Hi @Mihir-Bala
You will need a 2S minimum to satisfy all the requirements of our power module: https://docs.modalai.com/power-module-v3-datasheet/
Then, you need to do the math to support a 30Watt transient on power up... which equates to a ~5amp burst at the low end of the 2S cell ~6.4V.
So, if you have a 1,000mAh cell at 2S, that will require a 5C rating.
If you have a 2,000mAh cell, you need ~2.5C rating, and so on...
Hope this helped!
Hi @jacobcayetano1
Apologies for not updating some of the tech docs content about that test board we developed.
Here are some links:
https://docs.modalai.com/voxl2-dev-test-board/
That describes the board and provides schematics and other useful user info.
Since the test board is a very easy way to destroy your VOXL 2, we keep the sale of it on our Beta page to alert customers that it is an "at-risk" design since you can easily void your VOXL 2 warranties by over-stressing the VOXL2 and introducing ESD and other signal shorting risks.
That said, here is the purchase link:
https://www.modalai.com/pages/beta-voxl-2-b2b-breakout-board
It comes as a kit with many goodies for it's use including cables, a mounting case, and an SD card.
Now, as far as being able to use Microhard AND J5, we recommend using the standalone version ("dongle") of the Microhard board: https://www.modalai.com/collections/modems/products/mdk-m0048-2 since that will allow you to cascade it off any USB port we have (or one that you include in your design).
Here are some tips for designing a good USB port with our Voxl ecosystem: https://docs.modalai.com/expansion-design-guide/#usb-expansion-over-j3--j5
Should you go down the route of designing a custom VOXL 2 plug-in board, we will offer a courtesy review of your schematic to help you along! Feel free to tag me again when you are ready, and we will start an email exchange to share your data so you are not posting it on our forum (unless you wanted to).
Hope this helped.
Vinny
Hi @Gary-Holmgren
Yes, we did design VOXL 2 Mini to be powered by 1S capable source. But, we'll need @Alex-Kushleyev to respond regarding the MINI ESC and how that may need to be tuned for 1S operations.
For VOXL 2 Mini, here is the way it can work, and the few caveats to explain why we have not offered it yet in exactly that way. If I go in too deep on any electronics jargon, let me know and I'll try to clarify as needed 
The local 3.3V regulator for the UART, GNSS, and all other ports will start to drop-out at around 3.4V. So, even though the core electronics (Snapdragon, Memory, Cameras, USB) will work down to 3.2V, some of our extra circuits will not be happy. If you are powering modules from our 3.3V supply, and they can operate at slightly lower, like 3.2V or 3.1V, and you use our 3.3V as the VDDIO ref, then all is good there.
Our 5V boost circuit likes higher voltages. At 3.8V VBATT in, we can supply ~900mA of VBUS (to mimic USB3 VBUS specs). However, as that input VBATT voltage goes down, so will the capacity of that supply. Also, I have a UVLO setting on that rail to trigger the 5V boost to turn OFF if VBAT drops below 2.5V to prevent 1S battery continual drainage (deep discharge) in the event you disable the flight control stuff, but forget to disconnect the battery. However, the ramp ON has a very large hysteresis and it triggers at ~3.5V. So, if you try to start a power ON with less than 3.6V, that 5V boost may never turn ON. Now, if you are not using VBUS, or the 5V on the J19 connector, then it's a do-not-care. But, your ToF use case will require it....
TOF is not easy on VOXL 2 Mini, especially the new V2 one. Since we only have that 900mA of 5V (less at lower voltages), the ToF circuit may get starved of it's needed 5V if you start to use other stuff, like USB or lower input VBATT. So, we would only caution you to use 1 ToF module at max, and be prepared to lower exposure and frame rates at VBAT < 3.8V. Our ToF modules use that 5V to generate a local 3.3V, so we do get some power conversion gains, but we just have not done it yet on V2 Mini to capture all the other side effects.
Thermal, if you are using our Fan connector, that is powered by that same 5V supply IN mentioned above. So, if that does start to shut down, you'll get a fan OFF condition (possibly ON/OFF throttling like a forced PWM if the 5V comes back on), triggering thermal rise compared to the current 100% duty cycle ON as it is now.
Unplanned/Untested Software responses at VBAT <3.8V. As stated, we have not tested this config. The Snapdragon parts are very complex SoCs. When power input starts to go below a certain threshold, the underlying Power MGMT IC's (PMICs) will start to throw interrupts. I think the first one by default is around 3.3V VBATT, but they change based on platforms and chips. So, as we start to approach the "dead battery" SOC%, the system itself may start to react differently and we have not characterized that at all for our builds. It is electrically spec'd to operate, but SW may start nagging and doing weird stuff, like turning off functions such as cameras for example to conserve power.
Motor noise!!! This is the biggest one... 1S motors will draw a lot of current to equal similar power demands of higher 2S+ rated motors (there is some V*I correlation here to motor power, so the lower the V, the higher the I). This will result in a lot of noise on the VBATT power rail. These transients can go not only low (droop, triggering resets, 5V OFF, etc) but also too HIGH (back EMF, energy dumps, etc...) potentially damaging components on V2 Mini's front end power system. V2 Mini ABS MAX voltage in is 6V, at which point the PMICs will be damaged. This is the single biggest reason we have not tried to connect a battery directly to our electronics, and always opt to have some type of nice DC/DC to provide solid line-regulation protection. So, if you try to use a direct 1S VBAT, you will need a really good motor-noise transient protection, maybe even a fast acting Zener diode, set to ~5.6V or so. On a side note, we just started including a 5.6V Zener on a new Spin of V2 mini we are working on, but existing M0104 V2 Minis do NOT have that 5.6V zener. Details on a new V2 Mini will follow in the up-coming months, as teased here: https://docs.modalai.com/voxl2-mini-connectors/#j3-usb-3-10-pin
Those are my first thoughts... If I think of anything else, I will let you know.
I think it is doable.... V2 Mini was designed with micro-quads in mind, but there is some planning and design considerations that need to be done. We can help you along with the HW side of stuff, but I can't promise we'll have any SW support for issues possibly related to low VBAT in since we have no system to check against or develop with. That is why we only use 2S+ in our platforms (currently).
Hope this helped!
Hi Nikhil,
Sorry for our delayed response on this. I just recently joined our forum to help out with more HW centric question.
As Chad mentioned, this does require HW mods if you do not want the SW driver timestamp method (which would be our recommendation/preference).
The Lepton signal VSYNC (on GPIO3 most likely is what you are referring to) is running at the VIO voltage of 2.8V to 3.1V per Lepton specs. Our camera sensors are MIPI based, and as such all of those I/Os are at 1.8V, so a level translator would be required which makes connecting these a bit tricky, especially if you need bi-directional support with another sync controller/snoop device. This would need to be something done on a custom interface between the Lepton and the stereo sensors. We do not have such module but would be happy to give further guidance if you need it.
Thanks!
Vinny
@Ansel-Misfeldt Hi,
The approach we will take for CANBUS right now is similar to what we have. That is, to add CANBUS, it requires the use of a FlightCore Flight Controller. So, with Voxl1, you have Voxl-Flight which integrates the FlightCore, or you add on Flight Core independantly.
For Voxl2, you can still use a FlightCore, but we have some exciting news coming soon for a newer improved FlightCore, we will likely call it FlightCore V2
It will retain CANBUS functionality but has a slew of other upgrades and user improvements added in, all in the same form-factor as FCv1.
Our Docs portal is just about ready for launch and I think we did a better job up-front on this one to help our customers get running quickly.
Stay tuned, we should be posting it for sale in the up-coming days!!
Hi @serviceberry
From a HW viewpoint (I am HW team) that sounds reasonable to use the hub the way you suggest. But I know for a fact from personal experience the Boson's are very dependent on VBUS rise times, and a very fast rising 5V supply may not allow it to enumerate properly. We have had an instance in the past where one particular VBUS port rose really fast, and the Boson did not enumerate until we slowed it down. It's one of those situations that may require testing to check. Our J3 10-pin host port has a nice moderate rise time that allows Boson to enumerate. So, when using a Hub, check the VBUS rise times compared to J3.
I do NOT expect J9 USB-C OTG port to work with Boson.
The Snapdragon SOC is very smart, and when in OTG mode, it will not provide more than 500mA to any device that enumerates as USB2 which I am lead to believe how the Boson enumerates. if the Boson could enumerate as a USB3 device and the drivers were all present in the Kernel for this, the Snapdragon will give it 900mA over VBUS letting it boot but I think this is a non-starter without the Boson being able to do that.
Our Boson kits use USB2 only and we provide 1A support to enable them to work without requiring enumeration to negotiate more current, hence why they work on the J3 ports and other expansion board ports that have more than 500mA: https://docs.modalai.com/expansion-design-guide/#usb-expansion-over-j3--j5
Hi @dlee
All of our Doodle configs are only using USB2, not UART.
Hope that answers your questions.
Thanks!
Hi @John-Nomikos
Have you confirmed the issue we pointed to in the other forum post?
https://forum.modalai.com/topic/1356/sentinel-drone-randomly-reboots?_=1673383475709
Do you have Kapton or another insulating tape you can place on the J5 120-pin B2B connector on Voxl2 to help confirm the Microhard is not touching J5? We've seen it first hand that it triggers resets.
I doubt all 3 MCBL-00001 are all bad on you (although we do know they go bad fast from users pulling them out by the cable wires instead of the plastic shroud, but that's another issue).
Let us know.
Thanks!
Hi @dougmiller
If your VOXL 2 Mini is TrustZone Configured for UART over J10, then yes, there are 2 pins available as inputs.
https://docs.modalai.com/voxl2-mini-connectors/#j10---external-uart
You can see GPIO_40, GPIO_46 and GPIO_64 are input capable.
GPIO_40 and GPIO_64 are able to be configured to do wake events in the SoC so they have extra configuration to route to a power manager. Depending on how you write your IRQ routine, that may or may not help.
Hope this helps!
Hi @jacobcayetano1
Our Power Module is proven to deliver 30W continuous over the full industrial temperature range.
I'd be shocked if you can find a better module with all of it's features out there for this price point.
I encourage you to stress test it using a load box and you'll see how reliable it is. I'm happy to share a few of our validation plots if you wish. We also unit test every unit with a 3Amp load (15W) before shipping.
Let me know if you have any other concerns about the power module.
To add to what our Moderator has posted, the QGC "Avionics Power Low" feature and warning is useless. The ADCs on STMicro parts are frankly terrible, plain and simple. That is why we use a 16-bit INA231 on the power module for current measurement and reporting.
Additionally, You cannot power the FCv2 over USB fully featured as noted here:
https://docs.modalai.com/flight-core-datasheets-v2-functional-description/#power-supply-and-power-source-mux-details
That USB power option is provided as a convenience for programming w/o a bulky battery.
@Alex-Kushleyev @Morten-Nissov , The team just posted the M0172 for sale.
Sorry for the delays....
https://www.modalai.com/products/mdk-m0172-1-00
Hi @serviceberry
I happened to stumble on your post here, sorry it looks like no one ever responded to you.
Is your HW still in error?
Can you confirm how you are powering the VOXL 2 mini, and if anything changed before this issue?
The two ICs you show that are smoking hot are interesting.
The one at 156C is the level translator for our I2C bus on the power connector.
Are you sure you have pins 1 and 2 as power, and not pins 3 & 4? If pins 3 & 4 were accidentally used to power the VOXL 2 Mini, this chip would indeed see the brunt of that issue.
The other chip heating up may just be secondary due to the other failure since that chip is downstream of this one for powering the board from the voltage impacted.
Looking forward to your response and sorry again no one responded (or did you submit a second case??)
Thanks!
@shawn_ricardo And one more point I wanted to make about the cable...
this is our solution which we know works well:
https://docs.modalai.com/cable-datasheets/#mcbl-00085
However, our only design that can power a doodle at full specs is M0130: https://www.modalai.com/collections/expansion-board/products/m0130-3?variant=48186331693360
and under that combination of HW and cable, we see no issues, so I'm not inclined to think there are any SW issues going on here.
Hi @shawn_ricardo
I was thinking a bit more about this and I'm even more confident it's most likely a ground loop issue. When you use a PC, it is plugged into the same wall-ground connection as the 5V power supply, so there is no ground loop between the PC and the Doodle (they share the same common ground from your house/lab/office). However, with our drones, that GND connection is isolated due to the battery. If you are using a bench power supply instead of a battery, then the ground has a (typically) isolated path to push through since most benchtop supplies are isolated from wall power to the load output for replacing batteries (i.e.: you need to NOT have the negative terminal shorted to Earth GND for battery powered electronics replacement supplies).
So, I'm even more confident you should try a power module fed by whatever supply is powering your Starling.
The other smaller thing I thought of could be related is turn-on timing. Some devices, Boson in particular (though I have not heard this with Doodle) are very picky with power up timing and will not enumerate if VBUS is too fast to rise, or if some devices turn on before their host. I'm curious if the turn on timing between the Doodle and the PC is less of a concern (likely the USB port is going into a hub internal to your PC), whereas with us on a Starling, it's direct to the Snapdragon (no Hub) and the timing of it may be more sensitive. The way to check for this is to experiment with turning on the doodle power at various stages (before Starling, after Starling, after Starling for a long wait, and even "with" Starling) and see if that makes a difference. If that changes things, then we have a timing issue that may be addressed by a SW enabled power supply based on when the enumeration is successful....
But, I'd still go with the power module as a priority, since that is what is needed anyway for flight. Might as well test as you will fly.
Keep us posted.
Thanks!
Hi @SKA
Alex's instincts are correct, we do not have a smaller plug in board for just tracking in a synce'd config. We only had an M0155 for one image sensor for a while, so your best bet is what Alex said and get the new M0188 for VOXL 2 Mini (VOXL 2 uses M0173, whereas VOXL 2 Mini uses M0188)
It's quite cost competitive for what it does!!
https://www.modalai.com/collections/all/products/m0188
Hi @shawn_ricardo
You are lucky that works on a windows PC. The USB cabling is in need of improving to work reliably. Please shorten the USB data lines, and ideally keep them twisted pair.
Our system does not buffer our USB lines on a Starling but I bet many full sized PC's do.
Also, we do not know the GND connections on doodle for power vs USB, but I bet we have a ground loop here.
The power supply for the drone and radio need to have the same ground at some point, and I cannot tell if that is done here.
Third, there is no way to confirm if the wall adapter is indeed providing 5V @ 3A since there is no USB bus to negotiate that current. Without any negotiation of a USB Host/Charger and a peripheral, you are most likely only getting 500mA.
The better test is to use a power module, like our V3 https://www.modalai.com/collections/cables-1/products/mdk-m0041-1?variant=46923853955376, and use that to create the 5V for Doodle using the same source that is powering your Starling. You'll eventually be trying to fly this right? Unplug from the wall adapter and try it the way you intend and I have a feeling things will be better.
Hi @dougmiller
If your VOXL 2 Mini is TrustZone Configured for UART over J10, then yes, there are 2 pins available as inputs.
https://docs.modalai.com/voxl2-mini-connectors/#j10---external-uart
You can see GPIO_40, GPIO_46 and GPIO_64 are input capable.
GPIO_40 and GPIO_64 are able to be configured to do wake events in the SoC so they have extra configuration to route to a power manager. Depending on how you write your IRQ routine, that may or may not help.
Hope this helps!
Hi @yardy
Are you using the jumper blocks J14.15/J14.17 to JP1.10/JP1.12 respectively for QUP_19?
That will result in 3.3V RX/TX signals at J9 on M0144.
Just want to clarify so that SW is not chasing any red herrings.
Thanks!
Hi @Hung-Pham
All of our products are 0-70C, unless we state otherwise.
Thanks!
Vinny
Hi @JANG
The only time a power module is damaged is when a power supply is used to power the system and the motors are spun up, creating a voltage spike on the input rail that exceeds 28V, not a battery. So, this overall is very surprising to me.
You are welcome to use any 5V source for FCv2. It does not need much power (maybe 1-2Amps total) so our power module is overkill for a FCv2, but it helps by providing current and voltage readings to to PX4 or you FC SW of choice.