@4994james or just use internal vcc measurement as described on the same page. That saves you the voltage divider.
I wrote a convenient library to measure vcc internally : https://github.com/Yveaux/Arduino_Vcc
You can put 100uf on each even 200uf would not be able to handle only one tx, so..
but you need them at least for coin cells.
you would need more capa to handle tx..but the more capa the more time they take for recharging, and the recharging if big, increase internal res of the coin cell and that's not so good too; to prevent this that would need a current resistor limiter..etc a whole balance!
On mine for instance, I have 100uF for coincell, 100uF for PIR and 86uf on radio. Fresh varta coincell 3.02V, after multiple presentation tx 2.85V if I remember, not so bad. but that's an homemade pcb.
Another notes, it's better to use ceramic capacitor (because of leakage, if you want to optimize), and better smd, but that's not your case I think.
@doctor64 said:
PIR sensors
Not anyone, a sensor that generates a signal when I come close to the car, I rather it not be IR since, AFAIK, they need to be in specific positions to work, unlike NFC or Bluetooth that cover areas around the sensor.
Basically I'm trying to create a smart switch that goes on or of based on whether I'm close (in the range of 10-20 feet) to it or not.
@Yveaux said in Battery Powered Sensors:
.... All was ok, so what did you change (and why)
A the very beginning, hesitating with the procedure, I've probably burnt the Minicore bootloader in the programming ProMini without noticing it... That's the only explanation I see.
Hi @tbowmo, do you mind to explain a bit about the design? I'm interested with your design.
I will use these steps for removing voltage regulator, http://goo.gl/CsZaNg
So the design will be battery > external step up regulator (http://goo.gl/PFt99R - to stabilize 3.3v) > vcc pin ?
with these then I can use my first post design?
Thanks
@NeverDie Perhaps but the design is a bit too simple and unoriginal. I'd have to clean up the files a bit and I haven't touched Eagle since I made this board several years ago.
Finally solved a lot of problems and checked a lot of mistakes. But now the first version of this device works almost properly :trollface:
I will make a small report in the description asap
Qu3Uk,
I did get a chance to test with a Fitbit recently. It technically worked, but not all that well. The thing is, the Fitbit only advertises every 2 seconds so latency is a bit high. But worse, its apps really want to be connected to it often to sync; and whenever it's connected, it stops advertising and the detector then can't pick it up.
TommySharp,
At this point I don't plan to modify the board much but having it read environmental sensors would be a cool feature!
For that, would be nice to make little beacons that read sensors and advertise/broadcast the readings every few seconds. Then they could be very low-power, run on coin-cells for months, and could be placed anywhere instead of needing it to be hooked up to USB power like the main board is. Like these: https://sen.se/peanuts/ I'm curious if it could read them.
As for enclosures, I know. I would love to have some nice ones but at this point I'm making too many boards to 3D print enclosures, but too few to afford injection-molding tooling to make a custom case.
