I see the bandwidth for this product is given as 300KHz, I haven't done any real life tests, but would you say that is enough to measure the current of an ESP32 type device?
@@voltlog Now based on Andreas's review I would say its sufficient. In any case you should be able to capture very fast current transients for any low power electronic product (up to the 3.3A range).
Congratulations on a very nice product design! Have you done any tests to see if the bandwidth (300KHz) is sufficient to capture the current usage of low power SOCs like an ESP32 or similar?
Thanks! I'm not a fan of ESP products nor have I used them much at all, so I don't know how they behave. The bandwidth is sufficient to capture very fine current variations in RFM69 transceivers, see the guide for measurements/scope captures.
Some videos on how best to use this or how to commonly use it would be nice. I'm not sure about the serial output but that seems like a great feature if you want to watch how the current changes over time (transmitting, etc)
For the next revision i would narrow down the oled header holes to 0.8-0.85mm such that the shield plugs in directly without any socket, it will look cooler.
Love the product and the specs. Just one suggestion - you have a lot of options at checkout time for OLED adder and what not. Why not make the LIPO battery an option? Cost me a couple days - I have a bunch of LIPOs around the lab, but they are all three pin and wouldn't work.
It's a good expansion on µCurrent, great work. My main worry is, that all these bells and whistles would add noise or other interference to sensitive measurements unnecessarily. Have you made any characterizations regarding that and are you going top release any sort of data-sheet like specifications for the unit?
It's all a tradeoff. If you want high bandwidth and low noise output, then use the CurrentRanger the same way as the µCurrent, no auto-ranging or OLED. If you can trade some bandwidth for even lower noise, then use the LPF, reduces noise dramatically and gives you silky smooth traces on a scope. If all you need is a DMM, then you can enable everything, the readings on a RMS DMM are unaffected even with continuous ADC sampling.
I am not sure if this is the place to ask. I just ordered a CurrentRanger. I need to look at sleep currents at a couple uA, uController wake currents at a couple mA, LED currents of a dozen mA in tens of ms pulses, and radio transmit current draws of 80 mA in tens of uS pulses of current draw. As these overlay on one another and the CurrentRanger autoranges, how can I know if what I have on the oscilloscope is show a mV per nA or uA or mA? Do I need to probe the LED outputs for the three ranges at the same time that I probe the real time voltage output? Nice creation BTW, I am looking forward to putting it to use.
Please DO NOT probe the LEDs while probing the output, this is a good way to damage the CR since the grounds of the output/LEDs/USB/input are different so doing that will create ground loops. I would suggest just placing the CR in manual mA mode, then it will give you a good clear output and you'll know how it looks like when it wakes up. Then for the sleep part go in uA mode - the CR should not choke your DUT in uA mode even if it wakes up, assuming it only uses a few mA in wake mode. Be sure to read the warnings in the guide before you hook it up to multiple external devices, this is important since there is no built in isolation in the device - this is a 2 edged sword - gives you maximum raw output bandwidth but you have to understand how to properly use the device. Please ask future Qs in the lowpowerlab.com/forum, thanks.
Thanks ytfp! RE pricing - it's a multifold reason, first the board themselves are pretty time consuming to SMD-assemble, program, test, and the BOM has a lot of different parts some of which are quite pricey, so overall it's a complex thing that takes me a significant amount of time per unit to produce. I prefer to sell fewer units to people that can appreciate the value they get for a price which I regard as fair, especially compared to a uCurrent. M0+ is sufficient for what I need it to do, and its plenty fast. If M4 becomes a better candidate for I will consider using it in the future :)
Hello Felix, ich have just seen the great review of Andreas, [with the swiss acent ;-)], and immediately ordered this smart thingy at Welectron. What I don't yet know and might be a suggestion: Upon auto.switching, is there a signal somewhere available, which I could visualize on my scope? I mean: whenever the CurrentRanger switches to a different range, I'd like to see this in my scope on a second channel: just 5V, or, even better, a dedicated level for each of the three ranges or a short/medium/long pulse of LOW to HIGH or vice versus to identify the active range on the scope. Hope this was understandable. As to the rest: excellent job!
Hello Overtan! Thanks for your question, this would be a great question for the forum - lowpowerlab.com/forum/currentranger/ Although it appears to be, I did not say it's open source :-). But to answer quick - there is no dedicated signal for this. But you can reprogram the unit yourself with the code and use the exposed GPIO header (bottom right) to make your own signal for that. So you could use 1 GPIO to output short pulses *after* each ranging. However this needs to be carefully considered to ensure the CR won't be damaged by having an external device (EARTH GROUND) connected to 2 different potentials in the circuit (output- and MCU GND). Maybe I can make this a standard feature that can be enabled through the OLED/MENU in the future.
@@FelixRusu Yes, the best thing of all: Open Source, love it (I write software for a living, linux only). Yes, a good proposal. But it just came as well to my mind, that the range-LEDs already output this information. I'll have a look at it when it arrives. Thanks! BTW: "Overtan" sounds awesome, I like it. But it is "Obertan", a word which doesn't actually exist in German, a "portmanteau". "Obertan" is so to say "~Untertan". ;-)
@@obertan_1 Sorry I mangled your name! Be careful if you want to tap into the LEDs. They will not have the same GND as the scope output, and you want to avoid running current loops through the MCU. Especially when it is used in BIAS mode, now the output- is 1.65V above the LEDs GND, so you're overloading the circuit.
@@obertan_1 An afterthought - you can redirect to USB logging the exponential notation logging used for the BT serial header. Then you don't need to watch another signal since the output already tells you what range you are in, ex: 123E-3 (mA range).
Oh that's way cooler than the uCurrent. Is it open hardware? I'd like to make my version with some changes, such as a BNC port and the footprints for the components i've already in stock
Thanks, I will release the schematic and code. I don't think BNC will help since you need some attenuation or your tracing could be very noisy. If you really want BNC there are dual banana jack to BNC terminals available for $5ish on ebay.
@@FelixRusu i'm not planning to use bnc for better noise immunity, just as a more convenient connector to attach the scope. There should be no significant difference between direct bnc and banana to bnc, right?
valerio ew I was saying that for BNC use you will need a very good coax to limit noise. I would just get a banana/BNC adapter. In fact I got one just for this purpose and I was not happy about the noise. In the many months of development I thought of all these connectivity options including BNC. I decided not to bother with BNC because of several reasons. The simple 2 pin header for scope probe cannot be beat in terms of noise.
In theory, there are a raft of reasons it's much better to use a well-matched probe with a short ground lead at the board, like felix does in this demo. It's definitely not the same as attaching a coax, directly to a coax jack you integrate, or via bnc to banana. Among other things, the coax option would represent two different impedance discontinuities, which could lead to unexpected noise: the (whatever the currentranger impedance is)>50ohm, and the second 50ohm>scope (Assume 1mohm). Of course, this particular piece isn't relevant if you're measuring with 50ohm coupling at the scope, but you probably aren't, and also shouldn't be. Long story short, you can only assume "1MOhm||13pf" if you're using the probe tip itself, and that's probably what you want to do. In practice, I wouldn't put money on a huge difference. Although if Felix says he ran into issues, I totally believe that for the reasons above. The ideal scenario is probably a BNC jack and you use a scope probe to BNC adapter, but this is less convenient and only approximately as good as just using the ground spring.
I personally would love to have a current meter that is using high dynamic log-opamp, and basically outputs mV/dBmA or something close to that (for example 1nA => 100mV, 10nA => 200mV, 100nA => 300mV, 1uA => 400mV, 10uA => 500mV, 100uA => 600mV, 1mA => 700mV, 10mA => 800mV, 100mA => 900mV, 1A => 1000mV, 3.3A => 1519mV; the exact values could be determined to make the best use of available input and output dynamic range). Then I don't need any autoranging in the meter, I can do continues logging using a meters, data logger or osciloscope. Then in software (or osciloscope using math functions) I can invert the log, by using exp or 10^x function, and get back original current over full range, with constant relative accuracy over whole range.
Everyone would, but to make something like that you need an exceptionally low noise design, exceptionally high resolution and fast ADCs, and a very fast processor - something in a very different price range. An higher end oscilloscope has that kind of architecture, but not specifically designed to do current measurements but voltage measurements. Perhaps a nice SMU like the $6K Keithley 2450 could also do that but I believe that also ranges.
@@FelixRusu I don't think it is that hard. Lets say 20bit ADC, at about 100ksps, these are readily available. with 20bits, and 0-1V scale, that translates to 0.004mV per step, which is also available using even medium quality voltage reference. That is not that low, to be hard to noise-proof. The 0.004mV in log scale, would be equivalent (in my example of 100mV per decade), to less than 0.01% relative accuracy (0.004% to be precise). Way more than actually needed in majority of power measurements. The absolute calibration shouldn't be hard either I think, using multi point methods. The cheap DC log-amp like MAX4206 might not be the best, but it pretty good, good bandwidth and price, but it is only 5 decades, with a bit extra non-linearity at the edges of ranges, but is an option, a better one would be to have close 8 decades, for example TI LOG114, low noise, high bandwidth, 4.2$ per IC. I just hypothesizing here of course, but I am pretty sure it doesn't need to be hard, big or expensive.
@@movax20h If parts were the only thing you need to factor into finished product economics we'd live in a very different world. Anyway sounds like a great product idea, looking forward to see it implemented in practice ;-)
That is big upgrade to uCurrent. I like LPF, autorange, all those different input and output options, OLED (I would use it most of the time) and the fact that in can go up to 3.3A. As far as logging over usb: you could have usb insulation, you have several options, if you don't want to use BT How stable is it, what the precision?
If it's complete galvanic isolation then it could work, but any extensions to the board can act as antennas that pick up noise. RE stable/precision - I haven't tried it so I don't know the answer. I know the BT works pretty well - but these will be ADC readings, not the highest accuracy that you could get via a DMM.
We are actually planning to buy it. What is the max range of current it can take? as we are using LORA and its peak current is 140mA. We want to study sleep currents and battery life calculation with help of this device.
@@FelixRusu we have purchased the ranger. Its nice product. Thank you. I wanted to know what is sampling speed in milliseconds for serial logging? FAST ,AVG & SLOW. We wanted that info for serial plotting.
@@designeme1809 This will depend on several factors, so it's not a fixed speed. It can be 1-2ksps, try the CurrentViewer, it shows the sampling rate in the GUI. github.com/MGX3D/CurrentViewer
@@FelixRusu thank you. We found the GUI. Our main application requires Battery Life calculation. Do you which software will be best to find that out using our current ranger data? Found some information on Grafana. But We are not expertise in that area.
That is up to you, we just provide a generic serial output that you can plug into the program of your choice. On the CR product guide there are some suggested 3rd party programs which you can try out: lowpowerlab.com/guide/currentranger/bluetooth-data-logging/
Looking for an instruction on the firmware. I use Arduino regularly but it doesn't recognize the Current Ranger. Really all I want to do is disable auto power down.
If you don't have the latest firmware there is a bug that will prevent AUTO-OFF to function properly (unit will still turn OFF after several hours). So first I would update the firmware, follow the guide here for that: lowpowerlab.com/guide/currentranger/programming-firmware-updates/ Secondly, there is a serial menu that allows you to disable AUTO-OFF functionality, explained here: lowpowerlab.com/guide/currentranger/auto-power-off-function/
bought! btw Felix's products are a bit hard to get in Europe and shipping from The States take a time. But you can get the CurrentRanger from www.welectron.com/LowPowerLab-CurrentRanger-Strom-Messverstaerker-mit-Display in Europe. Would be nice to see more products from lowpowerlab.com in that shop or an other Europe reseller.
Thanks, I know you have to pass current through it and it that current that is being measured. But what voltage w.r.t. ground can be applied at the input? That is can it be inserted in the high side of a 12v battery to determine the current supplied to a 12 v load?
Yes, you can. But be sure to float the Current Ranger, it is not connected to ANY ground whatsoever or you can damage it. That's the key. You just pass the 12v high through it, that's it, nothing else.
This product has poor design and easily gets damaged. The usual failure modes like earth looping, reverse current, reverse polarity, over voltage and over current protection which is normal in almost all professional instruments, is not implemented in design. Using a 1 to 5 ohms resistor in series to the supply and measuring the voltage across the resistor gives more accurate reading in Microamps or nano amps.
It's very easy to declare something "poor design" without explaining the problem and offering a solution. I put together an extensive and detailed guide to help users understand the device, its proper usage, its limitations. The CurrentRanger is conceptually a relatively simple device that does a few things well, when properly used. It cannot be compared to high end multi thousand dollar instruments. Actually several users have compared it to high end devices, and found it to be accurate and enjoy using it, see the forums and testimonials. Protection devices were not included intentionally to avoid current leakage and throwing off readings. I did include SMD pads for over voltage protection at the inputs, if you would like to trade off for some accuracy you can mount diodes there. Earth looping can be easily avoided if you use a USB isolator and follow some common sense. Or the cost would be higher to implement all these protections which are not really needed if you know what you are doing. But from your statements I am not confident you truly understand how to use the device. "Using a 1-5ohms in series" with the DUT is a very limited and impractical method of measuring current because of the burden voltage drops it introduces, not to mention noise and other issues. If that worked well I would never have bothered to make this device.
@@FelixRusu I don't deny the effort on the design, however there's lots of should and shouldn't to use your device. The burden voltage is a misleading false problem you are suggesting, the user of your device is about to measure only a few micro amps or nano amps, otherwise they would use a multimeter. With one ohm series resistor the burden voltage is negligible a few microvolts only. With the noise issue even your design atracts noise and you already emphasizing in this video and suggesting to use Bluetooth isolation. For a non commercial grade gadget like this with max prototyping cost of $20, your device is highly overpriced. And the price suggests it is a well designed instrument which has looked at different failure modes and mitigated them.
@@FelixRusu I consider my CurrentRanger an absolute bargain. With all the options plus the sickening 27% VAT imposed by EU, I ended up paying just over $200. This compact marvel will readily solve my childhood dream project challenge, the ultimate crystal radio instrumentation , a "final frontier" in Low Power. I am very happy and grateful for Felix's fabulously improved product, and I have no problem paying for it. Actually, I would have been willing to pay even more. It is all in the eye of the beholder. Call it a toy if you must, but "He who dies with the most/best toys wins". And I will have a blast playing with it.
Persze magyaroknak minden dolcsi-ár "drága". Akkor miért nem csinálsz egy jobbat, sokkal olcsóbban? Gyorsan meggazdagodhatsz! Vagy ez nem is olyan egyszerű, csak jártatjuk a szánkat? (GoogleTranslate from Hungarian if you don't get it)
@@DAVID999383 Thank you for your feedback, I'm happy to hear from yet another content user who can understand and see the value of CurrentRanger. I priced it to what I considered was a fair price given the complexity and time spent to develop and produce it, the parts are not cheap, the enclosures take almost 2 hours to print for 1 CR. The CR is NOT "made in china" but some people will never be happy unless everything costs $20 or cheaper.
This is a great product. Especially the auto ranging feature is very handy for any deep-sleep measurements.
I see the bandwidth for this product is given as 300KHz, I haven't done any real life tests, but would you say that is enough to measure the current of an ESP32 type device?
Thanks Andreas!
@@voltlog I am pretty sure even at 10khz you will get a very good idea of what the ESP32 is doing.
@@voltlog Now based on Andreas's review I would say its sufficient. In any case you should be able to capture very fast current transients for any low power electronic product (up to the 3.3A range).
@@FelixRusu Thanks! I saw Andreas's review, it painted the picture clearly.
Mine arrived this week, amazing tool and just what I needed for a project I am working on. Thanks
Dave caught sleeping on the uCurrent 😁 This is a great upgrade, well done!
Congratulations on a very nice product design! Have you done any tests to see if the bandwidth (300KHz) is sufficient to capture the current usage of low power SOCs like an ESP32 or similar?
Thanks!
I'm not a fan of ESP products nor have I used them much at all, so I don't know how they behave.
The bandwidth is sufficient to capture very fine current variations in RFM69 transceivers, see the guide for measurements/scope captures.
Andreas Spiess mentions you in his videos. I hope to learn as much with your videos as I do with his.
Some videos on how best to use this or how to commonly use it would be nice. I'm not sure about the serial output but that seems like a great feature if you want to watch how the current changes over time (transmitting, etc)
This is really nice. Just ordered one couple days ago.
Awesome! Looks great. Just ordered one and can't wait to try it out.
Just bought one after Andreas Spiess alerted me to it. Arrived today😀🏴
For the next revision i would narrow down the oled header holes to 0.8-0.85mm such that the shield plugs in directly without any socket, it will look cooler.
Wow is is a really impressive product! Very well done.
Thank u sir :)
Oh wow. So much better than uCurrent meter!
Thanks!
Love the product and the specs. Just one suggestion - you have a lot of options at checkout time for OLED adder and what not. Why not make the LIPO battery an option? Cost me a couple days - I have a bunch of LIPOs around the lab, but they are all three pin and wouldn't work.
Thank you for the message, it has to do with regulations around shipping LiPo batteries with USPS.
It's a good expansion on µCurrent, great work.
My main worry is, that all these bells and whistles would add noise or other interference to sensitive measurements unnecessarily.
Have you made any characterizations regarding that and are you going top release any sort of data-sheet like specifications for the unit?
It's all a tradeoff. If you want high bandwidth and low noise output, then use the CurrentRanger the same way as the µCurrent, no auto-ranging or OLED.
If you can trade some bandwidth for even lower noise, then use the LPF, reduces noise dramatically and gives you silky smooth traces on a scope. If all you need is a DMM, then you can enable everything, the readings on a RMS DMM are unaffected even with continuous ADC sampling.
I am not sure if this is the place to ask. I just ordered a CurrentRanger. I need to look at sleep currents at a couple uA, uController wake currents at a couple mA, LED currents of a dozen mA in tens of ms pulses, and radio transmit current draws of 80 mA in tens of uS pulses of current draw. As these overlay on one another and the CurrentRanger autoranges, how can I know if what I have on the oscilloscope is show a mV per nA or uA or mA? Do I need to probe the LED outputs for the three ranges at the same time that I probe the real time voltage output? Nice creation BTW, I am looking forward to putting it to use.
Please DO NOT probe the LEDs while probing the output, this is a good way to damage the CR since the grounds of the output/LEDs/USB/input are different so doing that will create ground loops. I would suggest just placing the CR in manual mA mode, then it will give you a good clear output and you'll know how it looks like when it wakes up. Then for the sleep part go in uA mode - the CR should not choke your DUT in uA mode even if it wakes up, assuming it only uses a few mA in wake mode. Be sure to read the warnings in the guide before you hook it up to multiple external devices, this is important since there is no built in isolation in the device - this is a 2 edged sword - gives you maximum raw output bandwidth but you have to understand how to properly use the device. Please ask future Qs in the lowpowerlab.com/forum, thanks.
Sick awesome Felix! Just dont' see why it has to be so pricey. Why an m0 and not an m4? I'll support anyway but just curious!
Thanks ytfp!
RE pricing - it's a multifold reason, first the board themselves are pretty time consuming to SMD-assemble, program, test, and the BOM has a lot of different parts some of which are quite pricey, so overall it's a complex thing that takes me a significant amount of time per unit to produce. I prefer to sell fewer units to people that can appreciate the value they get for a price which I regard as fair, especially compared to a uCurrent.
M0+ is sufficient for what I need it to do, and its plenty fast. If M4 becomes a better candidate for I will consider using it in the future :)
Felix Rusu Thanks, looks like I clicked order too late, have to wait for the next batch. Yea look into the m4!
Hello Felix,
ich have just seen the great review of Andreas, [with the swiss acent ;-)], and immediately ordered this smart thingy at Welectron. What I don't yet know and might be a suggestion: Upon auto.switching, is there a signal somewhere available, which I could visualize on my scope? I mean: whenever the CurrentRanger switches to a different range, I'd like to see this in my scope on a second channel: just 5V, or, even better, a dedicated level for each of the three ranges or a short/medium/long pulse of LOW to HIGH or vice versus to identify the active range on the scope. Hope this was understandable.
As to the rest: excellent job!
Hello Overtan!
Thanks for your question, this would be a great question for the forum - lowpowerlab.com/forum/currentranger/
Although it appears to be, I did not say it's open source :-). But to answer quick - there is no dedicated signal for this. But you can reprogram the unit yourself with the code and use the exposed GPIO header (bottom right) to make your own signal for that. So you could use 1 GPIO to output short pulses *after* each ranging. However this needs to be carefully considered to ensure the CR won't be damaged by having an external device (EARTH GROUND) connected to 2 different potentials in the circuit (output- and MCU GND). Maybe I can make this a standard feature that can be enabled through the OLED/MENU in the future.
@@FelixRusu Yes, the best thing of all: Open Source, love it (I write software for a living, linux only). Yes, a good proposal. But it just came as well to my mind, that the range-LEDs already output this information. I'll have a look at it when it arrives. Thanks!
BTW: "Overtan" sounds awesome, I like it. But it is "Obertan", a word which doesn't actually exist in German, a "portmanteau". "Obertan" is so to say "~Untertan". ;-)
@@obertan_1 Sorry I mangled your name!
Be careful if you want to tap into the LEDs. They will not have the same GND as the scope output, and you want to avoid running current loops through the MCU. Especially when it is used in BIAS mode, now the output- is 1.65V above the LEDs GND, so you're overloading the circuit.
@@obertan_1 An afterthought - you can redirect to USB logging the exponential notation logging used for the BT serial header. Then you don't need to watch another signal since the output already tells you what range you are in, ex: 123E-3 (mA range).
Oh man, so excited to get me one!
Oh that's way cooler than the uCurrent. Is it open hardware? I'd like to make my version with some changes, such as a BNC port and the footprints for the components i've already in stock
Thanks, I will release the schematic and code. I don't think BNC will help since you need some attenuation or your tracing could be very noisy. If you really want BNC there are dual banana jack to BNC terminals available for $5ish on ebay.
@@FelixRusu i'm not planning to use bnc for better noise immunity, just as a more convenient connector to attach the scope. There should be no significant difference between direct bnc and banana to bnc, right?
valerio
ew I was saying that for BNC use you will need a very good coax to limit noise. I would just get a banana/BNC adapter. In fact I got one just for this purpose and I was not happy about the noise.
In the many months of development I thought of all these connectivity options including BNC. I decided not to bother with BNC because of several reasons. The simple 2 pin header for scope probe cannot be beat in terms of noise.
In theory, there are a raft of reasons it's much better to use a well-matched probe with a short ground lead at the board, like felix does in this demo. It's definitely not the same as attaching a coax, directly to a coax jack you integrate, or via bnc to banana. Among other things, the coax option would represent two different impedance discontinuities, which could lead to unexpected noise: the (whatever the currentranger impedance is)>50ohm, and the second 50ohm>scope (Assume 1mohm). Of course, this particular piece isn't relevant if you're measuring with 50ohm coupling at the scope, but you probably aren't, and also shouldn't be. Long story short, you can only assume "1MOhm||13pf" if you're using the probe tip itself, and that's probably what you want to do.
In practice, I wouldn't put money on a huge difference. Although if Felix says he ran into issues, I totally believe that for the reasons above. The ideal scenario is probably a BNC jack and you use a scope probe to BNC adapter, but this is less convenient and only approximately as good as just using the ground spring.
Did you follow up and release the code and schematics? I couldn’t find them on your page or github but saw Andreas video today and he had them
I personally would love to have a current meter that is using high dynamic log-opamp, and basically outputs mV/dBmA or something close to that (for example 1nA => 100mV, 10nA => 200mV, 100nA => 300mV, 1uA => 400mV, 10uA => 500mV, 100uA => 600mV, 1mA => 700mV, 10mA => 800mV, 100mA => 900mV, 1A => 1000mV, 3.3A => 1519mV; the exact values could be determined to make the best use of available input and output dynamic range). Then I don't need any autoranging in the meter, I can do continues logging using a meters, data logger or osciloscope. Then in software (or osciloscope using math functions) I can invert the log, by using exp or 10^x function, and get back original current over full range, with constant relative accuracy over whole range.
Everyone would, but to make something like that you need an exceptionally low noise design, exceptionally high resolution and fast ADCs, and a very fast processor - something in a very different price range. An higher end oscilloscope has that kind of architecture, but not specifically designed to do current measurements but voltage measurements. Perhaps a nice SMU like the $6K Keithley 2450 could also do that but I believe that also ranges.
@@FelixRusu I don't think it is that hard. Lets say 20bit ADC, at about 100ksps, these are readily available. with 20bits, and 0-1V scale, that translates to 0.004mV per step, which is also available using even medium quality voltage reference. That is not that low, to be hard to noise-proof. The 0.004mV in log scale, would be equivalent (in my example of 100mV per decade), to less than 0.01% relative accuracy (0.004% to be precise). Way more than actually needed in majority of power measurements. The absolute calibration shouldn't be hard either I think, using multi point methods. The cheap DC log-amp like MAX4206 might not be the best, but it pretty good, good bandwidth and price, but it is only 5 decades, with a bit extra non-linearity at the edges of ranges, but is an option, a better one would be to have close 8 decades, for example TI LOG114, low noise, high bandwidth, 4.2$ per IC. I just hypothesizing here of course, but I am pretty sure it doesn't need to be hard, big or expensive.
@@movax20h If parts were the only thing you need to factor into finished product economics we'd live in a very different world. Anyway sounds like a great product idea, looking forward to see it implemented in practice ;-)
@@FelixRusu I wish, I don't know that much about electronics. Maybe one day,.
Nice product, well done.
One more question :). Is there an instruction to set up the HC06 BT logger? It is definitely not straightforward.
Please see: lowpowerlab.com/guide/currentranger/bluetooth-data-logging/
That is big upgrade to uCurrent. I like LPF, autorange, all those different input and output options, OLED (I would use it most of the time) and the fact that in can go up to 3.3A.
As far as logging over usb: you could have usb insulation, you have several options, if you don't want to use BT
How stable is it, what the precision?
If it's complete galvanic isolation then it could work, but any extensions to the board can act as antennas that pick up noise.
RE stable/precision - I haven't tried it so I don't know the answer. I know the BT works pretty well - but these will be ADC readings, not the highest accuracy that you could get via a DMM.
I have no use for this but it sure seems much cooler than the ucurrent one. How does the touch mechanism work?
It uses the touch controller in the SAMD21 M0+.
We are actually planning to buy it. What is the max range of current it can take? as we are using LORA and its peak current is 140mA. We want to study sleep currents and battery life calculation with help of this device.
Hi Design EME - It can measure up to ~3.3A.
@@FelixRusu we have purchased the ranger. Its nice product. Thank you. I wanted to know what is sampling speed in milliseconds for serial logging? FAST ,AVG & SLOW. We wanted that info for serial plotting.
@@designeme1809 This will depend on several factors, so it's not a fixed speed. It can be 1-2ksps, try the CurrentViewer, it shows the sampling rate in the GUI. github.com/MGX3D/CurrentViewer
@@FelixRusu thank you. We found the GUI. Our main application requires Battery Life calculation. Do you which software will be best to find that out using our current ranger data? Found some information on Grafana. But We are not expertise in that area.
That is up to you, we just provide a generic serial output that you can plug into the program of your choice. On the CR product guide there are some suggested 3rd party programs which you can try out: lowpowerlab.com/guide/currentranger/bluetooth-data-logging/
well done !
Awesome device!
is there any distributor in europe?
Yes It can be found at welectron.com in Germany
Looking for an instruction on the firmware. I use Arduino regularly but it doesn't recognize the Current Ranger. Really all I want to do is disable auto power down.
If you don't have the latest firmware there is a bug that will prevent AUTO-OFF to function properly (unit will still turn OFF after several hours). So first I would update the firmware, follow the guide here for that: lowpowerlab.com/guide/currentranger/programming-firmware-updates/
Secondly, there is a serial menu that allows you to disable AUTO-OFF functionality, explained here: lowpowerlab.com/guide/currentranger/auto-power-off-function/
@@FelixRusu Thank you!
Can I use the I2C channel to read the measurement data with a microcontroller?
You could but you'd have to modify the firmware, and I would not recommend that. It would be way slower than serial output.
What is the voltage limition? 0 to ?
bought! btw Felix's products are a bit hard to get in Europe and shipping from The States take a time. But you can get the CurrentRanger from www.welectron.com/LowPowerLab-CurrentRanger-Strom-Messverstaerker-mit-Display in Europe. Would be nice to see more products from lowpowerlab.com in that shop or an other Europe reseller.
What is the maximum input voltage?
You need to read the guide, you cannot apply a voltage to this device, you need to pass a current through it.
lowpowerlab.com/currentranger
Thanks, I know you have to pass current through it and it that current that is being measured. But what voltage w.r.t. ground can be applied at the input? That is can it be inserted in the high side of a 12v battery to determine the current supplied to a 12 v load?
Yes, you can. But be sure to float the Current Ranger, it is not connected to ANY ground whatsoever or you can damage it. That's the key. You just pass the 12v high through it, that's it, nothing else.
@@FelixRusu Thank you. Got it
What mosfet is used by currentranger
Is that open source product?
This product has poor design and easily gets damaged. The usual failure modes like earth looping, reverse current, reverse polarity, over voltage and over current protection which is normal in almost all professional instruments, is not implemented in design. Using a 1 to 5 ohms resistor in series to the supply and measuring the voltage across the resistor gives more accurate reading in Microamps or nano amps.
It's very easy to declare something "poor design" without explaining the problem and offering a solution.
I put together an extensive and detailed guide to help users understand the device, its proper usage, its limitations.
The CurrentRanger is conceptually a relatively simple device that does a few things well, when properly used.
It cannot be compared to high end multi thousand dollar instruments.
Actually several users have compared it to high end devices, and found it to be accurate and enjoy using it, see the forums and testimonials.
Protection devices were not included intentionally to avoid current leakage and throwing off readings.
I did include SMD pads for over voltage protection at the inputs, if you would like to trade off for some accuracy you can mount diodes there.
Earth looping can be easily avoided if you use a USB isolator and follow some common sense.
Or the cost would be higher to implement all these protections which are not really needed if you know what you are doing.
But from your statements I am not confident you truly understand how to use the device.
"Using a 1-5ohms in series" with the DUT is a very limited and impractical method of measuring current because of the burden voltage drops it introduces, not to mention noise and other issues.
If that worked well I would never have bothered to make this device.
@@FelixRusu I don't deny the effort on the design, however there's lots of should and shouldn't to use your device. The burden voltage is a misleading false problem you are suggesting, the user of your device is about to measure only a few micro amps or nano amps, otherwise they would use a multimeter. With one ohm series resistor the burden voltage is negligible a few microvolts only. With the noise issue even your design atracts noise and you already emphasizing in this video and suggesting to use Bluetooth isolation. For a non commercial grade gadget like this with max prototyping cost of $20, your device is highly overpriced. And the price suggests it is a well designed instrument which has looked at different failure modes and mitigated them.
@@davoodnasehi I will yield to you to design a better product than this, for $20 or less.
120 USD for this toy is too much! Its overpriced s little bit?
Ok. What is this "toy" worth to you then? A toy, doesn't really solve a real world problem so what would you pay for it?
@@FelixRusu I consider my CurrentRanger an absolute bargain. With all the options plus the sickening 27% VAT imposed by EU, I ended up paying just over $200. This compact marvel will readily solve my childhood dream project challenge, the ultimate crystal radio instrumentation , a "final frontier" in Low Power. I am very happy and grateful for Felix's fabulously improved product, and I have no problem paying for it. Actually, I would have been willing to pay even more. It is all in the eye of the beholder. Call it a toy if you must, but "He who dies with the most/best toys wins". And I will have a blast playing with it.
Persze magyaroknak minden dolcsi-ár "drága". Akkor miért nem csinálsz egy jobbat, sokkal olcsóbban? Gyorsan meggazdagodhatsz! Vagy ez nem is olyan egyszerű, csak jártatjuk a szánkat? (GoogleTranslate from Hungarian if you don't get it)
@@DAVID999383 Thank you for your feedback, I'm happy to hear from yet another content user who can understand and see the value of CurrentRanger. I priced it to what I considered was a fair price given the complexity and time spent to develop and produce it, the parts are not cheap, the enclosures take almost 2 hours to print for 1 CR. The CR is NOT "made in china" but some people will never be happy unless everything costs $20 or cheaper.