From mike at chipworks.net Fri May 2 12:36:48 2025 From: mike at chipworks.net (Michael Monaghan) Date: Fri, 2 May 2025 13:36:48 -0400 Subject: [TriEmbed] Battery Discharge Testing Message-ID: Hi everyone, I've been looking for a good guide for doing Battery Discharge Testing. The guides I'm finding look like someone copied someone's homework and added a bunch of words to ensure they met the 10k word requirement. Most seem to be missing a good discussion of the math and testing procedures or spend a lot of time discussing related topics and then glossing over the core subject. As I understand it, I need either a known fixed resistance load or constant current sink within the battery's discharge rate. I'm testing lithium-ion battery packs that are 40v and have a discharge rate of C/2. As the packs are 2A, 4A and 6A that means 1A/2A/3A discharge rates. My current process is to use a 100 ohm load and calculate the discharge time from full charge, 41v, to discharge, 25v. Doing it this way, I know the current across my load will reduce as the battery voltage decreases. Initially that's 0.411A based on measured resistance of the entire load. My Questions: 1. Is my method sound? 2. Should I be using a different method like constant current? 3. Is there a way to compensate for the reduction in current in the results other than using a constant current device? 4. Is [starting current] * [run time in hours] = [Amp Hours] or should I be using something like [average current]? 5. Is there a good guide to the math or actual testing procedures? Here's a link to my first test data. Thanks for any insights. -------------- next part -------------- An HTML attachment was scrubbed... URL: From pete at soper.us Mon May 5 09:41:46 2025 From: pete at soper.us (Pete Soper) Date: Mon, 5 May 2025 10:41:46 -0400 (EDT) Subject: [TriEmbed] Design front end for Kicad Message-ID: <3a33f6ee-36e3-499f-9242-c1eddef20f2a@soper.us> https://github.com/Blinkinlabs/circuitpainter -------------- next part -------------- An HTML attachment was scrubbed... URL: From paulmacdnc at att.net Fri May 9 13:21:04 2025 From: paulmacdnc at att.net (The MacDougals) Date: Fri, 9 May 2025 14:21:04 -0400 Subject: [TriEmbed] Monthly meeting 5/12 at 7:00pm at The Forge Initiative References: <024101dbc10f$20f4dcb0$62de9610$.ref@att.net> Message-ID: <024101dbc10f$20f4dcb0$62de9610$@att.net> We will have our normal monthly meeting on Monday 5/12/25 at 7:00 pm Agenda: - Welcome - Announcements - P.O.T.M. - Show and Tell The plan for this month is to meet in person at: The Forge Initiative 630 Davis Drive, Suite 205 Morrisville, NC We do NOT plan to use jitsi for those who cannot make it in person. ---> Paul -------------- next part -------------- An HTML attachment was scrubbed... URL: From pete at soper.us Mon May 12 11:41:24 2025 From: pete at soper.us (Pete Soper) Date: Mon, 12 May 2025 12:41:24 -0400 Subject: [TriEmbed] email for tonight's TriEmbed meeting Message-ID: <2d896199-10fe-49a2-995d-ddbac6d2db9a@soper.us> Neither Nick or I got Paul's meeting reminder sent Friday. There seems to be something going on with email delivery. On the off chance this was more wide spread, and in case it's intermittent or just picking on Paul, here are the reminder details. https://mail.triembed.org/pipermail/triembed_triembed.org/2025-May/005906.html We hope to see you at the Forge tonight! Pete From pete at soper.us Mon May 12 14:07:55 2025 From: pete at soper.us (Pete Soper) Date: Mon, 12 May 2025 15:07:55 -0400 (EDT) Subject: [TriEmbed] Usenix annual conference is no more (editorial from 50000 feet) Message-ID: <8fa6d896-28fb-4c3d-8dc2-b3a9ff1b5c31@soper.us> https://bcantrill.dtrace.org/2025/05/11/rip-usenix-atc/ Pete -------------- next part -------------- An HTML attachment was scrubbed... URL: From scottghall1 at gmail.com Mon May 19 13:01:18 2025 From: scottghall1 at gmail.com (Scott Hall) Date: Mon, 19 May 2025 14:01:18 -0400 Subject: [TriEmbed] Any experience using the Remote Processor Messaging driver in embedded ARM Linux? Message-ID: *{ please forward this question to any club members ... }* I would love to pick your brain about the API for the RPMsg driver as it is implemented in Debian-based embedded Linux systems (such as Yockto). I need to monitor its activity, like if it has established or lost communications with the remote processor. Please contact me if you have any experience or knowledge. My problem is that I need to reset the remote processor if the communications link goes down, and I need a definitive way to determine that communications break other than creating a keepalive on the remote processor and a timeout on the Linux system if it hasn't received a keepalive within a certain period of time. -- Scott G. Hall Raleigh, NC, USA scottghall1 at gmail.com *Although kindness is rarely a job, no matter what you do it's always an option.* -------------- next part -------------- An HTML attachment was scrubbed... URL: From carl.nobile at gmail.com Thu May 22 14:41:15 2025 From: carl.nobile at gmail.com (Carl Nobile) Date: Thu, 22 May 2025 15:41:15 -0400 Subject: [TriEmbed] Just posted the latest video Message-ID: Hi all, I've just posted the latest video, have fun. https://youtu.be/DLiC4q0fxHg -------------------------------------------------------------- Carl J. Nobile (Software Engineer/API Design) carl.nobile at gmail.com -------------------------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: From pete at soper.us Mon May 26 12:27:54 2025 From: pete at soper.us (Pete Soper) Date: Mon, 26 May 2025 13:27:54 -0400 (EDT) Subject: [TriEmbed] Test 123 Message-ID: <6c7d52a0-af79-4ef7-83f4-b6aa363eb4c9@soper.us> Please ignore -------------- next part -------------- An HTML attachment was scrubbed... URL: From pete at soper.us Mon May 26 16:34:43 2025 From: pete at soper.us (Pete Soper) Date: Mon, 26 May 2025 17:34:43 -0400 (EDT) Subject: [TriEmbed] Email list probably fixed fixed Message-ID: <897e46e3-c74b-44dc-941c-09c9da3e0179@soper.us> The TriEmbed list was broken by a GNU Mailman update in mid-April when a rewrite to use Python3 created a configuration issue. Sorry the fix took so long. Pete -------------- next part -------------- An HTML attachment was scrubbed... URL: From scottghall1 at gmail.com Mon May 26 22:34:58 2025 From: scottghall1 at gmail.com (Scott Hall) Date: Mon, 26 May 2025 23:34:58 -0400 Subject: [TriEmbed] Fwd: Any experience using the Remote Processor Messaging driver in embedded ARM Linux? In-Reply-To: References: Message-ID: I would love to pick your brain about the API for the RPMsg driver as it is implemented in Debian-based embedded Linux systems (such as Yockto). I need to monitor its activity, like if it has established or lost communications with the remote processor. Please contact me if you have any experience or knowledge. My problem is that I need to reset the remote processor if the communications link goes down, and I need a definitive way to determine that communications break other than creating a keepalive on the remote processor and a timeout on the Linux system if it hasn't received a keepalive within a certain period of time. -- Scott G. Hall Raleigh, NC, USA scottghall1 at gmail.com *Although kindness is rarely a job, no matter what you do it's always an option.* -------------- next part -------------- An HTML attachment was scrubbed... URL: From scottghall1 at gmail.com Mon May 26 22:36:47 2025 From: scottghall1 at gmail.com (Scott Hall) Date: Mon, 26 May 2025 23:36:47 -0400 Subject: [TriEmbed] [resend] The Weston Standard Cell In-Reply-To: References: Message-ID: https://youtube.com/shorts/2OksDSv2XVs?si=smE5x8fJUzL9oKmY Bonuses: How To Make Transformers Flame Less: https://youtube.com/shorts/D7UPNgP_kL0?si=Nvb-EBvpMPHDDEu5 Thermocouple: https://youtube.com/shorts/MJN6reAA0No?si=JSxOC-sn08eRJ0p4 The Arduino Finger: https://youtube.com/shorts/rdXAbAcTpqE?si=HJ3KrG2cGViurWOJ Switchcraft 2501: https://youtube.com/shorts/k45vjemqkvg?si=dIHqSxi9nTHStjv5 -- Scott G. Hall Raleigh, NC, USA scottghall1 at gmail.com *Although kindness is rarely a job, no matter what you do it's always an option.* -------------- next part -------------- An HTML attachment was scrubbed... URL: From scottghall1 at gmail.com Tue May 27 21:32:04 2025 From: scottghall1 at gmail.com (Scott Hall) Date: Tue, 27 May 2025 22:32:04 -0400 Subject: [TriEmbed] Any experience using the Remote Processor Messaging driver in embedded ARM Linux? In-Reply-To: References: Message-ID: Info on the Remote Processor Messaging driver can be found here: https://docs.kernel.org/staging/rpmsg.html ST ecosystem info can be found here: https://wiki.st.com/stm32mpu/wiki/Linux_RPMsg_framework_overview And the non-linux side in Analog Devices universe can be found here: https://wiki.analog.com/resources/tools-software/linuxdsp/docs/internal-cores-communication/rpmsg-lite But I am dealing with NXP's multicore chips and finding the interface to be very finicky. I did resolve a problem today where the Linux user-space process would core-dump and I could not figure out why - I was using a C-based function that relied on malloc() in a C++ program and crashed as soon as I attempted to access the allocated memory. Turns out that the rpmsg-lite code on the remote core (ie. the non-Linux core) was scribbling on a shared memory area segment intended for the heap of the Linux process rather than within the rpmsg driver on the Linux side. Much more solid now (thank goodness for open-source and being able to fix it), but there is still some instability in non-happypath instances. That is why I asked my original question hoping that somebody else has worked with the RPMsg driver for Linux talking to a non-linux core utilizing the rpmsg-lite API that shares memory space for passing information between the two, and could help me through some hurdles. Background: I’m using a Cortex-M core running FreeRTOS to manage more deterministic operations with GPIO, timers and thus I2C, SPI, PWM, multiplexed I/O, CANbus and a single UART (modbus), while using quad-Cortex-A cores running Linux to handle the decision logic, networking, video, USB, multi-UART, user interface, and other typical Linux functions. Confusing the issue is my non-expertese regarding the multitude of linker memory segment assignments to code and data segments in an ARM cross-compiler throughout my code (fast-code, slow-code, flash memory, static memory, readonly, permutable, and so on) for the bare-bones (well, FreeRTOS) m-core code. -- Scott G. Hall Raleigh, NC, USA scottghall1 at gmail.com *Although kindness is rarely a job, no matter what you do it's always an option.* On Tue, May 27, 2025, 11:01 AM Nick Edgington wrote: > Not understanding your system clearly. I was a senior Linux cluster > architect at IBM. I work on the installation of cold clusters. I would be > willing to take a look at the problem. > > > > > Nick > > On Mon, May 26, 2025 at 11:35 PM Scott Hall via TriEmbed < > triembed at triembed.org> wrote: > >> >> I would love to pick your brain about the API for the RPMsg driver as it >> is implemented in Debian-based embedded Linux systems (such as Yockto). >> I need to monitor its activity, like if it has established or lost >> communications with the remote processor. >> >> Please contact me if you have any experience or knowledge. My problem is >> that I need to reset the remote processor if the communications link goes >> down, and I need a definitive way to determine that communications break >> other than creating a keepalive on the remote processor and a timeout on >> the Linux system if it hasn't received a keepalive within a certain period >> of time. >> >> >> -- >> Scott G. Hall >> Raleigh, NC, USA >> scottghall1 at gmail.com >> *Although kindness is rarely a job, no matter what you do it's always an >> option.* >> _______________________________________________ >> Triangle, NC Embedded Interest Group mailing list >> >> To post message: TriEmbed at triembed.org >> List info: >> http://mail.triembed.org/mailman/listinfo/triembed_triembed.org >> TriEmbed web site: https://TriEmbed.org >> To unsubscribe, click link and send a blank message: mailto: >> unsubscribe-TriEmbed at bitser.net?subject=unsubscribe >> Searchable email archive available at >> https://www.mail-archive.com/triembed at triembed.org/ >> >> -------------- next part -------------- An HTML attachment was scrubbed... URL: