# Ardusub not downloading **URL:** \ **Category:** ArduSub\ **Created:** [September 29, 2025, 4:34pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694 "2025-09-29T16:34:49Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [September 29, 2025, 4:34pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/1 "2025-09-29T16:34:49Z")
![image](https://us1.discourse-cdn.com/flex019/uploads/bluerobotics/original/3X/1/e/1e2189f1be88e0d2d4013e6b8f24d826b6133472.png) Hello, ive tried downloading ardusub several times and I keep getting this error. pls help. Thanks! ---
**Author:** ![tony-white](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/tony-white/32/18385_2.png) [@tony-white](https://discuss.bluerobotics.com/u/tony-white)\ **Post date:** [September 29, 2025, 5:02pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/2 "2025-09-29T17:02:06Z")
Hi @n3804 - Some more context would be helpful. The error message seems to indicate that the board does not have sufficient memory to take the upgrade - what flight controller are you trying to flash? With what version of QGC? ---
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [September 29, 2025, 5:19pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/4 "2025-09-29T17:19:41Z")
> [@n3804](#): > > Hello, im using 3DR Pixhawk and im using the latest version of qgc. Hello, im using 3DR Pixhawk and im using the latest version of qgc. ---
**Author:** ![tony-white](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/tony-white/32/18385_2.png) [@tony-white](https://discuss.bluerobotics.com/u/tony-white)\ **Post date:** [September 29, 2025, 5:32pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/5 "2025-09-29T17:32:24Z")
Hi @n3804 - It may not solve the issue, but we recommend [QGC version 4.2.8,](https://github.com/mavlink/qgroundcontrol/releases/tag/v4.2.8) as that’s the last version Blue Robotics thoroughly tested…. If the error remains the same, I’d suspect the pixhawk hardware itself is damaged, or you’re trying to flash the wrong version for that hardware… ---
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [September 29, 2025, 5:40pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/6 "2025-09-29T17:40:43Z")
![image](https://us1.discourse-cdn.com/flex019/uploads/bluerobotics/original/3X/f/4/f4ab1653e14422cd56932233a7ee786b784ba6f6.png) flashing px4 works just fine. But when i try flashing ardusub it gives me the same error. these are the options I get. ---
**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\ **Post date:** [September 29, 2025, 6:08pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/7 "2025-09-29T18:08:01Z")
Hi @n3804, From your QGroundControl error message, it looks like your flight controller board only has ~1MB of flash, so it will likely need to use one of the Pixhawk1-1M firmware builds. I’m not entirely sure which features get removed to fit within that, but I’d suggest trying the default one, and if you run into something missing that you need then you can either try [adding it to a semi-custom (online) build](https://custom.ardupilot.org/add_build), or setting up the build system locally for testing fully custom builds (and adjusting the build flags as relevant). > [@n3804](#): > > flashing px4 works just fine. PX4 is a completely different firmware, so while the flashing _process_ is the same, it can’t be expected to use comparable amounts of flash, or have directly equivalent features. ---
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [September 29, 2025, 6:09pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/8 "2025-09-29T18:09:13Z")
Ive flashed Pixhawk1-1M for arducopter and rover both work perfectly, but when I do the same for ardusub it doesnt seem to work ---
**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\ **Post date:** [September 29, 2025, 6:14pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/9 "2025-09-29T18:14:35Z")
> [@n3804](#): > > when I do the same for ardusub it doesnt seem to work In what sense? The autopilot doesn’t start up at all / connect to the control station software, or there are missing features? ---
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [September 29, 2025, 6:17pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/10 "2025-09-29T18:17:16Z")
it doesnt connect to mission planner or qgc. ---
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [September 29, 2025, 6:18pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/11 "2025-09-29T18:18:03Z")
![image](https://us1.discourse-cdn.com/flex019/uploads/bluerobotics/original/3X/3/c/3c6ee66202f8e83a5c7889b3cd546856e02802ca.png) ---
**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\ **Post date:** [September 29, 2025, 6:35pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/12 "2025-09-29T18:35:13Z")
I’ll try to raise this with @williangalvani, as the lead ArduSub maintainer. In principle the 1M firmware builds _should_ work, but I’m not sure we’ve tested them much, if at all. ---
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [September 29, 2025, 8:20pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/13 "2025-09-29T20:20:41Z")
Please do let me know of any updates as I need it up and running ASAP. thank you ! ---
**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\ **Post date:** [September 30, 2025, 1:40pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/14 "2025-09-30T13:40:52Z")
I’ve just tried flashing a normal Pixhawk with the 1M firmware and found that there does seem to be a loading issue with the Sub-4.5 releases. I did try making a semi-custom build with some adjusted build flags to what I considered most relevant, but it failed to build. We’ll try to look into why those aren’t working, but I’m not sure how soon we’ll be able to have a working release. If it’s relevant, [4.1.2](https://firmware.ardupilot.org/Sub/stable-4.1.2/Pixhawk1-1M/) seems to load as expected, and so does the latest dev release, so if you urgently need a working firmware then you can try either of those. My earlier point about the -1M builds being less tested stands though, so you may encounter some missing features depending on what you’re trying to do / connect. ---
**Author:** ![n3804](https://avatars.discourse-cdn.com/v4/letter/n/7cd45c/32.png) [@n3804](https://discuss.bluerobotics.com/u/n3804)\ **Post date:** [October 10, 2025, 10:28am UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/15 "2025-10-10T10:28:37Z")
Hello, are there any updates on the newer releases? also would it work on blueOS? ---
**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\ **Post date:** [October 10, 2025, 10:00pm UTC](https://discuss.bluerobotics.com/t/ardusub-not-downloading/21694/16 "2025-10-10T22:00:42Z")
> [@n3804](#): > > are there any updates on the newer releases? No - we haven’t yet had a chance to investigate why the Pixhawk1-1M builds aren’t working in the 4.5 branch, or how they got broken. I also don’t expect this will be prioritised particularly soon, given the builds work from the old stable (4.1), and also the development branch. > [@n3804](#): > > would it work on blueOS? I’m not sure what you’re asking here. If a valid firmware is loaded to your board, then it should work with BlueOS. If it’s relevant, BlueOS is currently not well set up to flash firmware onto less commonly used boards, but there is [ongoing work](https://github.com/bluerobotics/BlueOS/pull/3025) to improve that kind of support.