Wi reless M-Bus-EK

2

Rev. 0.1

3. Hardware Overview

The Wireless M-Bus Demo board has two sections. The Wireless M-Bus meter section is on the right half as

shown in Figure 2.

Figure 2. Meter Section

The Wireless M-Bus meter section includes the following components.

The C8051F930 is well suited for Low-Power Metering solutions. This MCU includes 64 k of Flash and 4 k of RAM,

which is sufficient for the Wireless M-Bus stack and a large application. The C8051F930 has a very low-power

Sleep mode. The current consumption in Sleep mode is only 50 nA. The MCU also has a 32.768 kHz

868 MHz band used by the Wireless M-Bus Standard. The RF layout is matched for 868 MHz. The Si4431 is

placed in Shutdown mode when the radio is not in use. The current draw in shutdown mode is only 15 nA.

The CP2400 LCD driver features an SPI interface and can drive displays with up to 128 segments and four

backplanes. The Wireless M-Bus meter section uses a static four-digit display for the lowest possible power

consumption. The Meter Display is used to display either pulse count or Temperature. The Monitor Section is

shown in Figure 3.

C8051F930

CP2400

Si4431