Raspberry Pi

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Hardware (RFM12Pi)

 
 

With the addition of an RFM12Pi expansion board to receive data via wireless from other OpenEnergyMonitor modules such as an emonTx energy and temperature monitoring node or an emonGLCD display. A Raspberry Pi used to forward data to an emoncms sever (standard SD card image) or/and log data locally to an SD card or connected Harddrive.

  

RFM12Pi Adapter Board

Technical hardware documentation wiki:

RFM12Pi V1 (old)

RFM12Pi V2 (SMT - current design)

Open Hardware designs: Download the RFM12Pi Schematic, PCB Eagle CAD files from Github: github.com/mharizanov/RFM2Pi. The hardware designs are released under the Creative Commons Attribution-ShareAlike 3.0 Unported License

Arduino compatible: The RFM12Pi uses an ATmega328 which comes pre-loaded with Arduino compatible firmware. New firmware can easily by uploaded directly from the Pi via the serial uploader. See the technical documentation wiki.

Software

  • New, in testing: How to setup a raspberrypi running emonhub + emoncms (low write version)
    This is an all in one solution with which can be used to either forward data to a remote server such as emoncms.org or log and view data locally. It can be used with an SD card (long term lifespan still in testing) or Harddrive. It uses the latest version of emonhub which replaces the oem_gateway.

Note: SD Cards have a limited lifespan, the Individual flash memory cells can only be written to a limited amount of times (~10,000x for MLC). It can be quite easy to reach this number of writes when data logging at regular intervals. When we first ran emoncms on SD cards the lifespan was surprisingly low (~ 3 months) and so we switched to recommending using an external harddrive for local datalogging. Since then further development work on emoncms has reduced the write load significantly 30 to several 100x and the data that is written is appended which should reduce the amount of repeated writing to the same sectors. We are therefore testing again using SD cards for local logging with a new low write version of emoncms and other setup changes like read-only OS partition and ext2 - non journaling data partition with a reduced sector size.