USB Charger Doctor - In-line Voltage and Current Meter
Help! This patient is heating up! Is the voltage too low? Is the current draw too high? Is there a doctor in the house? Oh, thank goodness, the Charger Doctor is here! Right on time...Doctor, can you tell us what the current draw is? What about the voltage? Thanks to the Doctor,…
Pinout
- USB-A plug VBUS
USB upstream power input measured by the Charger Doctor. Adafruit states the dongle plugs between a USB device, supports 3.5-7VDC input, and has a 0.05 ohm resistor in line with the power pin to measure current draw.
Type · powerVoltage · 3.5-7VDC input range from Adafruit product page; normal USB devices usually hover around 4.75-5.25V per source. - USB-A plug GND
USB upstream ground/reference for the inline USB power meter.
Type · ground - USB-A plug D+
USB upstream data line passed through by the inline meter. Adafruit states the device passes the data lines through and supports USB 1.x and 2.x data speeds.
Type · signal - USB-A plug D-
USB upstream data line passed through by the inline meter. Adafruit states the device passes the data lines through and supports USB 1.x and 2.x data speeds.
Type · signal - USB-A receptacle VBUS
USB downstream power output to the connected device, monitored for voltage and current by the inline meter.
Start wiring
SPI · 3.5-7VDC input range from Adafruit product page; normal USB devices usually hover around 4.75-5.25V per source. · 3.5-7VDC working range, up to 3A current, from Adafruit product page.
Verify supply voltage and logic levels before powering up.
Module pins: USB-A plug VBUS, USB-A receptacle VBUS, USB-A plug GND, USB-A receptacle GND, USB-A plug D+, USB-A plug D-, USB-A receptacle D+, USB-A receptacle D-. Schematik maps them to your board in the app.
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