Comments

Author Comment Last activity Moderation
donblair "Great question re: whether powering the Feather on the 3V line really does work well ... I don't really know. But: looking at a schematic for one ..." | Read more » over 6 years ago
donblair "Thanks Chris -- this is incredibly useful. So important for folks to have a sense of the trade-offs and considerations when choosing solutions in ..." | Read more » over 6 years ago
donblair "Hi @gretchengehrke! Sorry for the much-delayed reply :) and thanks for the comment. I, too, liked this approach -- basically, using the differenc..." | Read more » over 6 years ago
donblair "Hallo! If the hardware is Riffle version 0.1.8, the relevant schematic is here -- and, so far as I can tell, VBAT should simply be the battery inp..." | Read more » over 6 years ago
donblair "Hi Rebeccah! Fantastic stuff here. Lots to digest, and I have several thoughts -- but first, quickly: the frequency output of the Coqui requires..." | Read more » almost 8 years ago
donblair "This is gorgeous! So cool! (Were you able to use the washer without bumping into any components on the board? Been worried bout whether using th..." | Read more » about 8 years ago
donblair "Yay, data!! Neat observation about the battery voltage and the temperature. Makes me want to compare the rate of battery voltage drop to the temp..." | Read more » about 8 years ago
donblair "Bravo!! This is amazing. This makes me wonder what accounts for the rest of that quiescent current draw ... maybe the majority of it is due to th..." | Read more » about 8 years ago
donblair "This is so fantastic. So neat to see the current spikes with the SD card writes! ANd ... oh, my, what a terribly high sleeping current ... I sho..." | Read more » about 8 years ago
donblair "Chris, This is such a beautiful project! The lapse rate calculation is so fun to see. Quick reactions: That power switch goof is annoying. I w..." | Read more » about 8 years ago
donblair "Wow, great work. Sorry that there's so much trouble dealing with drivers for this USB-Serial chip! Re: the capacitive sensor circuit ... do you s..." | Read more » about 8 years ago
donblair "@ggallant -- Wow, this is fantastic detective work. Does it seem that you were able to resolve the uC resetting issue with the extra cap parallel ..." | Read more » about 8 years ago
donblair "Hi Chris! This is fantastic research. So many interesting questions coming up already via your testing. Thank you. Riffleman! These rechargeabl..." | Read more » about 8 years ago
donblair "@cfastie: Power estimates are next on my list :) Looks like I should be able to switch off power to the camera completely using the microcontrolle..." | Read more » over 8 years ago
donblair "-- a CR1220 coin cell. " | Read more » over 8 years ago
donblair "Wow, amazing note. Thanks so much for putting all this so nicely together, @mathew!!! Still digging in, but quick thoughts: The 6-32 screws wit..." | Read more » over 8 years ago
donblair "@pdhixenbaugh -- Good point! I do think the self-discharge rate on these various battery chemistries does differ, but I don't know by how much. Le..." | Read more » over 8 years ago
donblair "Hey All! Okay, after a bunch of discussion last night, it seems that the above P-Mos circuit will work, but the battery leakage is significant. A..." | Read more » over 8 years ago
donblair "Further elaboration on this circuit solution: The idea (nicely described in the blog post) is to use a P-channel Mosfet arranged so that when USB ..." | Read more » over 8 years ago
donblair "(Also note: I've added an extra capacitor to the circuit, so that I'll have a 10uF close to the lithium charger, and on both sides of the LDO) " | Read more » over 8 years ago
donblair "Okay, here's my interpretation of the more advanced circuit: Full schematic: Close-up on the relevant power circuitry: Load balancing is ac..." | Read more » over 8 years ago
donblair "For further reference (both of the below pics are from the above-referenced blog post, the minimal schematic for the charger chip (which I'd been u..." | Read more » over 8 years ago
donblair "Update: What I'd observed was that the previous version of the riffle -- 0.96 -- seemed to allow for USB programming even when a battery wasn't pl..." | Read more » over 8 years ago
donblair "Update: I've attempted to incorporate both the fix to the switch, and the new diode-based power management strategy, in the Riffle 0.1.4 schematic..." | Read more » over 8 years ago