ModalAI Forum

@Vinny Understood, but this affects our schematic design. We simply need to understand the purpose of pin 25, “3.8V Primary ‘Phone’ Power (mimics nominal 1S),” and how it should be connected. This information is not provided in the M0161 datasheet.

Assuming your Stinger SKU contains an ExpressLRS modem (ModalAI M0184 Gemini RX), you will want to follow the ExpressLRS Binding procedures. Firstly, to put the receiver into "binding" mode, you'll want to either press the bind button for at least 1.5 seconds, and you must do this at least a few seconds after the battery has been inserted (or anytime later). You can also put the receiver into binding mode by powering on and off the Stinger 3 times quickly, though this can be unreliable. You will also need to make sure your transmitter is compatible with the receiver, and in a compatible mode. The M0184 by default comes with firmware based on ELRS 3, so you will need to verify that your GX12's internal ExpressLRS firmware is also on major version 3, otherwise you will need to downgrade to V3. Furthermore, the GX12 comes with a dual-band transmitter which supports 2.4GHz and 915MHz operation. To work with the M0184 you must make sure the selected "RF Band" parameter is "915 MHz", and the packet rate is 50 Hz 100 Hz, or 200 Hz. Other packet rates are not supported on the older modem in the M0184.

Hi @김다연 The INA260 is not supported. M0041 is designed around the INA231 and our power monitoring software expects that part. The two are not drop-in compatible. They differ in register map, device ID, and the INA260 has an integrated shunt rather than the external shunt the M0041 uses, so it is a board change as well as a driver change. Supporting it would require a new driver and a new M0041 variant, neither of which exist. If you need power monitoring on VOXL 2, use M0041 as designed, or take battery voltage and current telemetry from our ESCs, which report it over the ESC UART.

Hi @김다연 Both are enabled by default. If a QUP appears in the table with a device node, it is enabled in the shipped image. No device tree changes or additional hardware configuration required. UART7, J3 pins 3 and 5, /dev/ttyHS1, sys image 1.3+ UART13, J5 pins 97 and 98, /dev/ttyHS3, sys image 1.5+ Full table: https://docs.modalai.com/voxl2-qups/ Note UART13 requires system image 1.5 or newer. Check voxl-version on your unit before wiring it up.

Hi @alex-z-1 Here is the STEP for the front tracking mount: https://storage.googleapis.com/modalai_public/modal_drawings/D0013_Front Tracking Mount.step Note this is the V1 plastic. The V1 Stinger has been EOL for some time, so this came out of archived CAD rather than a current release. One observation from your photos: the film is still on the battery pad. That likely contributed to the battery stop breaking, though it would not have saved the camera housing. Let us know if this helps!

Hi @vinny thank you. I will wait to hear from you.

@jake_eizy , I ran a quick model to predict the currents and ESC loss for the 12x6 prop. our database did not have the exact model for this prop, so there was a predicted model and an actual modal published by APC. I hope this helps. I can also provide some more details on best practices for testing new motors / props to reduce the chance of a failure while bench testing. I may be able to put that together into updated test scripts that we already have. Alex [image: 1793824122065-3110_10x5_15x6_prop_compare.png]

Hi @czarsimon Flickering is not acceptable and it is worth chasing before you fly it. DS1 is driven by the 5 V eFuse on VOXL 2. Solid green means power good with no fault. Any flicker means the eFuse is toggling power-good or asserting a fault and recovering, so you are operating right at the edge of a trip. The system may look fine on the bench and then brown out when something shifts, such as a colder battery, a warmer ambient, or a transient load. Two questions before we can tell you which fault it is. Are your peripherals powered from the same upstream VBAT supply as VOXL 2, or from VOXL 2’s own 5 V output connectors? And can you scope VDCIN_5V at J4 pin 1 while the flicker is happening? What you are looking for is whether the rail is sagging or spiking. Sagging points at supply capacity: VOXL 2 expects 5 V ±5%, and the power module is set to 5.08 V no-load specifically to absorb cable drop. Adding load on the same supply eats that margin. Spiking above 5.6 V trips the eFuse overvoltage protection instead, which is a transient problem at the peripheral rather than a capacity problem. Also note our cable-connector power outputs are rated 1 A each and the system cannot supply 1 A on all connectors simultaneously: https://docs.modalai.com/voxl2-connectors/#power-inputoutput-important-note If it is droop and the total load is genuinely beyond one power module, separate the peripherals onto their own supply (using a second power module regulated from your VBAT) rather than sharing the VOXL 2 feed. If it is overvoltage, more supply capacity will not help.

Hi @김다연 GPIO 109 sync through M0155 Yes. GPIO 109 is on pin 26 of J6, J7 and J8, and M0155 passes it through to the sensor. Same sync signal M0173 uses. It is driven by voxl-fsync-mod. IR + EO on J6 and J7 Not automatic. Two things are required in software. The sensors must be running a sensor module built with sync input enabled (the fsin variants under /usr/share/modalai/chi-cdk/, selected by camera HW ID), and voxl-fsync-mod must be enabled and configured for the correct GPIO. Without the fsin sensor module, the sensor ignores the trigger and free-runs. The fsync period also sets the frame rate, which is the cleaner answer to your earlier 8.6 fps question: drive the rate from voxl-fsync-mod rather than adding a sensor mode to the driver.

Hi @davidtorresm, I dont believe ros2 foxy nor mpa-to-ros2 was included in the 1.8 release - please run the following to pull down the packages individually: wget http://voxl-packages.modalai.com/dists/qrb5165/dev/binary-arm64/voxl-mpa-to-ros2_0.1.0-202610080956_arm64.deb wget http://voxl-packages.modalai.com/dists/qrb5165/dev/binary-arm64/voxl-ros2-foxy_0.0.1-202511141235_arm64.deb Obvioulsy you will need internet to leverage the wget- but once those are pulled - feel free to just run sudo dpkg -i on both those packages followed by a voxl-configure-mpa-to-ros2 Zach

Thanks! I'll get back to you if I have any more questions.

On the Wi-Fi questions: The -M36 option ships with an Alfa Network AWUS036EACS (802.11ac AC600, dual band 2.4/5 GHz, Realtek chipset, made in Taiwan). It is listed on the Starling 2 Max datasheet. Yes, you can use a different USB adapter, as long as the VOXL 2 kernel has a driver for its chipset. You cannot install arbitrary vendor drivers without rebuilding kernel modules, so pick an adapter based on one of the Realtek chipsets we support: RTL8812AU or RTL8821CU / RTL8811CU. The adapters we have tested are listed on the VOXL 2 WiFi Setup page. If you find a Japan-certified (Giteki) adapter with one of those chipsets, it should work with voxl-wifi in both Station and SoftAP mode. If you cannot find a certified adapter with a supported chipset, another option is a USB-to-Ethernet adapter on VOXL 2 connected to a small Japan-certified Wi-Fi bridge or travel router on the drone. VOXL 2 only sees Ethernet, so there are no driver constraints. In SoftAP mode the default hostapd country code is US. For use in Japan, set country_code=JP in /data/misc/wifi/hostapd.conf after running voxl-wifi so the radio uses Japanese channel and power rules.

Thanks Tom and Eric, finally resolved this, it ended up being a power supply issue. The unit we used to typically run it on the bench seemingly browned out somewhere in the flashing procedure.

Files promised below voxl-mapper-packages.zip

There's some documentation here: https://docs.px4.io/main/en/flight_modes/offboard#ros-2-offboard-control. I would review that to make sure you are following the correct procedures.

Hi @john-keller , Glad to hear that it works As for the other issue, its possible that this is just a transient bus error somewhere that is causing the problem. If you encounter it again it would definitely be worth taking a closer look. Feel to open another post and tag me in it and I will take a look. Thanks!