https://wiki.techno-innov.fr/api.php?action=feedcontributions&feedformat=atom&user=CyprienTechno-Innov's Wiki - User contributions [en]2026-05-27T01:00:43ZUser contributionsMediaWiki 1.41.0https://wiki.techno-innov.fr/index.php?title=File:CyprienARPhoto.jpg&diff=35File:CyprienARPhoto.jpg2020-09-04T01:16:52Z<p>Cyprien: </p>
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<div></div>Cyprienhttps://wiki.techno-innov.fr/index.php?title=File:FTDIBasic.jpg&diff=34File:FTDIBasic.jpg2020-09-04T01:16:31Z<p>Cyprien: </p>
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<div></div>Cyprienhttps://wiki.techno-innov.fr/index.php?title=File:CyprienARSchemat.png&diff=33File:CyprienARSchemat.png2020-09-04T01:16:18Z<p>Cyprien: </p>
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<div></div>Cyprienhttps://wiki.techno-innov.fr/index.php?title=User:Cyprien&diff=32User:Cyprien2020-09-04T01:14:52Z<p>Cyprien: Created page with "== FTDI Basic auto-reset for LPC == right LPC micro-controlers can be programmed using the standard serial line using the ISP mode. This requi..."</p>
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<div>== FTDI Basic auto-reset for LPC ==<br />
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[[Image:CyprienARSchemat.png|right]]<br />
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LPC micro-controlers can be programmed using the standard serial line using the ISP mode. This requires to have the <code>ISP</code> pin grounded when the LPC goes out of reset. It's often done using two micro-switches you have to manually press and release in the correct order.<br />
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As I am using the FTDI Basic module from Sparkfun to connect to the serial line, I made this circuit to use the <code>DTR</code> modem signal to easily reset and enter ISP mode.<br />
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[[Image:FTDIBasic.jpg|200x200px|center]]<br />
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How does it work?<br />
* When the <code>DTR</code> signal goes up, the <code>Reset</code> is pulled down, putting the LPC into reset. At this moment C1 starts to discharge through R3, and if <code>DTR</code> is asserted long enough, the <code>ISP</code> pin is put low too.<br />
* When <code>DTR</code> is back to normal, the LPC goes out of <code>Reset</code>, and if C1 is discharged enough enters <code>ISP</code> mode.<br />
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I used 2200 ohm for R3 and 47uF for C1 (which I had close), which gives a RC time of about 100ms. Note that a smaller capacitor can be used, as soon as R3 value is adapted. In my experience a 100ms <code>DTR</code> signal is enough to trigger both Reset and ISP mode, whereas a 10ms signal just triggers Reset. This is perfect!<br />
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Cons: if you want to manually push the reset button, disconnect the ISP pin as it will likely be triggered.<br />
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Here's a picture of the circuit soldered on a Vero Board (compact, some holes hold two pins together) and connected to the [[Products/DTPlug|DTPlug]] :<br />
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[[Image:CyprienARPhoto.jpg|535x400px|center]]<br />
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== Next Hack ==</div>Cyprien