I2C extender - Long distance I2C - PoBlog™

PoLabs proudly announces “We have I2C extender available!”

Since we receive a large number of our customers’ requests for a long distance I2C communication, we have decided to satisfy wishes of our loyal and valued customers. Therefore we made a new general purpose product I2C extender. Super usable I2C extender fixes issues with I2C communication over long cables fast, easy and reliable.

First of all, let us introduce just a few facts about I2C bus. In general we use I2C bus for communication between microprocessor and peripheral on PCB boards where physical distances are relative short. Common I2C bus speeds are: standard mode (100 kb/s) or the fast mode (400 kb/s). Capacitance between bus wires determinates the bus speed limit and is proportional to a cable length. As the cable length increases the capacitance is getting higher and so I2C communication begins to fail.

With this in mind, our new product solves issues regarding cable length.

How to connect I2c extender

Now, with the I2C extender, our CNC keyboard – PoNETkbd48CNC could be mounted at the control panel in a distance from a CNC controller equipment. Therefore, you can do your installation super fast and effortless. In these case, just connect the extender at the PoKeys57CNC USB and Ethernet controller board side and the extender at the PoNETkbd48CNC side. Use the ribbon flat cable between them and you are ready to communicate with your keyboard. No additional setup!

Figure 1: PoNET I2C ExtenderFigure 2: Pinout

Additionally, you can use extender for PoSensors2 connection or any other I2C bus based device. In order to be universal, there are two types of popular standard connectors available on the standard I2C bus side. Connectors are in parallel.

Figure 3: A typical test setup

As an example, using I2C extender and 5 m cable in a case where a light sensor must be outside on a day light and a processor unit is inside the house. Figure 3 shows using different type of connector options on the standard I2C bus side.

Also if you need informations about the stepper motor – complete explanation.

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