User's Guide

Review Copy 11-6-10

ThingMagic Micro Family Guide

www.JADAKtech.com

Control Signal Specification

The module communicates to a host processor via a TTL logic level UART serial port or via a USB port.

Both ports are accessed on the Molex connector or edge side-pads. The TTL logic level UART supports

complete functionality. The USB port supports complete functionality, except the lowest power operational

mode.

NOTE: Power Consumption specifications apply to control via the TTL UART.

NOTE: It is not recommended to use the TTL interface when planning to operate the module in Tag

Streaming/Continuous Reading mode. The TTL interface (both the module side and the host side)

cannot detect physical disconnections, unlike the USB Interface, simplifying reconnection.

TTL Level UART Interface

TTL Level TX

• V-Low: Max 0.4 VDC

• V-High: 2.1 to 3.3 VDC

• 8 mA max

TTL Level RX

• V-Low: -0.3 to 0.6 VDC

• V-High: 2.2 to 5 VDC

A level converter could be necessary to interface to other devices that use standard 12V RS232. Only three

pins are used for serial communication (TX, RX, and GND). Hardware handshaking is not supported. The

Micro serial port has an interrupt-driven FIFO that empties into a circular buffer.

The connected host processor’s receiver must have the capability to receive up to 256 bytes of data at a

time without overflowing. (256 bytes is the maximum data packet size.)

Supported Baud Rates

• 9600

• 19200

• 38400

• 115200

• 230400

• 460800

• 921600

NOTE: The baud rate in the Boot Loader mode depends on whether the module entered the bootloader

mode after a power-up or through an assert or “boot bootloader” user command. Upon power

up if the Reset Line is LOW then the default baud rate of 115200 will be used. If the module returns

to the bootloader from Application Firmware mode, then the current state and baud rate will be

retained.