AX05B I Meas Current Measurement Leaf

Top	Bottom

Features

Leafony AX05B I Meas is a leaf for measuring current on the V33 and VBUS lines of the Leafony Bus. It separates each power line into IN and OUT so an external current measurement instrument, such as the Nordic Power Profiler Kit II (PPK2), can be inserted in series.

It separates the power supply connections of the leaves stacked below AX05B from those stacked above it, allowing you to measure the current flowing to the upper leaves.

Each power line coming from the lower leaves is split into IN and OUT on AX05B. Connect the current measurement instrument in series on the line you want to measure, and short IN and OUT with a jumper on the line you are not measuring.

• Supports current measurement on the Leafony Bus V33 and VBUS lines
• Provides 2.54 mm pitch right-angle pin headers for both V33 and VBUS
• Power lines that are not being measured can be shorted with jumpers for normal use

Specification

Item	Description
Dimension	W20×D20mm
Board thickness	0.8mm
Layer	2 layers
Surface finish	ENIG (Immersion gold)
Bus connector	Leafony Bus (F29/B29)
Measurement connector	1×4, 2.54 mm pitch, right-angle pin header ×2

Package contents

AX05B I Meas includes the board, two single-row four-pin right-angle pin headers, and two jumper pins.

Board	Included parts

Measurement connector

J1 is for V33, and J2 is for VBUS. Both connectors use the same pin assignment.

Pin	J1 (V33)	J2 (VBUS)	Use
1	GND	GND	Measurement instrument GND
2	V33OUT	VBUSOUT	Current flowing out to the top side of the leaf
3	V33IN	VBUSIN	Current flowing in from the bottom side of the leaf
4	GND	GND	Measurement instrument GND

Current measurement with Nordic Power Profiler Kit II

The Nordic Power Profiler Kit II (PPK2) is a current logger that can measure both the tiny currents drawn by low-power IoT devices during sleep and the milliamp-level currents drawn while they are active. It can also operate as a source measurement unit (SMU), providing power while measuring current.

This makes it a useful tool for developing battery-powered IoT devices, including Leafony applications.

Follow these steps to measure current with the PPK2.

1. Solder the included single-row four-pin headers onto the leaf as shown below.

   

2. Connect the PPK2 pins to the V33 connector as shown in the table. To insert the PPK2 as an ammeter in series with the power line, connect VIN to V33IN and VOUT to V33OUT.

   PPK2	AX05B J1 (V33)	Use
   GND	GND	GND
   VIN	V33IN	Power coming from the lower leaves
   VOUT	V33OUT	Power going to the upper leaves
   GND	GND	GND

   

   

   Place AX05B between the lower leaves and the upper leaves you want to measure. The V33 supply from the lower leaves passes through the ammeter connected to AX05B before reaching the upper leaves. When using a single ammeter, such as the PPK2, short the unmeasured VBUS line with a jumper pin so that power reaches the upper leaves.

3. Since VBUS is not being measured in this example, short VBUSIN and VBUSOUT with one of the included jumper pins.

4. Assemble the stack with the leaves whose current you want to measure above AX05B and all other leaves below it.

5. Turn on the power, operate the PPK2 in ammeter mode, and click Start to begin measuring current. In the Power Profiler app, this mode is called Ampere meter, as shown in the official PPK2 quick start.

For information on using the PPK2, see the official page (Japanese).

Documents

• GitHub repository
• KiCad project
• Schematic (PDF)
• PCB layout (PDF)
• Schematic (KiCad)
• PCB layout (KiCad)
• Panelized manufacturing data

Revision history

• June 2026: First edition