Hi. There was some people who wanted me to take a closer look at the Energy Micro Tiny Gecko board Power It Up Hook it up, do some measurements. Sounds like a good idea. Let's go now.

There were a few people who commented on the mark on the LCD here. it's not a mark at all, it's just the Tada the uh plastic film protecting the display. Now let's actually power the thing up and uh, see what happens? Woohoo! Get latest software from Energymicro.com Not too keen on the uh segmented display here. Oh, it's got a nice little, um, fancy uh Target display there custom display and it's jumped straight into what looks like the capsense slider thing.

so let's play around with that way. Yeah, it does work. Let's touch it over here and you'll notice that that Dash disappears and then it's giving you a count which is presumably the count position on the slider. And if I slide my finger along there.

not only does that bar graph rotational bar graph go up, but uh, cap sense touch also goes along it. Scrolls the text cap sense demo. It's a little bit touchy pardon the pun, but uh, you can see that works a treat and if you push the button here, you end up in a slider thing. which actually, well, it slides the segments along the display like that instead of scrolling the text and uh, if you do it again, it's got uh, looks like a pad zero I assume refers to that pad and you can see the value change.

And if I touch these pads over here, it doesn't really change at all. and I can swap between pad one if I touch pad one there, the value changes. if I touch pad zero doesn't really change that much. So there you go.

It looks like it comes up pre-loaded with only a capsense demo. Could have something else but I can't find it. There's one thing I didn't see in the original look at. this was this LC sensor here.

it's a little inductor and it can detect uh, nearby magnetic fields and uh, but don't get too excited. Uh, you're not going to be able to take this thing out and find Laci's Reef or anything like that. Uh, it's only got a detection range of a couple of millimeters I believe and I Did complain that there wasn't a gecko on the board and uh, sure enough, previous versions of the board have had a gecko but the one I've got, they're taking it off but on the chip there you can see cute little gecko laser etched onto the chip I Love it and this switch down here turns it off and on from the battery power. but let's hook it up to the USB and see what we get.

Tada ping and it Powers it alternatively from the USB and we've got our Sega Jlink debugger LEDs going there. So let's get this software a try and the only documentation you get in the box is this quick start guide which says go to Energymicro.com Simplicity Well let's give it a try and bingo You type in Energymicro.com Simplicity and you get this page a stepbystep, uh procedure to run the software looks pretty easy. Let's give it a try and here it is Simplicity Studio Free download and it it appears that uh, they've got different uh demo boards. This is the tiny Geo but they have other ones with large uh uh, RGB type uh displays on them and uh, looks like the software would support all of those.

So let's download it and there's a whole bunch of demo programs. Beautiful! Let's give it a try and I won't bore you with the entire download process. It was a 7meg download, very reasonable size and it popped up with this. The following recommended packages are not installed: Do you wish to install them? Eh? Better On second thought, screw that it's taking too long.

so I'm going to cancel that and I'll see what happens when I plug in the board and it looks like you have to install everything. So uh, don't just uh, do what I did and cancel it. Make sure you install all the options and here we go. We get the uh, energy aware, uh stuff because this uh, tiny Gecko board actually has any energy uh, measurement built in.

It's effectively got like a little uh microcurrent built into it. It can, um has two different ranges that can actually uh, record the Uh CPU measure and Um transmit back and graph the CPU Uh current for uh, various Uh ranges, and Uh Power Cycles. So we'll give that a try. and we've got app Notes We got examples, kit, documentation, demos, videos, all sorts of things.

looks pretty good. Um, here's all the Uh documentation. so let's take a look at and there's not much on the data sheet, but it does tell you here. it has 0.1 microamps or 100 nanoamps to 50 amps measurement range of the measures, the voltage and the current of the V MCU rail.

So that measuring voltage and current allows you to uh calculate how much Uh Power Because the thing with Uh measuring and Uh characterizing and comparing the Uh power consumption of different microcontrollers is just that. you have to do power. You can't necessarily go on, uh, just the current figures because it's dependent upon the supply voltage. Let's take a look at the user manual here.

it's 41. Pages seems fairly, uh, comprehensive. and if we take a look at the Uh block diagram, there's the uh, segmented uh display. Look at the tiny little gecko.

They've got a gecko symbol on the display. haven't figured out how to get that one up yet, but uh, that's nice. It's got a little battery bar graph and uh, the various circular things. plus the segmented display as well.

And like a timer. Uh display up here too. And there's Milliamps Microamps. So maybe if we run some of the Power demo apps, it'll actually, uh, tell us, um, how much power is being consumed.

That would be really nice. And there's the rest of the block diagram. the touch slider, couple of push buttons, the ambient light sensor, the LC sensor as I mentioned, uh, and some debug, uh stuff, and uh, the optional opamp and that's about it. But uh, what? I'm really interested with this thing is the Uh power management capability.

and if we click on the demos button here, what do we get? We get a whole bunch of demos and there's a here we go. a demo of different energy modes. Let's have a look at that. So here it is.

They got the instructions here. Uh, it. Basically you just cut and paste this example code here a tiny amount. you just put it in your main.

uh thing. call up this function once by the looks of it at the start and it looks like it gives you the diff the energy profile of the different functions. Look at that main is taking 98% of the Uh power I'm assuming yep, energy in Microj? There it is and that's brilliant. And presumably if you got a big complex app, you can see which Uh functions are taking the most amount of power.

I'm really liking this because doing this sort of stuff with a regular microcontroller which doesn't have uh the build-in uh, support for doing something like this would is usually uh, very, uh, difficult and ad hoc. You've got to know how much uh instruction time is spent in each uh, sub, routine, and uh function and then uh, try and measure your uh battery consumption. But here you can actually do it directly on the demo board. It looks pretty trivial.

Wow, this is powerful Now what I did is I Clicked on the main function and this looks like uh, the demo program. it's running uh Em mode. C and uh, you can see the code in here and it's drawing down the bottom here. 5.92 milliamps at 3.3 Vols But but uh I don't uh off hand here um I don't know what frequency that's running at or what it's actually uh doing at the moment.

but uh, you can. Actually it looks like you can go in and you can uh, debug your code directly in this uh, energy aware profile or window. and if you go into the energy aware battery thing here, it gives you uh a a tool which allows you to estimate the battery life of your program. I'm running a demo um here and it's a C.

You can choose your Um cell Alkaline Able a AAA or your Cr20 32s for example, Lithium cells number in parallel, number in series and uh, it can um apparently give you a profile. boom of there's the battery uh curve like that and it can show you the minimum Uh where you set your minimum operating uh voltage at presumably you can change. Uh, that figure. Average current might be 2.8 microamps here.

Estimated system operating time: 8 years. There you go. The rated capacity is on. That's a CR 2032 cell.

8 years at 2.8 microamps? That's rather neat. Uh, you'd have to like, you can actually load in, presumably load in your actual Uh program and it will, um, actually estimate it based on your real application. I'm just running one of the simulation demos here, but this looks really neat. They've really put a lot of effort into Uh Energy Management on these um, Gecko microcontrollers.

It seems to uh, uh, what? actually um sets them apart. So I Like this man, this is neat. I think I might uh this is kind of swaying me towards using an Energy Micro Uh device in my Uh Microw watch. Mark I I Think just because the tools are neat and if we go into the Energy Aware Designer program here, this allows you to uh, generate Uh code.

Um, the initialization. C Code for various packages and various peripherals and things like that. So you go up here, you choose your device from all those and all the different Uh types of packages and then we can enable things like enable our realtime clock bang. We want to do that.

We want some Adc's Yep, we got looks like four to choose from in this particular package. Let's enable. You know, four channels of those and uh oh yeah? I Squar C I want one of those and uh, looks like you can get three different uh pin locations for the yeah, there we go. You can select which pins you want a neat I like that and oh, actually, it tells you it conflicts I'm assuming the red means that they've conflicted with something else.

Ah, excellent. All right. I Like that. Otherwise, let's put them up here and we enable that and you can do that with any of the internal peripherals.

We got the Uh timer, the interrupts, and stuff like that and you can generate uh PDF reports for this sort of thing. we can do the uh, we can show pin Matrix views. There we go. That's a matrix kind of view.

Once again, we can save the Uh PDF for that. It's got a button down here, but let's get out of that and let's generate our C code. Bingo There it is. We've got our C code for initializing this particular device.

Um, looks like it's set up as 14 MHz high frequency clock Gpio. There's a um, the Pio open drain with pullup and filter and all that. There's the ADC the I, Squ C or your initialized code is there for you I've got to say that is one of the better Uh configuration tools I've seen from uh, any vendor. That's very nice cuz lot lot of the pain involved with microcontrollers is just getting the damn things up and running and uh, getting the modules enabled cuz you first write your program and then you know it doesn't work.

First go, you're scratching your head wondering why cuz you haven't enabled some pin or, uh, some register or something like that. This just allows you to do it in a nice graphical user interface and make sure you've got it right. Neat! And let's try out the Energy Aware Commander option which apparently allows you to download uh, firmware and do stuff like that. So let's connect.

it's we're connected to our tiny gecko uh starter kit. uh, where in we can go to various debug modes USB address the chip type we've got on the board, there, the chip revision so it's read the uh silicon ID code. Out of that we can Flash in uh, there we go. We can Flash in various stuff so that's like a little uh programmer is it? That's almost like a standalone programmer option I think so let's go look in the demos.

There we go, we can download the demos. Blink the lead. Woohoo! Try different Eny Energy Mode demo using the LCD Let's try that, start and it resets and that's pretty quick. And yep, we've got something on our LCD When you press the reset button here, you can see that it's uh uh in 32 mahz mode and you can actually cycle through different modes 30 2 khz Crystal and when you do that, that will plus the RTC the real time clock.

So you've got all these different modes that you can measure and in the background you'll be able to see the Uh graph changing. So let's give that a try. So let's take a look at that. You can see it's drawing in 5.92 milliamps now because it's in the Uh 32 megahertz mode.

so that's what is drawing at 32 mahz 5 almost 6 milliamps at 3.3 Vols But if we change that mode, we can see it. Let's go to 32 khz and see what happens there. and Bang! It's dropped and you can see all the different functions down here where it's uh, taking the power consumption for this application. All right, This is really cool.

Check this out. I'll switch it to 32 khz mode. There it is and you should find the current consumption. Bang drops all the way down to 1 microamp because we've got logarithmic scale there and if I choose the RTC plus LCD option here.

there it is. it'll leave the LCD on and there we go. It takes about oh I don't know 6 7 microamps or something like that to drive that segmented um LCD plus the Um plus to have the 32 khz realtime Crystal uh working at the same time, the touch slider doesn't seem to be active there at all. but uh, there you go.

That's how much energy is required. Oh, you can see if I press the button. There we go. You can see just the slight increase in, uh, energy consumption.

and you need to take that into account in your designs. If you've got a low value pullup resistor on your switch and the user's pressing that, it's taking a little gulp of current every time you actually do that. So um, you really have to optimize the value of your pullup resistors on those user switches. And if we go and take a look at the application notes here, they're fairly comprehensive.

like there's uh, fat on an SD card, Ethernet, all the good stuff AES Cipher modes, and uh, all sorts of things. There's low energy Arts I like it. but let's go in and actually see. And here's a list of the five different energy modes we saw in the example uh, demo that we were just running.

So mode zero is where these CPUs run in flat chat and it's just, uh, you know, everything's cheing as much power as possible. And then there's sleep mode energy mode one where basically the CPU is disabled. but uh, any of the any of the peripherals using the here we go, wait for it, the peripheral reflex system PRS woohoo, and the Dma um, it can actually do autonomous operations without powering up the CPU For example, the timer May repeatedly trigger an ADC conversion at a given instance. When the conversion is complete, the results moveed to Dma to RAM and uh.

When a given number of conversions have been performed, the Dma then wakes up the CPU using interrupt so you can basically uh, data log by the sounds of it, data log uh things from the ADC without using and powering up the CPU at all brilliant. Um, and then there's deep sleep and energy. Mode 2 means that there's no high frequency clocks running at all. only like uh, the low power 32 khz clock for doing I squ C stuff LCD uh uh operations, uart operations, analog comparators, realtime clocks, and some basic Gpio uh, checkin.

and mode three is the stop mode and uh, that uh differs from sleep mode in that no oscillator apart from the Watch Dog is actually running at all, even the low frequency uh one. So in, even in this mode, you can still do an I squar C uh address check, watch doog, of course. Um, you can do Uh pin interrupts, analog comparators, and Gpio interrupts without uh, any internal clock running and energy Mode number four is complete shut off mode where it can draw. so they claim as little as 20 nanoamps and the only way to exit that mode and get back to operation is to uh reset.

the is to trigger the reset line or uh cycle the power. but this CLA CL of 20 nanoamps I think we might be able to check that H Now as a bit of a Uh industry comparison here: I've got it uh running in the LCD plus um RTC mode. So um, trust me, the LCD is actually uh displaying something here and it's running the real time clock as well. and as you can see, it's drawing around about 5 micr or something like that cuz remember, this is a logarithmic um uh ya axis here.

but if we compare that 5 microamps running with, say a microchip, uh, pick 32 MX um series micro. So I'm comparing 1 32-bit micro to another not quite um, apples and apples but you know, reasonably close in the low power RC mode at 32 khz, it's going to be drawing roughly um 100 microamps typical at 3.3 volts. So this thing's uh, driving an LCD as well as running the uh real time clock. but I guess the processor is not continuously running at 32 khz here.

but you get the idea of uh, of what you can actually uh do with just you know, 10 microamps or something like that. There's hardly anything uh being used there at all sniff of an oily rag. And of course, if you put the Uh demo in energy mode uh two which are claims on the LCD that it's 32 khz. So I presume.

uh, the processor is running at 32 KZ It may not be running continuously, but as you can see, it draws um under one microamp. Amazing! And if we use Energy Mode 2 with the real time clock turned on, you can see it's now just a smidgen on or smidgen over one microamp. and again, if we choose the P 32 MX Series Micro is an industry comparison for an equivalent 32-bit micro with the Um Real Time Clock Plus the timer one with the 32 khz Crystal There we go. 23 microamps typical 50 microamps Max So the Energy Micro Um using its Um Arm Cortex M3 plus all its Uh Energy Management uh capability low power stuff.

it draws at 123 of that only one microamp and I've put the board into energy Mode 4 which is complete shutdown mode and as you can see, we're down in the noise under 100 nanoamps there. It's not really accurate down here. it might be say 10 nanas average, but really, it's not accurate at all. So let's see if we can get some more accurate measurements of that.

And if you read the user manual here, it actually tells you what it's capable of measuring. Here it is from 0.1 microamps to 50 milliamps and does add in to different Uh ranges and uh, it can go down to 100 nanoamps resolution. but resolution is different to accuracy. But the built-in Uh Power measurement uh capability.

You know it's probably good enough for most applications, but but I think we'll just uh, double check that and uh, see if we can measure it ourselves. And if we take a look at the schematic here and see how it's doing, the MCU Power Uh Current Sense: This is the circuit it's using a linear Technologies LTC 6102 Zero Drift Precision Current Sense IC In fact, it's got two of them for one for range one and one for range to as well. and uh, it's It's not a bad Uh device at all, and it's a Current Sense amplifier. And if we take a look up here, we've got an LP 3982 that's a low Dropout Uh voltage regulator for the Uh for the supply for the CPU and 5 Vols in Uh 3.3 Vols out.

And there's our current shunt resistor the Uh 4 R7 there. and of course it Taps off those two values down into the Current Sense amplifier down here for both Uh ranges and then the output Uh is Switched in. Here there's our coin cell battery and our output there goes to our V MCU in there. so that goes to the Um to a specific pin which goes onto the Uh microcontroller which is uh just for the MCU core so we can measure the power consumption of that.

And by looking at this, this is some sort of Uh connector or some sort of test pad. If we look at R704 here, zero Ohm resistor, we should be able to get in there and use that Um, if we take desolder that resistor, we should be able to uh, break into that with my Uh microcurrent adapter and actually measure the current taken by the MCU pin. Let's give it a go. now.

if we take a look at our board here, we can see our 4.7 Ohm Uh current shunt resistor there with the Uh two resistors going off into the two um, uh, current shunt uh amplifier chips. And here's our St700 connector down here. and that's R704. So if we desolder that sucker, we should be able to get in there and measure the current consumption really nicely using this header connector.

I Love it And Bingo! we now have a current Shun in there. We can just take that out and we can measure our microcontroller power consumption. They were thinking when they designed this because it's Energy Micro and they want you to be able to, um, measure the energy that this micro is using. Go figure.

and what I've got here now is my microcurrent on the milliamp range at the moment. Hooked in jumping into that um, uh, current shunt header uh connector up there and I've got the output connected to the fluke on Molt range. so 1 Uh molt equals 1 milliamps. So it's drawing 4.8 milliamps at the moment and that's in its default uh 32 mahz uh mode.

So if we let that go down, it's 2.8 switches off. Bang! It goes into the mode so we can measure the different mod modes Now by just cycling through and selecting the mode we want. Let's go to that 32k range mode, go down there and uh, let's measure the consumption of that. We're only talking there.

it is that one microamp. but of course we can get much better resolution on that. But by switching to our Nano amp range down here and then taking it up and bingo, there we go. 990 odd milliamps is jumping around.

We could smooth that out if we wanted to, but it's drawing around that one microamp figure now. of course. the big question is what happens in that um, uh, power mode four where it's completely shut down? Well, we'll find out in a second. Bingo it's dropped down to nothing.

Let's switch this down to our nanoamp range and Uh. 1 Molt, it's drawing. No, that's a bit disappointed. it's drawing 100.

Oh no, it's going down there. we go. So obviously something is charged up there and uh, it's got to go down. So I might wait a bit and see what that gets down to.

And there you go. When we power it from the Uh USB input like this, it actually enables the en uh, some of the Uh Energy Management stuff and some of the analog switches and things. So you really need to power it from the USB to get that capability. And there we go.

It's about 165 or 160 odd. Uh. nanoamps? Uh, power consumption, energy Micr claim around uh 20 Nan in energy mode for that complete shutdown mode. So I Decided to have a look at the schematic again and see what is on that V MCU pin and it turns out there it is.

There's another device on there. it's a Ts3a 4751 and that's a Texas Instruments um uh single Supply uh quad uh analog switch and if you go down here and take a look at its current consumption, there it is at 25 see which is it's near enough to that here here in the lab it's around about well, no actually it's saying that's a maximum figure there a maximum figure of 75 uh nanoamp so you know, but that could vary uh, quite significantly I'm sure. but at least a good part of that current is uh coming from this device. So then what that's doing is paing this analog uh switch here which has the um JTAG uh signals going through it.

So I'm not sure why powering that device? Um, well I guess you've got to uh measure It allows you to measure the MCU power consumption uh during day J tag art, debug operations I suppose. But there you go. there's the V MCU art Target and the V MCU debug. There are the things that go down and power the microcontroller so it looks like that's a bit of I don't know if it's it's not really an oversight I guess but it's just a design.

uh, thing that doesn't allow you to um, uh, accurately measure the just the raw core. uh, power consumption of this thing and Bingo I Hate these moldy sheet schematics. They're rather confusing. but M V MCU not only Powers Um, this analog switch here, but there's another analog switch here.

It is Vmc also Powers U 695 B there. So there's another device. so there's two of those devices there at Uh 75. uh, micro, 75 nanoamps, uh maximum.

Which brings us to 150 and we're measuring 160. So really, um, it? You know it. It comes out in the end. it works.

It's the micro is around about, um, 20 nanoamp, 10 or 20 nanoamps or so according to um, the data sheets. But this isn't going to be very precise because you've got, uh, you're measuring, uh, the power consumption of these devices as well. These analog switch, which is going to vary with temperature and the micro is going to vary with temperature as well. So unfortunately, that Um jumper on there does allow us to measure the current, but there's that residual in there.

Um, it allows you to measure the current of your micro under test except for that very deep sleep mode where you can't really characterize the 20 nanoamps. What a bummer. but I'm not sure it will actually uh, meet its spec I'm sure they've done their homework and they've done their isolated measurements there, but that's still handy for uh, developing your applications just using that uh jumper, uh, shunt there and you can measure the in circuit current or you can do it using the onboard Energy Management thing. So there you go.

I Rather like that. that's a bit of playing around with the Energy Micro EFM 32 Tiny Gecko startic it and I Really? I think I Like these devices, they live up to their name Energy Micro. They're all about measuring the energy consumption in different energy modes of these microcontrollers. So next time you're in the market for uh, one of these for a low power micro, check them out.

That's Energy Micro. So if you like the video, please give it a thumbs up. and uh, you can discuss it all on the Forum Catch you next time and this is rather neat. I've got it in LCD mode here and I disconnect the power, break it and it fades away a bit because it's still storing energy in the bypass caps and that's what's still powering the circuit.

Still keeps it alive for quite a few seconds and even when you think it's dead, it can come back. Beautiful!.