We decided to fall back to engineering breadboard model phase. Right now we have two identical systems: a flight model and an engineering model. We use the engineering model for system tests because its layout makes easier to add testpoints and diagnostic lines.
This is the flight model (in flight configuration):
And this is the engineering model (in breadboard configuration):
So far we found some RF disturbance from the APRS affecting the supply lines and the EPS. We fixed it by placing the VHF antenna further from the flight computer, also we made a better quality antenna to minimize the RF disturbance.
We had some issues with the configuration of the UHF RF transceiver at low frequency deviation. We recalculated our RF properties and we would fit in the legal range of the radio regulations with our new values too.
The UHF communication module got a new firmware. Right now we are testing two versions of this firmware, each use a different library to interact with the RF transceiver chip.
So right now bench tests are on their way and we are preparing for the cooling chamber tests.
We added the cable harness of the project to the cooling chamber, so we could read diagnostics, internal bus transmission and RF properties. Also we are going to install a humidity sensor to the chamber. This will be only a control display beside the temperature sensor we already installed earlier.
The cooling chamber is nothing fancy, an old fridge with extra insulation and some minor modification. I hope I could post some pictures of it soon, but our workshop was a mess lately so I couldn't shoot fine pictures.