In the interest of a public discussion for those interested, we’ve been discussing STM32 hardware configurations in a PM.
Early on in the thread Robert Wall posted
Paul Burnell then replied (excerpt from the post):
I mentioned my wish to have a MBUS reader module to integrate heatpump monitor development efforts and the option to directly mount a RaspberryPi3.
Later on Paul asked the question in relation to discussion regarding 64 vs 144 pin stm32f303 package:
I made a list of the main options I could think about:
- Single phase, whole house: 1V + 1CT
- Single phase, solar: 1V + 2CT
- Single phase, solar, EV, heat pump, import/export: 1V + 4CT
- Single phase, total number of used circuits in my distribution board: 1V + 7CT’s
- Three phase, whole house: 3V + 3CT
- Three phase, solar: 3 + 6CT
- Three phase, solar, EV, heat pump, import/export: 3V + 12CT
Paul then replied with an extended discussion, targeting 15-18CT’s:
Paul and Robert reinforced the point that the solution needs to be modular.
We discussed a little on enclosures, the need to find an enclosure approach that could accommodate a potentially modular + stackable approach.
Then in trying to get a better picture in my head of how this could work, I sketched up the following ideas. From left to right you have a baseboard with the STM32 core (likely 144pin STM32F303ZE), the baseboard has a good number of CT’s (perhaps 6), ACAC input, temperature and pulsecounting. The baseboard could then be extended with shield-like boards that access further IO on the baseboards STM32 core. The second board from the left shows a shield with 12 CT’s and 2ACAC inputs. The same result could perhaps be achieved with two smaller 6 channel CT boards and two connector rows (right top & bottom):
More to follow…