Hello, I had to put the charging project on hold but will pick it up again soon. I probably blocked excessively on finding an acceptable 10K NTC thermistor with the right B= value.
On Tue, Nov 20, 2018 at 9:25 AM Jason Kridner <[email protected]> wrote: > On Thursday, September 6, 2018 at 10:22:38 AM UTC-4, Fred Kerr wrote: >> >> I am concerned about the battery temperature for safety in my office, >> house, and around my 4-year-old son. :) And I'm curious about logging stuff >> infinitum. >> >> I have it working with a fixed resistor (without attempting charging yet). >> > > Did you ever get your thermistor working and enable charging? > > >> >> On Thu, Sep 6, 2018 at 7:18 AM Graham Haddock wrote: >> >>> Fred: >>> The temperature coefficient is only important if you are going to use >>> them as temperature monitors, and you are going to thermally/mechanically >>> attach them to the battery. >>> >>> If you are just trying to get the battery power supply to run, and are >>> not concerned about battery temperatures, a fixed resistor will work fine. >>> >>> --- Graham >>> >>> == >>> >>> On Thu, Sep 6, 2018 at 3:34 AM Fred Kerr wrote: >>> >>>> I am looking for 10K NTC Thermistors with B=3480. How critical is the B >>>> value, or what range can I accept? Currently I am looking on Mouser. >>>> >>>> Is there a specific or recommended battery pack? I'm just using an >>>> 18650 from a local surplus store. >>>> >>>> Regarding the log file, I still need to do this: >>>> >>>> sudo /opt/scripts/tools/developers/update_bootloader.sh >>>> >>>> I'll also look for 100K thermistor with B=3960 >>>> >>>> On Thursday, August 30, 2018 at 5:35:43 PM UTC-7, Fred Kerr wrote: >>>>> >>>>> It runs well with the soldered implementation. My breadboards are a >>>>> little cheap. >>>>> >>>>> The attached minicom_20180830b.cap shows a boot with microUSB power >>>>> from a wall wart (from my rpi3), then a boot with the battery circuit. I >>>>> left both RX and TX attached; I'll play with disconnecting them another >>>>> time. >>>>> >>>>> I'll look into getting some "telemetry" info from the pocket beagle. >>>>> I'm open to suggestions about things to add/log, etc. Also, I think this >>>>> pocket beagle doesn't have a fix that I got before - after the shutdown, >>>>> things panic. >>>>> >>>>> If anything else jumps out from the log file, please let me know! >>>>> >>>>> On Wednesday, August 29, 2018 at 10:59:03 AM UTC-7, Fred Kerr wrote: >>>>>> >>>>>> I'll try again soon with my more stable circuit (*soldered), also >>>>>> with RX disconnected so I just get output from the Pocket Beagle and the >>>>>> only power input is from the battery circuit. >>>>>> >>>>>> (*Soldered, so no loose breadboard connections, better current >>>>>> carrying capacity, etc.) >>>>>> >>>>>> What is a good way to share log files? Mine can get verbose! I could >>>>>> store it somewhere and post a link - suggestions welcomed! I have a lot >>>>>> of >>>>>> possibilities, but just let me know what works best for you. >>>>>> >>>>>> On Tuesday, August 28, 2018 at 12:51:23 PM UTC-7, Fred Kerr wrote: >>>>>>> >>>>>>> Yes, it ran quite a lot longer on the 1F, but still hung. >>>>>>> >>>>>>> I wired this up (see pic) to be more stable than the breadboard mess >>>>>>> I had. The led on 1.8k resistor is gonna run a lot longer than I'll >>>>>>> take at >>>>>>> lunch!!! >>>>>>> >>>>>>> Can I isolate RX and TX or...oh I just need TX from the beagle for >>>>>>> visibility! >>>>>>> >>>>>>> 1F 5.5v supercap (that battery was discharged to 3.96v). This one >>>>>>> has more charge. Also put a 1000uf electrolytic on the soldered version, >>>>>>> "because". >>>>>>> >>>>>>> Fred Kerr (mobile) >>>>>>> >>>>>>> On Tue, Aug 28, 2018, 12:13 PM Jason Kridner wrote: >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Monday, August 27, 2018 at 11:15:36 PM UTC-4, Fred Kerr wrote: >>>>>>>>> >>>>>>>>> Hello all, >>>>>>>>> >>>>>>>>> I'm being just a little bit careful here: >>>>>>>>> >>>>>>>>> I'm about to try this, but I will connect up the serial terminal >>>>>>>>> first, so I can see output and interact with the board. (Graceful >>>>>>>>> shutdown!) >>>>>>>>> >>>>>>>> >>>>>>>> Don't connect the power or RX (ie., serial cable to PocketBeagle) >>>>>>>> signals to avoid them interfering. Great thing to monitor. >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> I will test the serial connection first with just a micro USB >>>>>>>>> charging cable rather than USB to a computer. (Simplify!) >>>>>>>>> >>>>>>>> >>>>>>>> Not sure what you are testing here. Are you just saying you'll >>>>>>>> power via the microUSB connection and not connect to a computer, just >>>>>>>> to >>>>>>>> see the behavior? You are monitoring with a serial connection? >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> It's my understanding that LiPo charging is disabled or not >>>>>>>>> present in the firmware. (I'll give you the "uname -a" and other info >>>>>>>>> the >>>>>>>>> next time I fire it up. Just let me know what and how to check.) >>>>>>>>> >>>>>>>> >>>>>>>> It is not enabled by default. There is a flag in the PMIC that >>>>>>>> needs to be enabled. We've been playing with a driver to set the flag, >>>>>>>> but >>>>>>>> there are other bugs in that driver not related to actually charging. >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> Also, it's not clear (without reading the data sheet :) ) about >>>>>>>>> the resistor values for the thermistor and the parallel (linearizing?) >>>>>>>>> resistor. >>>>>>>>> >>>>>>>>> If you have a 10K thermistor, do you put it in parallel with a 10K >>>>>>>>> resistor, or likewise 100K thermistor in parallel with a 100K >>>>>>>>> resistor? Do >>>>>>>>> you put the thermistor anywhere in contact with the (e.g., 18650) >>>>>>>>> LiPo? >>>>>>>>> >>>>>>>> >>>>>>>> Looking at the TPS65217 datasheet says to put a 75kohm resistor in >>>>>>>> parallel. >>>>>>>> >>>>>>>> I'm not sure, but I believe the actual thermal resistor should be >>>>>>>> something like >>>>>>>> https://www.ametherm.com/blog/thermistors/thermistors-ntc-thermistor-temperature-sensors-provide-li-ion-battery-safety/ >>>>>>>> . >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> From the prior thread, it seems to be sufficient (if even >>>>>>>>> necessary) just to connect a 10K resistor from TS (P2-16) to ground >>>>>>>>> (P2-15). >>>>>>>>> >>>>>>>> >>>>>>>> Yes, that is supposed to work, ignoring the battery temperature. >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> 10uF cap from battery (P2-14) to ground (P2-15). >>>>>>>>> >>>>>>>>> (Tangent/future: What about larger cap, perhaps using a 5.5V >>>>>>>>> supercap, detect supercap discharging (lipo voltage to ~min input >>>>>>>>> voltage >>>>>>>>> on vbat) and give an interrupt to shut the board down?) >>>>>>>>> >>>>>>>>> >>>>>>>>> Thanks in advance for your help, and to the original thread >>>>>>>>> authors! >>>>>>>>> >>>>>>>>> >>>>>>>>> Other posts that I found: >>>>>>>>> >>>>>>>>> Safely power down the PocketBeagle supplied by a battery (no >>>>>>>>> replies?): >>>>>>>>> >>>>>>>>> https://groups.google.com/d/msg/beagleboard/dDSD89DGzpU/j2WzZyA2CgAJ >>>>>>>>> >>>>>>>> >>>>>>>> I threw in a reply. >>>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Supplying two ICs from the PocketBeagle powered by a Lipo battery >>>>>>>>> >>>>>>>>> https://groups.google.com/d/msg/beagleboard/B7Zyf97hvzY/z8cOt0MHBwAJ >>>>>>>>> >>>>>>>>> I want to do some excessive self-telemetry, both internal and >>>>>>>>> external. I plan to scale the raw battery voltage by 1/11 with an op >>>>>>>>> amp >>>>>>>>> before feeding to one of the 1.8V ADC inputs. I'll defer to >>>>>>>>> suggestions >>>>>>>>> about measuring current. >>>>>>>>> >>>>>>>>> (This is a tangent: I also plan to be paranoid if I connect to a >>>>>>>>> car and want to monitor the car's "12V" with something like a VCO on >>>>>>>>> the >>>>>>>>> car side pulsing to an optoisolator, but I'm sure there are better >>>>>>>>> ideas >>>>>>>>> out there! :) (I could use several PIC -> nrf24l01 for some "really >>>>>>>>> good" >>>>>>>>> isolation!) >>>>>>>>> >>>>>>>>> Thanks, >>>>>>>>> Fred Kerr >>>>>>>>> >>>>>>>>> On Friday, November 10, 2017 at 10:32:46 AM UTC-8, Adam Saenz >>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> Keep in mind that the 7V is Absolute Max voltage so you should >>>>>>>>>> operate below this level or risk damaging the chip. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Thursday, November 9, 2017 at 10:15:05 PM UTC-8, Shannon >>>>>>>>>> Mackey wrote: >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> I expect I'm overlooking something, But it isn't obvious to me >>>>>>>>>>> how to power the PocketBeagle with batteries. It doesn't have a >>>>>>>>>>> similar >>>>>>>>>>> arrangement to BBB. Can someone point me in the right direction, >>>>>>>>>>> please? >>>>>>>>>>> Thanks! >>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>> For more options, visit http://beagleboard.org/discuss >>>>>>>> --- >>>>>>>> You received this message because you are subscribed to a topic in >>>>>>>> the Google Groups "BeagleBoard" group. >>>>>>>> To unsubscribe from this topic, visit >>>>>>>> https://groups.google.com/d/topic/beagleboard/PQCNhmeBK3M/unsubscribe >>>>>>>> . >>>>>>>> To unsubscribe from this group and all its topics, send an email to >>>>>>>> [email protected]. >>>>>>>> To view this discussion on the web visit >>>>>>>> https://groups.google.com/d/msgid/beagleboard/846799d8-d0bf-481a-9599-cd3b97c1b065%40googlegroups.com >>>>>>>> <https://groups.google.com/d/msgid/beagleboard/846799d8-d0bf-481a-9599-cd3b97c1b065%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>>> . >>>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>>> >>>>>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/beagleboard/84b1f839-cfe2-4dff-b9b3-ecffdc9f2527%40googlegroups.com >>>> <https://groups.google.com/d/msgid/beagleboard/84b1f839-cfe2-4dff-b9b3-ecffdc9f2527%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to a topic in the >>> Google Groups "BeagleBoard" group. >>> To unsubscribe from this topic, visit >>> https://groups.google.com/d/topic/beagleboard/PQCNhmeBK3M/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/beagleboard/CANN_KV4icQ5MbPyST%2BSYo_0X9n7_UxudMyCtagT7Oo73qizQ2Q%40mail.gmail.com >>> <https://groups.google.com/d/msgid/beagleboard/CANN_KV4icQ5MbPyST%2BSYo_0X9n7_UxudMyCtagT7Oo73qizQ2Q%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/PQCNhmeBK3M/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/4a0f639c-ea05-4b5e-92e5-f07fadf535e4%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/4a0f639c-ea05-4b5e-92e5-f07fadf535e4%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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