This week our new boards arrived. After a bit of grief due to picking a faster crystal than what Atmel/Microchip guarantees will work at 3.3 Volt, we managed to cobble together a test this Saturday evening. Things are looking promising, especially our new rotor grounding method. We shall see how well it works after some more rigorous testing.
There are more things that remain to be seen. For example, we’re hoping the improved shielding in our new fieldmill PCBs will reduce/eliminate how much of any synchronous unwanted signals we pick up. Previous versions would pick up the voltage changes in the IR tachometer signal, from several centimeters away. This because when measuring with 100 MOhm transimpedance amplifiers, any stray dV/dt’s get picked up. If they’re in sync with the rotor’s rotation then that pickup appears as an undesired offset in our signal!
Besides the minor crystal issue, we’ve so far not had much problems with the PCBs. We’re currently focusing on mechanical and software issues, both of which are important for final integration with the lander. Hopefully more on that in the future! For now we’re aiming for more vibration testing at the start of 2019.