Boron LTE w/ Solar- Trials

I concur, I was just reading the Datasheet and it explains it well (and so did you).

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Cool, glad it was helpful :sunny:

From the Datasheet: Dynamic Power Management
To meet maximum current limit in USB spec and avoid over loading the adapter, the bq24195L, bq24195
features Dynamic Power Management (DPM), which continuously monitors the input current and input voltage.
When input source is over-loaded, either the current exceeds the input current limit (REG00[2:0]) or the voltage
falls below the input voltage limit (REG00[6:3]). The device then reduces the charge current until the input current
falls below the input current limit and the input voltage rises above the input voltage limit.

Why cant we set the Register Bits specifically for a panel's Max Power (current & voltage) or up to the 5.08V Voltage Limit?

Good question.

I couldn’t get it to set higher than the 4.84v for some reason, if you can get it to 5.08v then that would be better.

There is a old thread on here where I have the PMIC settings from the Particle firmware and the 4.84v was the best setting available. I’ll try to find it.

Not saying 5.08v is not possible so please do try to get it there.

Here you go.

Starting at line 87 basically what is shown in your chart.

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Line 193 has it… ready for 5.08V max

        case 5080:
        writeRegister(INPUT_SOURCE_REGISTER, (mask | 0b01111000));
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Now we both learn something today :smiley:

So now we use?


Hahaha, you're asking the wrong guy. I was hoping somebody would chime in for some reassurance.... but i think so, for Solar Power Only (maybe)

It appears that Register 03 wasn't included......So my wish for pmic.setTermChargeCurrent(0,0,0,0) just got shot in the foot.


Maybe @ScruffR or @rickkas7 can help us, rookies, out here :smile:

Yes Please......maybe once they stop laughing at us :woman_facepalming:

Hi guys @Rftop @RWB
I am trying to publish fuelgauge on the Boron

          "Volts:" + String::format("%.2f",fuel.getVCell()) + 
          ",SoC:" + String::format("%.2f",fuel.getSoC()),
          60, PRIVATE

but I am getting different readings in Console.
Does this make sense?

Just one comment about your use of String()
Apart from the general advice to not use String unless it’s absolutely unavoidable, when you are using String::format() already, there is no use whatsover in also concatenating multiple strings.

Rather go with this

                  , String::format("Volts:%.2f,SoC:%.2f", fuel.getVCell(), fuel.getSoC())
                  , PRIVATE

I’m planning on running my Borons on Voltaic 6V6W panels with a 4400 mAh Adafruit LiPo on weather stations which will never sleep. It seems from this thread inserting some sort of LiPo Solar charging break out ie adafruit or DF Robot would only add extra cost and I would take a hit on efficiency.

But I’m confused about the USB PORT and VUSBPIN

USB PORT says provide at least 500 mA. However in VUSB PIN it says to NOT exceed 500mA. The voltaic panels have a stated max ouput of 930 mA. Both the Adafruit and DF Robot chargers can limit to 500 mA. I am currently using a 2.2k resistor to up the output of the Adafruit charger to ~980 mA as the LiPo I’m using has a max rating of 1A to power my Electrons. I will be exchanging some of those and installing more with Borons.

I keep chasing my tail so any suggestions would be MUCH appreciated.


@Mister, take a look here. I believe a fix to the documentation has been posted.

I saw the post from @ninjatill but I’m still confused about the two sentences which seem opposed to each other which I highlighted. One says to make sure USB port is supplied at least 500mA and the other says to NOT exceed current rating of the USB port rated at 500mA.

I’m very happy to be wrong I just don’t understand how these statements in the Docs can both be right.

@ninjatill did clarify the voltage issue from the USB Port and for that I thank him. :sparkler::sparkler:

When the Boron is powered via USB, and Vusb is used as an output to power a peripheral, the Vusb port will output 4.5-5v and the output current is limited to the USB port specification. USB v2.0 and prior ports are limited to 500mA. USB 3.0 and newer may supply more current but are not required to. So, if you account for the power draw of the Particle device, you can pull about 450mA from the USB port.

When Vusb is used to power the Particle Device, then the voltage is limited to less than 12V. There’s no limit to the current, the Particle Device will pull what it needs. You have to make sure your external power supply will meet the current demands of the Particle Device and whatever peripherals are also powered by the external supply.

I added a pull request to update the Boron docs to add the “input” scenario.

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A bit of clarity here. Actually, the Vin pin is connected to the Vusb input via a reverse-voltage protection diode. This diode prevents damage to the powering USB supply when the Boron is also being powered via Vin. It is the Vin pin that should be used to power the Boron with 3.9V to 12V.

Thanks @ScruffR for the tip!
Any idea why there is a difference in the SoC between the publish and the console?

@peekay123, I agree. But only the datasheet block diagram shows Vin. The silkscreen on the device only shows Vusb. I can see how it’s confusing since Gen 2 had a Vin pin which better indicates the intent of the pin IMHO.

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I feel like I’m Hi-Jacking this thread… if I knew how to fork it I would.

@ninjatill I see now on the block diagram vusb/vin going directly to the BQ24195.

This section on power has also been confusing to me. Both sections list Supply Input Voltage but Max ratings and recommended ratings have 1) different pins listed and 2) different max voltages listed.

Not sure what a pull request is but some clarification from Particle here might be helpful as well. I’m not an engineer, CS whiz or programmer so understanding these docs can be quite difficult.