Pingback: Using DS18B20/DHT22 temperature sensor with internal pull-up resistors rather than external ones | Martin's corner on the web
Pingback: Spectrum analysis with RFM12B | Martin's corner on the web
quick question, can I power Funky V3 from 9V battery via 5V pin?
MCP1703 operates in range of 2.7 up to 16V however
I would say no because VBUS is connected to ATMEGA32U4 via pin 2-UVCC and pin 7-VBUS.
Moreover I found a bug in https://harizanov.com/wiki/wiki-home/funky-v3/funky_v3_r3-sch/#main,
Label VCC 3.3V !!! is incorrect it should be 5V or VBUS as per your PCB layout.
Sorry I meant this picture https://harizanov.com/wiki/wiki-home/funky-v3/funky-bottom/#main
“I would say no because VBUS is connected to ATMEGA32U4 via pin 2-UVCC and pin 7-VBUS.”
Exactly.. this is a bit unfortunate, maybe I should have placed a diode just before the voltage regulator. Too late now .
Thanks for pointing out the error on the ISP pins labeling, I just don’t have the original image to edit it; No harm will be done anyway; I’ll have to spare some time and revise it appropriately.
in some of your blogs I found the hint to look into your webshop — and especially for this nice little device here I would be interested to buy one. Is this possible? Your homepage does not show any “shop” link — at least I cannot find one … I think once it was there?!
Thanks a lot in advance!
yes, there used to be a shop where I’d sell the exta units I had..I don’t have free time to support it any more, plus am out of stock on products.
is there anything available on the market that comes close to the Funky? It is exactly what I’m looking for, but I don’t have the means to fabricate the board myself…
Have you tried the Moteino? The form factor isn’t same, but function-wise should be just fine.
I do have few left, just less the radio modules. How many units do you need?
Thanks for great early work on the Funky boards. I have two questions I hope you can answer from your experience:
1.) Since you have both the boost regulator (which works on battery power) and the linear voltage regulator (which works on USB, based on schematic), how is the performance in general? What I’m specifically interested in knowing is – on battery power, is the MCP1703 happy with having 3.3V on its VO pin (from the boost) and nothing on it’s input? Or do we see some reverse current flow back through it and turn it on? Same thing for the boost – when powered by USB, is the boost regulator still switched off with 3.3V on its output (from the linear reg) or is it reverse powered?
2.) What’s the function of the MOSFET on pin D4? It looks like it turns the radio on/off when needed, but not sure why D4 is also connected to RESET.
Regarding 1) True, I have a series of posts on this issue, see http://harizanov.com/2013/03/high-sleep-current-issue-with-funky-v2-sorted-out/ and http://harizanov.com/2013/08/every-%CE%BCa-counts/ for example. Bottomline is that I ended up using the Torex XC6206 which works well.
2) With the default state of RFM12B OFF the pins on an unpowered module look like a series resistance + ESD diode drop to ground . This loads down the SPI bus lines, giving the FLASH programmer a difficult time enforcing a clean waveform. Therefore D4 ensures the module is force powered during reflash with ISP programmer
Comments are closed.