With the I2C multiplexer, it is possible multiple I2C slaves with the same bus address to connect to the I2C bus.
About the control register can be switched between the four bus segments. The selection of the channel via the I2C-bus. So it is thus possible, for example, several temperature humidity sensors, for example, Sensirion or HYGROCHIP HYT 271 read with the I2C bus.
In the double-sided printed circuit board with 42 x 64 mm, the I2C block PCA 9544, terminals for each bus line and the resistors housed for termination of the four bus lines.
The SMD chip in SO-20 housing can be well soldered by hand on the tin-plated circuit board. Who the trusts do not own, you can order the kit also with pre-PCA 9544. Furthermore, the circuit board can be fitted as with all DIN rail modules with either fixed or plug-in terminals.
What is the difference between the I2C multiplexer PCA9544 and PCA9545 I2C switch?
- The multiplexer has three address, the switch only two. - A maximum of eight multiplexers are connected to one master. - With Multiplexer is always switched through only one channel.
On all four channels (inputs) is also the INT signal. Once connected slave pulls the INT signal on one channel at low this will be indicated at the output and then "passed through" to the master. He is practically a ORing all four INT-channel inputs.
About the register can now be found in the program which of the four channels has triggered the interrupt.
At the three address jumpers the I2C slave address can be set. It can be operated on a master that is up to eight I2C multiplexer.
PCA9544A: 224, 226, 228, 230, 232, 234, 236, 238
The multiplexer can also be used for level matching between different bus voltages. In the data sheet for PCA9544A allows voltage level translation is between 1.8 V, 2.5 V, 3.3 V and 5 V buses. To do this, unplug the termination jumper of the corresponding channel and terminate on the slave with 4,7kOhm resistors to + 1.8V, 2.5V 3.3V.
Dimension of the printed circuit board 42 mm x 63 mm
Kit I2C switch for DIN rail mounting
The I2C switch it is possible to switch four I2C buses in any combination to a master.
Also its possible multiple I2C slaves with the same bus address to connect to the I2C bus.
Kit I2C I2C-RS232-Modem 2 for DIN rail
With this modemyou can control or read I2C slaves via the serial RS232 interface. The baud rate adjustable via PC software.
Command Set is the same as the I2C-USB modem
Digital I2C input card with optocouplers 8-bit 5-24V for DIN rail
The I2C input module can be used to read 8 digital signals from 2.5V to 30V via the I2C bus.
The inputs are galvanically isolated with optocouplers