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.
Hi @VictorG
You should RMA the FlightCore and we should replace it. Just mention this thread or place a link to it in the form:
https://www.modalai.com/pages/rma?_pos=1&_sid=190e46152&_ss=r
We do not yet have a replacement set of cables, under normal circumstances, it takes us 6-8 weeks to get more, so we are trying to see if we have any small batch in our inventory to hold us over and replace every bad cable that we shipped.
If you want to try to re-pin your cable for the interim (you will not need to send it back, we can just replace it when we get more), try this link:
https://docs.modalai.com/cable-userguides/ and at the bottom are tips for re-pinning
or you can just search youtube for s JST GH re-pin tutorial and I'm sure you'll find plenty of good techniques. All that is needed is tweezers.
@Martin-Lukac , @VictorG
Yes, we are working a replacement solution.
Exactly what @Martin-Lukac said is a temporary solution by swapping the conductors until we can source replacement cables. We might need a few weeks honestly.
Any HW that was compromised by this issue is an no-brainer replacement by my standards, and I will help ensure our production and operations team replaces any HW at jeopardy of this issue promptly. We have the HW in stock to replace, just not the USB cables as of yet.
We apologize for this issue. We actually had that batch of cables in stock for over 2 years and our sample lot from a different sealed bag in the same shipment that was tested did not experience this issue, so we were caught flat footed and we will put in better inspection processes to ensure this does not happen again.
Thanks!
Vinny
Hi @hula
YOU ARE CORRECT!
I found a whole bag of mis-wired MCBL-00010's in our inventory.
I'll work with our @Moderator to figure out a plan.
We will likely need to setup an email where any customer can let us know if they have offending cables and we will send replacements promptly.
Hi @hula
Interesting. I will investigate. The cable appears as it should according to our tech docs and every batch is sample tested but I will inspect further and respond tomorrow.
https://docs.modalai.com/cable-datasheets/#mcbl-00010
Thanks
Vinny
HI @Jetson-Nano
Your welcome. Apologies I cannot find anything blatantly wrong with your design at the document and layout level.
If your PCB still does not work after all these reviews and positive affirmations, then you may very well have a fabrication issue with your PCB.
The only way to verify that is to try your own net-by-net buzz-out using a DMM to ensure your netlist matches the expected schematic. If that all matches up, then you may be suffering from poor assembly/soldering. The socket for the lepton does require a reflow oven/line and cannot be hand soldered, unless you have an IR tray/heater and a way to deposit solder paste on the pads.
Any further debugging I could offer would require physical samples of the hardware to validate everything.
Hope that info helps!
Hi @Jetson-Nano I have reviewed your schematic again and your layout files.
I cannot see any reason why your design will not work.
The only suggestion I have is to increase your capacitors here to 1uF:
But, otherwise, your layout is OK (some improvements can be made, but nothing is detrimental):
The one issue I think I might have found is your reference designators do not match the schematic between the layout. So, I'm wondering if you are installing parts from the BOM in incorrect locations...
For example, the cap on the output of the LDO is "C6" in the layout, but "C7" in your schematic:
And, your resistors are also not in sync. R1 and R2 in the layout are for the Ic2 expander, but in the SCH, it is for your FLIR module and not R5/R6 as in the SCH:
and there are a few other examples. So, I just think perhaps your layout reference designators are not synced to your design.
J1 should be J2, and R3/R4 on the layout does not exist on the SCH.
So, maybe this is where your issue is. I'd recheck the annotation between SCH and Layout, and be sure you are installing all the correct parts in the correct places.
Hope this helped!
Keep us posted.
Thanks!
Hi @Jetson-Nano
I received your data package and will review it this evening.
Thanks!
Vinny
Hi @Michael-Mortensen
Please see the post to Victor about using the power module instead of just USB.
Let us know if that helps.
Thanks!
Hi @Martin-Lukac
Well that's not good. Your board will not work with that chip busted off like that.
Please use our RMA process and we'll get this assessed for for you:
https://www.modalai.com/pages/rma
Hi @VictorG
It is not unexpected to see some windows machines complain.
Our MCU does not enumerate as a normal USB device with current requirements reporting. So, some PCs will correctly complain.
Our goal with USB based powering is for ease of use with configuration. However, if this is posing a problem in your specific system, connect it as it would be required for a sUAS by using our power module and using an MCBL-00062 into the power port.
https://docs.modalai.com/flight-core-v2-power/#j13---voxl-power-module-v3-input
https://docs.modalai.com/cable-datasheets/#mcbl-00062
This will prevent pretty much all current draw on the USB port: https://docs.modalai.com/flight-core-datasheets-v2-functional-description/#power-supply-and-power-source-mux-details
Now as for the heating, we do know the MCU can get hot. It has no sleep modes or throttling in it when running PX4/etc, so it is not uncommon, but it will still work and is within specs. Some folks have used heatsinks or small fans with success to minimize the effect, such as: https://www.modalai.com/products/voxl-cooling-fan?_pos=1&_psq=fan&_ss=e&_v=1.0
Hope this helps explain things a bit.