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PiSupply / PiJuice

Resources for PiJuice HAT for Raspberry Pi - use your Pi Anywhere
https://uk.pi-supply.com/collections/pijuice/products/pijuice-portable-power-raspberry-pi
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GPIO power input : weird values of current #872

Open plafond75 opened 2 years ago

plafond75 commented 2 years ago

Hi everyone, I just started using the Pijuice with a RPi 3B+ and the battery shipped with it (BP7x 1820mAh).

The battery profile selected in the pijuice configuration menu is BP7X_1820

The Pijuice's micro-usb is plugged to a power supply that can output 5V; 2.5A.

From the pijuice_cli panel, I can see that the current flowing from the pijuice to the RPi oscillates between 1.34A and 2.44A. What does that exactly mean...? At the time of writing, the battery is at 97% of charge; and my power supply indicates a 0.55A output (at 5.2V)

How should I interpret the value I'm reading from the pijuice_cli panel ?

FYI, I'm using a RPI 3B+ with a fresh install of raspbian 9.8 (stretch) without GUI (console only) and i'm using ssh (no HDMI). Nothing is plugged to the RPi except a RJ45 cable.

Pijuice SW version : 1.7 Pijuice FW version : 1.5

tvoverbeek commented 2 years ago

The current to the Pi via the GPIO 5V pins is not coming directly from your power supply. The power input goes to the charging controller chip which uses part for charging and has a voltage converter producing 3.3V for the MCU and a Vsys output which goes to yet another DCDC converter which produces the 5V. The current you see in the cli is an estimate. There is no direct current measurement on the PiJuice.

You are using an old version of raspbian which does not receive any updates any more. Current version is bullseye (Debian 11) and the pijuice packages are at 1.8 (available for buster (Deb 10) and bullseye (Deb 11). Suggest you update if possible.

plafond75 commented 2 years ago

Thanks for the precisions ! When you say that the current shown in the cli is an estimate, it means that it's computed through an algorithm ? There is no current gauge implemented on the pijuice ? And for the debian version, unfortunately, I can't upgrade to Bullseye right now for my project, but I'll try with another RPi running bullseye to compare :-) Thanks again !