>timing</em>, i.e. in an <em>RC</em> circuit (which seems unlikely in this particular case), then the capacitance should/must be kept the same.</p>\n<p>However, the <strong>main issue</strong> that I see is that the existing capacitors are rating at 35\xa0V, and you are planning on adding lower rating capacitors, i.e. 16\xa0V. This is asking for trouble and at best an early failure, or blown capacitor.</p>\n<p>The voltage rating should be between 1.5-2.0 times the voltage of the circuit, or better still (possible overkill), double the circuit voltage and then use the next voltage rating.</p>\n<p>So, for a 12\xa0V circuit, use a 25\xa0V rated capacitor, or 35\xa0V. The 16\xa0V is a bit of a no-no, and besides you don\'t want to mix voltage ratings for the same circuit, not a good idea, unless you actually want a common point of failure.</p>\n<p>See sources: <a href="https://electronics.stackexchange.com/questions/15700/selecting-voltage-rate-for-capacitors">Selecting voltage rate for capacitors</a> and <a href="https://electronics.stackexchange.com/questions/13091/high-voltage-capacitor-in-a-low-voltage-system">High Voltage Capacitor, in a low voltage system?</a></p>\n'}]
['https://3dprinting.stackexchange.com/questions/7468', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/9090/']