Hi, I'm refactoring a deadbolt lock project I did in 2021 that used a Moteino R6. The R6's I got in 2021 have a voltage regulator (HU6U) and spec said it runs at 16Mhz. I noticed that the current R6's run at 8Mhz and don't have a regulator while the R5's run at 16Mhz and do have a regulator. Sooooo, did the spec change? Regardless, should I get an R5 or R6? My decision to use an R5 vs R6 is based on the nature of the refactoring I'm doing and I'd appreciate input on my thought process. The changes I'm making have to do with getting the lock electronics to power off when the battery gets low. I'm using two 81650s in series (7.4v) to power the lock and the major consumer of power is the stepper motor that throws the deadbolt. The Moteino sleep and uses both watchdog timer and pin change interrupts to wake up. I don't have any problems with detecting low battery, watchdog, and pin change interrupts. Battery voltage detection returns a status of good, low, and critical. My problem is that when it is time stop working because voltage is critical, the Moteino gets wonky, repeatedly restarting, behaving badly (trying to keep this short :-) My plan is to 'cut the power' to the Moteino when battery voltage is critical. I've spent a lot of time looking for /playing with how folks do that and ultimately have decided to use a voltage regulator with an enable pin, which will work as follows: change battery, push start button which enables the voltage regulator, Moteino starts and uses digital pin to keep the voltage regulator enabled even after I've released the start button. When it is time to cut power, the digital pin is flipped, disabling the voltage regulator and shutting down the Moteino and motor driver board. The voltage regulator I'm planning on using is TPS7233QP (3.3v, 250ma). After looking at both R5 and R6 currently available, I figure I could either:
1) get the R6 and connect regulator's Vout too Moteino Vin/3.3....running the risk of code no longer working at 8Mhz.
2) get the R5 and connect regulator's Vout to Moteino 3.3v pin
3) same as #2 but remove the HU6U that comes with the R5, connecting Vin to 3.3v on the Moteino (as is done on the R6)
I'm inclined to go with #3. Anyone see an issue with this?
Somewhat related, it would be nice if the Moteinos' used voltage regulators that could be disabled by code. I've not found a simple way to cut power without increasing sleeping current draw. I'd be happy to pay for that too :-). Apologies in advance if there is a way to do this with the existing designs...if so, please advise!
Many thanks....jimf
Hi jimf,
I'm quite confused by the opening statements.
Where do you see R5 available?
There is a Moteino 8Mhz running at ... 8mhz, but all other AVR Moteinos run at 16mhz.
Felix, menu: shop-->all moteinos--> top of the list, product ID99 image has R5. See attached image.....jim
That first photo has R5 indeed, it's more just illustrative rather than a spec photo that should be analyzed for the parts on it. The rest of the photos have R6.
I added R6 to the title so it's unmistakable.
The MCU is powered from the existing onboard regulator. If you want to use another regulator you will have to remove the existing one. Sounds like your described use might work but how you wire that exactly will be up to you. But it will be a single use it sounds like, and manual restart (you really cut your own power and then reactivate it later (via enable pin)).