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by ag123
Tue Oct 20, 2020 2:54 am
Forum: Off topic
Topic: charging lipo batteries
Replies: 12
Views: 1007

Re: charging lipo batteries

thanks all, i did a little google (re)search on the topic and stumbled into many articles apparently the most common charging strategies for lithium ion batteries is constant current below 4.2v and constant voltage 4.2v at the end. there are quite many articles around the internet https://en.wikiped...
by ag123
Sun Oct 18, 2020 12:53 pm
Forum: Off topic
Topic: charging lipo batteries
Replies: 12
Views: 1007

Re: charging lipo batteries

i see, in that case my guess is that it may be possible with a parallel capacitor that would smooth out the voltage transitions with pwm so that an average voltage of 4.2v is maintained. the pwm duty cycle can probably be reduced as the variation about 4.2v approaches zero
by ag123
Sun Oct 18, 2020 7:44 am
Forum: Off topic
Topic: charging lipo batteries
Replies: 12
Views: 1007

Re: charging lipo batteries

Yup, thanks Ray, saw a graph like such ;) I'm thinking in terms of pulsing a P channel mosfet and charging the li-ion battery. STM32's adc can monitor voltages at the terminals. When the mosfet is off the input would be the open circuit voltage of the solar cells and the other end the residual volta...
by ag123
Sat Oct 17, 2020 7:25 pm
Forum: Off topic
Topic: charging lipo batteries
Replies: 12
Views: 1007

Re: charging lipo batteries

Thanks Ray I'd guess I'd check out LiFePO4 batteries sometime. For now as I bought a couple of cheap18650 batteries (accordingly likely the worse in terms of safety) and some solar cells, I think I'd hack something out with a mosfet and STM32 :D Among the considerations there's 2 pieces of non linea...
by ag123
Sat Oct 10, 2020 2:27 pm
Forum: Off topic
Topic: charging lipo batteries
Replies: 12
Views: 1007

charging lipo batteries

i stumbled into an interesting resource panasonic lithium ion batteries https://industrial.panasonic.com/ww/products/batteries/secondary-batteries/lithium-ion/models/NCA103450 what is interesting is the app note found on the related info links https://industrial.panasonic.com/cdbs/www-data/pdf/ACA40...
by ag123
Mon Oct 05, 2020 2:42 pm
Forum: Off topic
Topic: How to use STM32 boards with Arduino IDE and how fast ESP32 vs STM32 are they? (incl. surprise)
Replies: 7
Views: 640

Re: How to use STM32 boards with Arduino IDE and how fast ESP32 vs STM32 are they? (incl. surprise)

on another note if you watch the video, you can see the performance of the F4 FPU, in single precision mode in which FPU is effective it out performs all the others compared. Frankly, this is an underutilized feature on the F4. I've been thinking about using this feature in 'sensor' use cases, a coi...
by ag123
Mon Sep 28, 2020 2:59 pm
Forum: Off topic
Topic: How to use STM32 boards with Arduino IDE and how fast ESP32 vs STM32 are they? (incl. surprise)
Replies: 7
Views: 640

Re: How to use STM32 boards with Arduino IDE and how fast ESP32 vs STM32 are they? (incl. surprise)

as for myself, STM32 is still my fad as i'm kind of lazy to learn another mcu, but i'd guess i'd checkout the esp32 soon :lol: i'd guess STM32 is good for the things it is good at while ESP32 is good for the things it is good at e.g. wifi embedded. STM32's DMA is very hard to beat where it comes to ...
by ag123
Fri Sep 25, 2020 6:10 am
Forum: Off topic
Topic: How to use STM32 boards with Arduino IDE and how fast ESP32 vs STM32 are they? (incl. surprise)
Replies: 7
Views: 640

How to use STM32 boards with Arduino IDE and how fast ESP32 vs STM32 are they? (incl. surprise)

How to use STM32 boards with Arduino IDE and how fast ESP32 vs STM32 are they? (incl. surprise)
https://youtu.be/337rDuCGeYs
by ag123
Fri Sep 11, 2020 5:32 pm
Forum: General discussion
Topic: Portenta H7
Replies: 7
Views: 560

Re: Portenta H7

...this can probably run a full blown PDA or mobile style OS it has high speed usb, it is a plus as compared to the full speed ones for the 'lower' devices Very interesting. Some (all) will likely be sold to folks that can voucher the expense back to their business. This is the kind of thing you wo...
by ag123
Thu Sep 10, 2020 12:13 pm
Forum: General discussion
Topic: Portenta H7
Replies: 7
Views: 560

Re: Portenta H7

it is rather interesting quite a few stm32h7 boards are showing on aliexpress
https://www.aliexpress.com/wholesale?ca ... xt=stm32h7

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