a very cool project.
I decided to build this work myself, there is very good support. The PCB is already ordered, but what is the problem as you know is not the chips.
Specifically, you can’t get them anywhere:
maybe someone has other experiences.
Tell me about it. For those not familiar with the part numbers, those are the real-time-clock and associated 32.768 crystal. They are simply no longer available. I’ve had to find a solution for new units in manufacturing now.
The M41T81 is another i2c SOIC8 clock that is electrically compatible as far as footprint and pinout, and also uses a 32.768 crystal. It works pretty much the same as the PCF8523 except that the interface is different. IoTaWatt release 02_06_06 recognizes the M41T81 and has been modified to work with it. It should also work with the M41T81S which is the latest version. The difference is that the S supports battery-low indication.
For the crystal, there are a few alternatives, especially if you only need a couple. It is a 32.768KHZ crystal. Match the specs with another brand: 4-SOJ, 5.50mm pitch, 12.5pF, 50K ohms (although up to 70K should work).
As far as the D1213A-04SO-7 is concerned, those are TVS protection diodes. The ADC are good for 5kV, the diodes just take it up to 6 kV to pass some CE tests. For a DIY, you can just leave them off.
I’m looking, incredible support!
You know, I’m a simple electrician - the one who pulls thick wires .-)
And I’m really building this as a kit, I don’t have the knowledge to find other options.
I’m still asking for advice, I’ve found two options
Either should work. The S would be best.