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 "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 "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 "@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
donblair "Update -- based on some tinkering, and some great feedback from folks on the plots-waterquality google group: The power issues no longer seem myst..." | Read more » over 8 years ago