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 <[email protected]> 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/9c1f28a5-b34a-4851-bdae-3b9de793fffc%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
minicom_20180830b.cap
Description: application/cap
