AC09 Cat-M1 TY

These photos show the AC09 board. The front side has the Cellular LPWA Cat-M1 module and external antenna connector; the back side has the nanoSIM slot.

Features

This Cellular LPWA Cat-M1 leaf is intended to provide cellular data communication for IoT devices when combined with a processor leaf. The Google Sheets example for the Cat-M1 Kit’s AP03B + AI05 configuration includes SIM and endpoint settings. Distinguish the example requirements from product-wide operator support and guaranteed operation.

AC09 Cat-M1 TY uses a Taiyo Yuden WSCLxADAH2Z-series cellular LPWA module.

• Communicates with the module over UART. An I2C I/O expander controls the power-button, shutdown and wakeup signals.
• Includes a nanoSIM slot, an onboard chip antenna and a U.FL connector for an external antenna.
• The module supports low-power operation with eDRX and PSM. See Taiyo Yuden’s product information (Japanese) for details.

Module, antenna connector and SIM slot locations

1. Communication module (front). Provides Cellular LPWA Cat-M1 communication.
2. External antenna connector (front). This is a U.FL connector. See Antennas for the conditions for selecting the onboard or external antenna.
3. nanoSIM slot (back). This slot accepts a nanoSIM compatible with the cellular service you use.

Click the diagram to enlarge it. Arrows identify the components; they do not show the SIM insertion direction. See Cat-M1 Kit development preparation for SIM and endpoint settings.

Specifications

Item	Description
Cellular LPWA Cat-M1 module	Taiyo Yuden WSCLxADAH2Z series
Communication technology	Cellular LPWA Cat-M1
Power input	Leafony Bus 3.3V terminal (pin 1)
Host interfaces	UART (TX/RX, RTS/CTS), I2C (control)
UART level shifter	TXB0104RUTR (3.3V / 1.8V)
I/O expander	PCAL6408AHKX
I2C address	0x21 (7-bit notation)
SIM card	nanoSIM (Molex 1042240820 slot)
Onboard antenna	STAF 1019-085A
External antenna connector	Hirose Electric U.FL-R-SMT-1(10)
Board dimensions	23 × 38.7 mm (design dimensions, excluding component height)

Product specifications, including the exact module part number, the full range of supported bands and operators, and current consumption, will be announced once confirmed. The related example describes 1NCE and SORACOM settings; it does not guarantee operation with every SIM, region or leaf configuration.

Power and control

The Leafony Bus 3.3V terminal supplies the module’s VBAT input. An onboard TPS61021ADSGT generates the RF power supply (VBAT_FEM), and a TLV71718PDQNT generates the 1.8V signal-circuit supply (VDDIO).

The module’s power state is controlled through the I/O expander. The published sample uses AV06 as a battery-powered configuration example. Also see the power-supply Q&A.

Pin assignment

Click the diagram to enlarge it. MCU denotes the processor leaf, and arrows show the direction of UART signals. RESET and INT_N are the reset and interrupt signals of the PCAL6408A I/O expander.

Select AC09 in the Pin Assignment Editor to edit the same diagram and save it as PNG or SVG.

The following table lists the main Leafony Bus signals used by AC09. UART directions are shown from the processor leaf’s perspective.

Pin	Leafony Bus signal	AC09 connection or function
1	3.3V	Power input (VBAT)
5	RESET	I/O expander reset
7	D6	UART input: receives the module’s RTS signal (processor CTS)
11	D8	UART transmit: connects to the module’s RX
13	D9	UART receive: input from the module’s TX
22	D2	I/O expander interrupt output (INT)
23	SDA	I2C data
25	SCL	I2C clock
26	D4	UART output: sends to the module’s CTS (processor RTS)
27	GND	Power and signal ground

I2C address

The I/O expander address is 0x21. AC08 Mary and AC04 King M use the same address, so connecting these leaves to the same I2C bus causes an address conflict. Check the I2C address map when combining leaves.

Antennas

The board is designed to select either the onboard chip antenna (ANT1) or the external antenna U.FL connector (CN3) through the JP1 connection.

JP1 connection	Antenna used
1–2	Onboard chip antenna (STAF 1019-085A)
2–3	External antenna connected to CN3

Supported antennas and certification conditions will be announced once confirmed. Documents about antennas covered by the module’s certification are available under “Reference アンテナ一覧” on Taiyo Yuden’s product page (Japanese). User registration is required.

Development environment and samples

The PlatformIO projects in the AC09 development repository contain development code using STM32 MCU leaves and the Arduino framework. See Documents for repository access requirements.

Project	Purpose and configuration
google_sheets	Uses the Cat-M1 Kit’s AP03B + AI05 to read BME280 temperature and humidity and record them in Google Sheets. Select environment leafony_ap03b
http_get	Checks HTTP communication with AP03
mqtt_thingspeak	Sends AP03 + AI01 measurements to ThingSpeak over MQTT

Check each project’s README for settings and required software.

For AT command specifications, see the “AT command manual (Light Version)” on Taiyo Yuden’s product page (Japanese). User registration is required.

Related samples

• Save temperature and humidity data to Google Sheets with AC09 Cat-M1 TY: Uses AP03B to read temperature and humidity from the AI05 Env Sensors leaf and record them in Google Sheets. The Docs guide sets the transmission interval to 10 minutes; the GitHub development template uses 30 seconds.

Cat-M1 Kit development preparation covers assembly and sample settings.

Documents

The design and development repository is currently private. Access to the following GitHub documents requires signing a separate non-disclosure agreement (NDA). Please contact us (Japanese) for details.

• AC09 design and development repository
• KiCad design data (schematics and board)
• Schematic (PDF included in the repository)
• Bill of materials (manufacturing BOM)
• Taiyo Yuden cellular LPWA Cat-M1 product information (Japanese)

Revision history

• September 2026: Added the AC09 page.