Re: [time-nuts] BME280 board.
I have a bunch of these chips, and log everything I can think of. I use the BME280 connected to an Arduino ESP8266 (that has WiFi) The setup itself has no clock. It wakes from sleep, takes a temp, connects to Wifi, sends a JSON string to a server, then sleeps. The server logs the time. Myron Reiss Steel Detailer -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Dan Kemppainen Sent: Wednesday, October 09, 2019 2:18 PM To: time-nuts@lists.febo.com Subject: [time-nuts] BME280 board. Hi All, So it appears several of you have played with the BME280 chip. (Posts below...) A while back I started a project with the BME280 that I didn't around to finishing. Basically, A BME280, PIC24, and Serial to USB cable. The idea WAS to build a temp/pressure/humidity logger for time nuts use. There's an on board 32Khz crystal, and a few pins intended for PPS input or similar. The idea was to use a PPS (Or the RTC, or what ever) to trigger a sample (or every 5 or 10, or any number of PPS's (or seconds)), and send it up the serial port for logging. Anyway, I did layout a board and populated three of them, but ran short of time to get much done with the code. It's been shelved ever since then. If anyone on the list is interested in collaborating on such a project, let me know. I've got an extra board populated for anyone interested in helping on the project. Dan On 10/9/2019 12:00 PM, time-nuts-requ...@lists.febo.com wrote: > -- > From: Adrian Godwin > > Jim mentions the LM34 for sensitivity and LM34 or LM35 for cost compared > with the DS1620. But also look at the BME280 : it has digital measurement > of temperature with 0.01C resolution (50 times better than the DS1620), > costs ?5 on digikey but less mounted on a breakout from ebay, and also > measures pressure. The very similar BME280 also measures humidity. > > -- > From: Didier Juges > > The BME series requires a fair amount of code to convert data from the > sensor into human readable data like degrees. I use the BME280 in some > applications. > > Personally, for just temperature sensing, I found good old fashion > thermistors to be cheaper and more accurate than most silicon sensors while > requiring a single precision resistor and one ADC channel. When used with a > 12 bit ADC, they offer excellent resolution around a relatively small > temperature range, (progressively degrading resolution as you go away from > the optimum temperature) which is ideal for an oven controller. They are > also easy to use in noisy environments. > > Didier KO4BB > > -- > From: Mark Sims > > The BME280 does temperature, humidity, and pressure. They are very nice. > Beware of BME280 boards sold on Ebay, etc. A lot of sellers ship BMP280s. > One way to tell is the BME280 is in a square package and the BMP280 is more > rectangular. > > Also be aware that some BMP/BME280 libraries seem to have some error in their > humidity calculation code and produce incorrect results. > > -- ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] HP105B HP 105B 1 amp fuse blowing
Hi All: A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 hour. The fuse appears to have just melted (not a black mark as the result of a flash, in the case of a high current short.)… just looks like the fuse wire (inside the glass capsule) melted into some little blobs, for about 1/4 the fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... just the normal kind. I think the unit is drawing just a little too much current, as the result of the batteries needing charging (I had the fast charge option on when the fuse blew.) And so, the fuse heated up, and finally melted. Not sure why the batteries were not charging normally... but 20.1 volts is what I measured across the pack, initially, and 23.4 V after about 45 min of charging. I am charging the batters, from a power cube, at 510 ma, and dropping (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in series... that of course is a retrofit. I don't want to put another fuse in, and blow that too, without some reasonable explanation of why the first one failed! Please, any comments, or hints/suggestions... much appreciated. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
Hi I would dump the batteries. If you need backup, run a UPS or some sort of external DC setup. Batteries inside something like the 105 only seem to lead to messy problems down the road. Bob > On Oct 10, 2019, at 2:10 PM, Roy Thistle wrote: > > Hi All: > A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 > hour. > The fuse appears to have just melted (not a black mark as the result of a > flash, in the case of a high current short.)… just looks like the fuse wire > (inside the glass capsule) melted into some little blobs, for about 1/4 the > fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... just > the normal kind. > I think the unit is drawing just a little too much current, as the result of > the batteries needing charging (I had the fast charge option on when the fuse > blew.) And so, the fuse heated up, and finally melted. Not sure why the > batteries were not charging normally... but 20.1 volts is what I measured > across the pack, initially, and 23.4 V after about 45 min of charging. > I am charging the batters, from a power cube, at 510 ma, and dropping (cube > gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in series... > that of course is a retrofit. > I don't want to put another fuse in, and blow that too, without some > reasonable explanation of why the first one failed! > Please, any comments, or hints/suggestions... much appreciated. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP105B HP 105B 1 amp fuse blowing
The fact that 25V supply is dropping to 23.4V shows it is drawing far more current than it is rated. I am assuming this is a regulated power supply. Does the power brick actually shuts down at 500mA or does it let the the voltage drop and try to supply what it can? Maybe one or more Nicad has an internal short? That will cause and over-voltage situation per battery and thus over-current. I've recently seen a brick power supply go into oscillation and produce 3x rated voltage when too much current was drawn. (and blew the circuit) Also, different batteries has different charging rates. As far as 105B document goes, it says 24V 0.5Amp supply but that is for default configuration. Designed charge rate is 390mA (page 3-4) and is current controlled by A5Q3. I would actually measure how much current is drawn there. Since the fuse is already blown, just put an am-meter across the fuse and see --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG On Thursday, October 10, 2019, 4:00:41 PM EDT, Roy Thistle wrote: Hi All: A 105B (quartz oscillator) is blowing the 1A fuse, after it is on about 1 hour. The fuse appears to have just melted (not a black mark as the result of a flash, in the case of a high current short.)… just looks like the fuse wire (inside the glass capsule) melted into some little blobs, for about 1/4 the fuse length, near the middle. It wasn't a fast-blo or slow-blo fuse... just the normal kind. I think the unit is drawing just a little too much current, as the result of the batteries needing charging (I had the fast charge option on when the fuse blew.) And so, the fuse heated up, and finally melted. Not sure why the batteries were not charging normally... but 20.1 volts is what I measured across the pack, initially, and 23.4 V after about 45 min of charging. I am charging the batters, from a power cube, at 510 ma, and dropping (cube gives 25V, 500mA max)… the batteries are 20 C size NiCads, wired in series... that of course is a retrofit. I don't want to put another fuse in, and blow that too, without some reasonable explanation of why the first one failed! Please, any comments, or hints/suggestions... much appreciated. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
