Open Kontrol Gateway - emonBase

For a while now we have been using the NanodeRF as our emonBase web-connected base station. The NanodeRF is great and has met our needs well. However using the ENC28J60 Ethernet chip does have some limitations.

We have through about having an emonBase option which supports the Wiznet Ethernet chip. This is the chip that is used in the official Arduino Ethernet. On the Wiznet chip the TCP/IP stack is implemented on the chip as opposed to on the ATmega328 as in the case of the ENC28J60, this means ATmega328 has a greatly reduced load, more application memory is freed up and the code is much simpler and brought in line with the Arduino Ethernet code examples.

In testing we have found the Wiznet chip to be more stable at holding a connection over a long period.

However the Wiznet chip is more expensive than the ENC28J60, what we need is a flexible emonBase unit which is interchangeable between the two Ethernet chips, enter the Open Kontrol Gateway (OKG)!




The OKG is a very flexible web-connected base station based on the ATmega328 which is totally Arduino IDE compatible (Arduino UNO bootloader). The OKG has been designed and manufactured by our friend Miles who runs Ciseco Plc.

The OKG PCB supports multiple wireless options such as RFM12B, XBEE, XRF, RN-XV Wifi. There is also PCB footprints for expansions like a RTC, SD card and SRAM. Finally what attracted us to the OKG was the ability to easily choose between the ENC28J60 or Wiznet Ethernet chips:

OKG ENC28J60 module

OKG Wiznet W5200 module 
We now have stock of the OKG in kit form in the OpenEnergyMonitor shop. The kits will come with an RFM12B wireless radio (choice of frequency) and a choice of ENC28J60 or Wiznet Ethernet chips.

The OKG with the ENC28J60 is almost hardware identical to the NanodeRF. NanodeRF emonBase sketches will run on the OKG with a couple of little changes.

See the OKG OpenEnergyMonitor wiki page for the changes required to make the OKG work with the RFM12B and OpenEnergyMonitor emonBase examples:

http://wiki.openenergymonitor.org/index.php?title=Open_Kontrol_Gateway

Note: The wiki is still in beta, we will blog more about it once it's been a bit more polished. It's our hope that by using a Media Wiki for our more technical documentation people will be more inclined to contribute corrections and additions and the documentations should be easier to organise and maintain. The OpenEnergyMonitor login should automatically log you in to the wiki. Just make sure your logged into the OpenEnergyMonitor website before opening up the wiki page. Try clearing your browsers cookies if this doesn't work first time.

We are now stocking the OKG in the OpenEnergyMonitor shop: http://shop.openenergymonitor.com/open-kontrol-gateway/

What about the Raspberry Pi!? 
Don't worry we haven't overlooked the Raspberry Pi! We have successfully had emoncms running on a Pi receiving RFM12B data from a USB JeeLink, we plan to blog more about this soon. We're currently with Martin Harizanov to make a RFM12B to Raspberry Pi GPIO expansion board. The Raspberry Pi will make a very powerful emonbase/home energy server however it's quite a complicated little beast for beginners who have limited linux knowledge. We think there is still a need to also have a simpler Arduino based emonBase option such as the NanodeRF or OKG. To engage in discussion regarding this post, please post on our Community Forum.