I'd love to discuss design philosophies and even detailed component choices, but I'm not comfortable releasing any software, PCB designs or schematics at this point. People would end up inherit my bugs and also, if not flawed but at least sub-optimal designs. There are some issues and minor problems with most of the components, and this will be an ongoing process to go back and fix. I am in fact already in the process of redesigning the remote engine monitor box. There will be more use of galvanic isolation, using analog optocouplers for instance. Also, the box would have access directly to the data bus. Then the display unit will be redesigned with a larger screen -- same as the EFIS. The current 4.3" is a bit tiny to cram this much information into it. Which in turn means a whole new instrument panel.... It never ends!Ebbe, I love what you've done and it seems to be leagues above amateur level. Arguably, the engine monitoring system is the single most important avionics to promote safety and reliability of a flying experimental aircraft. Yet, even the non certified EMS units out there are far more expensive than I think they need to be. So, my question is that given your experience with your DIY EMS, how inexpensively could such a system be built? If you were going to open source any of your components, my priority interest would be for an EMS (that can also record the channels).
I'd like to know builders philosophies on how to hook up dedicated EMS systems like JP or GRT. Do you wire it outside of the avionics master, so you have the instrument on while cranking? If that instrument were your only indication of oil pressure, I would prefer to have it on during the starting process. I would assume they take a little while to start up? Mine starts up in ~2 seconds, from power-on to correct data, so I could technically turn it on afterwards. Of course it has to be properly hardened against voltage spikes, but that goes for all components.
Happy Easter!
- Ebbe