- Welcome to LowPowerLab Forum.
Recent posts
#11
CurrentRanger / Re: CurrentRangerApp
Last post by vitormhenrique - May 18, 2026, 03:16:24 PMJust a quick update, the mac app is now signed, so installation should be straightforward!
#12
CurrentRanger / Re: CurrentRanger w/ isolation...
Last post by Felix - April 20, 2026, 09:16:34 AMjamie,
Which serial output are you referring to?
There is USB serial output as explained here. There is also the "BT serial header" which will only output if it detects an HC06 bluetooth module but you can recompile to force output I guess.
For isolating the input you could just use a floating power supply (ex battery) to power your PSU.
With USB you could simply use a USB isolator.
So not sure if it's still worth the effort to build an isolator.
Which serial output are you referring to?
There is USB serial output as explained here. There is also the "BT serial header" which will only output if it detects an HC06 bluetooth module but you can recompile to force output I guess.
For isolating the input you could just use a floating power supply (ex battery) to power your PSU.
With USB you could simply use a USB isolator.
So not sure if it's still worth the effort to build an isolator.
#13
ATXRaspi / Re: Voltage drop across ATX bo...
Last post by Felix - April 16, 2026, 01:45:09 PMSomehow I did not see this post until now. It's important to keep all connections very short and with very good quality wiring, thicker wire to reduce any drops across wires.
A 4.8v should still power the Pi without much issue, unless there are more significant drops during heavier load, which are not apparent or easy to spot with a multimeter.
Which ATXRaspi revision was this?
A 4.8v should still power the Pi without much issue, unless there are more significant drops during heavier load, which are not apparent or easy to spot with a multimeter.
Which ATXRaspi revision was this?
#14
Low Power Techniques / Re: Wireless low power battery...
Last post by Felix - April 16, 2026, 01:43:28 PMMaybe it's doable with a ESP+Zigbee, if you put in the leg work to wire up everything.
But I will say anything in the few $ range will require a bunch of effort on your part.
As far as battery life, it will need to be carefully coded to sleep your nodes to an absolute minimum. But keep in mind anything ESP/wifi will take a hit whenever it wakes and connects to wifi, and this is impactful on small batteries.
I stick to my Moteino creations whenever it comes to low power. I have documented real implementations where Moteino based/derived nodes thrive in the most extreme situations for years and years without intervention, on small batteries such as CR123A.
For perspective, in one instance the client came to me to redevelop a solution that was ESP based, same battery type, but the ESP could not keep up pace and hold a charge for more than a few weeks.
But I will say anything in the few $ range will require a bunch of effort on your part.
As far as battery life, it will need to be carefully coded to sleep your nodes to an absolute minimum. But keep in mind anything ESP/wifi will take a hit whenever it wakes and connects to wifi, and this is impactful on small batteries.
I stick to my Moteino creations whenever it comes to low power. I have documented real implementations where Moteino based/derived nodes thrive in the most extreme situations for years and years without intervention, on small batteries such as CR123A.
For perspective, in one instance the client came to me to redevelop a solution that was ESP based, same battery type, but the ESP could not keep up pace and hold a charge for more than a few weeks.
#15
CurrentRanger / Re: CurrentRanger w/ isolation...
Last post by jamie - April 16, 2026, 01:36:25 PMThanks, Felix.
I'm trying to design an isolater so I can use the CR with my Saleae MSO while also measuring voltage via another channel. This scope only has single-ended inputs so the two ideas I had was a) trying to read and decode the serial output from CR using the Saleae's LA channels or b) figure out a way to eliminate the ground loop on the analog inputs. I'm already using all of the LA channels in my test fixture and I'd probably have to use a MCU to issue an "Ok" command anyhow. So Option B seems like the simplest option. I'm aware that it'll limit me to 50 mA, but that's fine for my particular application. (TI also makes the AMC0300R-Q1 with a 250 mA input range).
I'm trying to design an isolater so I can use the CR with my Saleae MSO while also measuring voltage via another channel. This scope only has single-ended inputs so the two ideas I had was a) trying to read and decode the serial output from CR using the Saleae's LA channels or b) figure out a way to eliminate the ground loop on the analog inputs. I'm already using all of the LA channels in my test fixture and I'd probably have to use a MCU to issue an "Ok" command anyhow. So Option B seems like the simplest option. I'm aware that it'll limit me to 50 mA, but that's fine for my particular application. (TI also makes the AMC0300R-Q1 with a 250 mA input range).
#16
Pi Gateway / Re: Fresh Install of Pi Gatewa...
Last post by Felix - April 16, 2026, 01:26:24 PMI do but I get pulled into more meaty projects and I have to prioritize.
Whenever I have some time I try to be consistent with the important LowPowerLab products and support and invest where most interest is shown.
Whenever I have some time I try to be consistent with the important LowPowerLab products and support and invest where most interest is shown.
#17
CurrentRanger / Re: CurrentRangerApp
Last post by Felix - April 16, 2026, 01:24:53 PMNice work, thank you for sharing!
#18
CurrentRanger / Re: CurrentRanger w/ isolation...
Last post by Felix - April 16, 2026, 01:18:02 PMNot sure how you're trying to use the CR with that amp but the input range of that part is +/- 50mV.
The CR can output up to 3.3V depending on the current seen at the input.
The CR output is not really designed to drive any load whatsoever, however since the input impedance of your isolation amp is high it should be OK. However I can't speak to the noise figures since I don't know enough and even then an experiment is needed to verify the theory.
You will have to worry about powering your amp from both isolated sides.
Since this is experimental I hope you know what you are doing and wish you good luck :-)
The CR can output up to 3.3V depending on the current seen at the input.
The CR output is not really designed to drive any load whatsoever, however since the input impedance of your isolation amp is high it should be OK. However I can't speak to the noise figures since I don't know enough and even then an experiment is needed to verify the theory.
You will have to worry about powering your amp from both isolated sides.
Since this is experimental I hope you know what you are doing and wish you good luck :-)
#19
CurrentRanger / CurrentRanger w/ isolation amp...
Last post by jamie - April 16, 2026, 01:19:44 AMI'm planning to feed the CurrentRanger analog output into an isolation amplifier (AMC0302R-Q1), which has a ~6.3 k ohm dynamic input impedance due to a switched-cap front end.
Can the CurrentRanger analog output drive a load in that range without introducing significant measurement error or other issues? Thanks.
Can the CurrentRanger analog output drive a load in that range without introducing significant measurement error or other issues? Thanks.
#20
General topics / rtl_433 now supports RFM69 / M...
Last post by icockett - April 13, 2026, 03:35:33 AMHi all,
Just FYI. The popular https://github.com/merbanan/rtl_433 project now supports Moteino RFM69 boards using a standard SDR setup. The repo contains a simple example that works with the Moteino sample Node project, but is easy to adapt for other types of custom message.
I've used this for several years to combine Moteino based sensors with other 433MHz kit using a single RPI with an SDR dongle. Works very well. I finally got round to pushing the code last year and it's just appeared in the latest version.
rtl_433 now has over 300 supported types of devices such as off-the-shelf temperature and weather sensors and energy monitors.
Enjoy.
Ian
Just FYI. The popular https://github.com/merbanan/rtl_433 project now supports Moteino RFM69 boards using a standard SDR setup. The repo contains a simple example that works with the Moteino sample Node project, but is easy to adapt for other types of custom message.
I've used this for several years to combine Moteino based sensors with other 433MHz kit using a single RPI with an SDR dongle. Works very well. I finally got round to pushing the code last year and it's just appeared in the latest version.
rtl_433 now has over 300 supported types of devices such as off-the-shelf temperature and weather sensors and energy monitors.
Enjoy.
Ian