http://forums.leaflabs.com/topic.php?id=74227 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:04:43 +0000 http://bbpress.org/?v=1.0.2 q http://forums.leaflabs.com/search.php http://forums.leaflabs.com/topic.php?id=74227#post-105470 Fri, 18 Jul 2014 22:05:23 +0000 gbulmer 105470@http://forums.leaflabs.com/ <p>Thank you Okie, that's very kind of you to say.</p> <p>Lots of people put time and effort into helping it along, so it was a lovely experience for me.</p> <p>Fairly clearly, it's aims and constraints are different from the original mini. It was driven to be 'DIYable' using SMD technology used by 13yo at British schools.</p> <p>I like the design because it's a 2-sided PCB, with 8mil track/space rules, and drills 0.5mm or bigger (except one, which can be fudged), so it should be practical to get it made locally in many parts of the world. Further, all the parts are 'big', and so should be feasible for many people to assemble by hand. </p> http://forums.leaflabs.com/topic.php?id=74227#post-105468 Fri, 18 Jul 2014 18:03:05 +0000 okie 105468@http://forums.leaflabs.com/ <p>That looks great! </p> http://forums.leaflabs.com/topic.php?id=74227#post-105211 Sat, 08 Feb 2014 08:08:25 +0000 crenn 105211@http://forums.leaflabs.com/ <p>When I get some more PCBs made, I'll have to check out the new revision. Thanks for the updates gbulmer! Sorry I haven't posted in a while, life is a little busy again. </p> http://forums.leaflabs.com/topic.php?id=74227#post-105197 Thu, 23 Jan 2014 12:34:56 +0000 Adam 105197@http://forums.leaflabs.com/ <p>This is really cool! I look forward to building one!</p> <p>Here's the link to the source code including the Eagle files on gbulmer's github account:</p> <p><a href="https://github.com/gbulmer/openstm32hw/tree/master/Orone-mini-v0/Orone-mini-S8K-v0r001" rel="nofollow">https://github.com/gbulmer/openstm32hw/tree/master/Orone-mini-v0/Orone-mini-S8K-v0r001</a></p> <p>Here's an image of the board layout:</p> <p><a href="https://github.com/gbulmer/openstm32hw/blob/master/Orone-mini-v0/Orone-mini-S8K-v0r001/Orone-mini-S8K-v0r001.brd.png" rel="nofollow">https://github.com/gbulmer/openstm32hw/blob/master/Orone-mini-v0/Orone-mini-S8K-v0r001/Orone-mini-S8K-v0r001.brd.png</a> </p> http://forums.leaflabs.com/topic.php?id=74227#post-105196 Thu, 23 Jan 2014 10:26:23 +0000 gbulmer 105196@http://forums.leaflabs.com/ <p><a href="https://github.com/gbulmer/openstm32hw/tree/master/Orone-mini-v0/Orone-mini-S8K-v0r001">Orone-mini-S8K</a> ECAD is published. </p> <p>This is a further improvement on the Orone-mini-S8J. One of my rules is to create a new part number whenever the external pin-out changes. Another rule is to create a new part number when functionality changes. S8K has both types of change.</p> <p>S8K is a significant rework of Maple-mini.<br /> It implements many improvements to become more robust, easier to use, more flexible, and is designed to be as DIY-friendly as practical, while still being usable on breadboard. </p> <p>Further details are explained in the github repo, but an example of flexibility is support for STM32F303 (thanks to ventosus), a Cortex-M4 MCU with significantly enhanced peripherals and memory.</p> <p>S8K adds a 'pukka' circuit connecting the USB shield (and USB cable sheath) to USB ground. Maple-mini and Maple don't connect them. Recommendations are remarkably inconsistent across industry experts on this connection, so I will try to write a blog on the options. I believe the effect of this new addition should be reduced electromagnetic interference (EMI), better electrostatic discharge (ESD) protection, and a better ground connection.</p> <p>S8K needed a new thru-hole mini-USB footprint to enable USB ground and USB shield to be connected. That needs testing by making a PCB.</p> <p>The parts are all DIY-friendly. As I've mentioned before, some local schools teach 13yo's to make surface mount with 1206 parts.<br /> The PCB uses modest 8mil track/8 mil space design rules, so it should be manufacturable by your favourite PCB house. All drills are 0.5mm or bigger except one 0.4mm. Please feedback if that causes any problems (it may be fixable for you in the DRC values).</p> <p><strong>WARNING</strong>: I haven't updated the BoM yet. This is missing some part numbers, and others are wrong.</p> <p>Summary of changes (including S8J):<br /> - Larger, easier to assemble USB circuit, without sacrificing any ESD protection<br /> - av+ from analogue power supply (aim is less electrical noise, and better ADC performance)<br /> - reworked ground plane and crystal oscillator for better ground and lower noise<br /> - circuit connecting USB shield and USB ground to improve EMI, ESD and ground</p> <p>It feels like S8K answers all outstanding requirements I know of, and is pretty close to "as good as I can do with what I know today", so I'd like to say ...</p> <p>Thanks to everyone for help, sharing, advice and encouragement.<br /> Thanks to to the LeafLabs folks for Maple &amp; family and continuing to support this forum. Thanks to Siy for blazing a trail, inspiring, and sharing designs and thoughts; to ventosus, for building the first S8x variants, feedback, ADC testing and the STM32F303 libmaple port; to crenn, Adam, and soycamo for builds, feedback and ideas; to feurig for kicking off the thread, and sharing practical experience; to ala42 for sharing expertise and software; to Laen of OSHPark.com for PCB &amp; CAM debugging and help; to the Maple community for discussions and ideas; to Tekwizz members for focusing on 'DIY-able'.</p> <p>Thanks to Mark Rafter, Jeff Smith, Dr Tony Wilcox and Chris Evans for long-term help, advice, facilities, discussions and support. Thanks to Pete Harrison for generously giving many, many hours of reviews, help, ideas, and most recently for asking "why isn't the USB shield connected?"<br /> If I've forgotten anyone, I apologise now, and ask you to please let me know so I can correct my mistakes.</p> <p>(It's Eagle 5.x because I know someone with a paid-for license who helps me :-)</p> <p>(Full disclosure: I am not a member of LeafLabs staff.) </p> http://forums.leaflabs.com/topic.php?id=74227#post-105128 Sat, 04 Jan 2014 23:13:43 +0000 gbulmer 105128@http://forums.leaflabs.com/ <p>Folks, I've released a new design, <a href="https://github.com/gbulmer/openstm32hw/tree/master/Orone-mini-v0/Orone-mini-S8J-v0r001">Orone-mini-S8J</a> at github.</p> <p>It is significantly improved over the earlier Orone-mini-S8H.</p> <p>Several people who built the earlier Orone-mini designs fed back on their experiences. All identified the difficulty of assembling the board using the small NUF2042XV6 USB EMI/ESD. So I have adopted the much larger STF202-22. It is the same part as used on Siy's designs. However, that circuit leaves the USB +5 power line (Vusb) unprotected. So Orone-mini-S8J has a separate discrete Transient Voltage Suppression (TVS) diode protecting the Vusb connection.</p> <p>Ventosus ran some <a href="http://forums.leaflabs.com/topic.php?id=10410&amp;page=7#post-25373">tests to measure the ADC noise performance</a> of Orone-mini vs Maple. The test results indicated Orone-mini was worse than Maple analogue-power, but better than Maple digital power. As that generation of Orone-mini only connected the digital power supply to av+, and is only a two layer PCB, it was very encouraging.</p> <p>I've changed the design, so that Orone-mini-S8J now provides av+ from its analogue-power supply. </p> <p><em>Note: the analogue supply is only useful to provide external power from av+ when Orone-mini is connected to, about, 9V or less. Several Maple-mini's had suffered voltage regulator failure, which was the reason the earlier Orone-mini's had av+ connected to Orone-mini's higher capacity digital power supply. Just like Maple mini, the small analogue-PSU voltage regulator used for the analogue power supply is limited by its power dissipation. This should not effect Orone-mini when it's run from 5V, by powering it over USB</em></p> <p>The board has been extensively reworked to improve the integrity of the ground plane and power distribution (i.e. fewer big holes :-). </p> <p><em>Note:</em>These changes necessitated changes to the pin-out of the extra signals and voltages that Orone-mini provides, but which are not available on Maple-mini. Hence Orone-mini-S8J is not pin identical to Orone-mini-S8H. However Orone-mini-S8J is pin identical to Maple-mini.</p> <p>The silk screen has been slightly updated to highlight the Serial Wire Debug (SWD) pins, making it easier to use with a JTAG-SWD debugger, for example an ST-Link/V2 or the even lower cost ST-Link/V2 on STM32FxDiscovery boards (under $10). These debuggers support hardware break-points, data watch points, single-stepping, etc. using gdb.</p> <p>Orone-mini is fully pin-compatible, and software compatible with Maple-mini if you assemble it with an STM32F103CB.</p> <p>Orone-mini can also be assembled using an STM32F303CC, doubling its Flash, and more than doubling SRAM, It could be used with Ventosus' initiated libmaple port for STM32F303. This would have similar performance to an Arduino Due for a similar cost to an eBay clone of an Arduino UNO.</p> <p>An STM32F303Cx has more, and better peripherals than an STM32F103CB.<br /> For example:<br /> - 4 ADCs vs 2 ADCs, and ADC's are 5msps vs 1Msps (potentially 20Msps vs 2Msps)<br /> - Dual DAC vs none<br /> - 3 SPI vs 2<br /> - 2 advanced timers vs 1 (useful for e.g. brushless motor control)<br /> - 2 I2S vs none<br /> - 17 channel capacitive touch sensing vs none<br /> - 7 analogue comparators vs none<br /> - 4 programmable gain op amps vs none<br /> etc.</p> <p>AFAIK, an STM32F303 has some much better peripherals than an Arduino Due's SAM3X8E, for example better ADC and analogue signal processing. Further, STM2F303 has 5V tolerant pins, though Due's SAM3X8E has more I/O.</p> <p>Orone-mini-S8J retains Orone-mini's benefits, described at github.</p> <p>Summary of changes:<br /> - Larger, easier to assemble USB circuit, without sacrificing any ESD protection<br /> - av+ from analogue power supply (aim is less electrical noise, and better ADC)<br /> - reworked ground plane and crystal oscillator for better ground and lower noise</p> <p>This is an initial release; I have not yet updated the Bill of Materials. Please feedback any comments on this thread.</p> <p>Please do not use the design yet. It is not adequately quality assured.</p> <p>(Full disclosure: I am not a member of LeafLabs staff.) </p>