Depends a bit on how much activity you expect and how long insects stay around on average, but similar to what has been suggested before, I'd consider not using a motion trigger, but instead taking pictures in regular interval.

Wow, what a great project.

This is a great project! Some comments:
RaspberryPI though accessible is not the best fit for video pipelines and AI workloads or off grid deployments:
- it lacks onboard ISP which means either software implemented ISP, distorted data or on camera non energy optimized ISP.
- it lacks any power management techniques, low power modes, etc.
- it runs from SDCard using the same one for OS, swap and data, any corruption can lead to full loss.
- it runs any AI/ML workload on CPU which is extremely non efficient and any addon accelerators such as Hailo8 add a lot to power consumption and heat dissipation representing more challenges.

The advantages are of course plenty of documentation, community and all kind of makers addons, hats, etc.

For something more realistic, real life suitable I would suggest using something based on SoC with integrated NPU such as Hailo 15, Renesas RZ/V, Synaptics SL1680, MediaTek Genio or even the I.MX8M Plus for very light AI/ML workload. All of these have variety of SBCs, kits or even standalone smart camera oriented designs available from different vendors.

@hikinghack that's a complete update!

A lot of compassion regarding the budget situation, especially knowing how great @briannaljohns is.

It’s great to see a clear plan for the hardware development! I hope you'll have nice outcomes from it! 

On the microcontroller approach for power gating the Pi — this is a well-proven pattern and worth doing even if the idle power is already low, because it also gives you a hardware watchdog for free.

The typical architecture is a small ultra-low-power MCU (STM32L0, SAMD21, or even an ATtiny) that stays awake in stop mode drawing a few microamps, handles the RTC wake-up schedule, and drives a P-channel MOSFET or load switch to cut power to the Pi entirely. When the Pi is done with its task, it signals the MCU via a GPIO line and the MCU cuts power and goes back to sleep. The key advantage over software sleep is that even a hung Pi gets cut off at the next scheduled cycle — no manual intervention needed in the field.

For the Mothbox use case where the Pi might sit idle for weeks, even 10mA idle current adds up to about 168mAh per week — enough to matter for a solar-charged system during a cloudy period. A properly gated system can get standby down to under 1mA including the MCU and RTC.

One practical note on the integrated PCB direction — if you're planning to integrate the MCU on the same board as the Pi interface, make sure to include a dedicated programming header (SWD for STM32, UPDI for modern ATtiny) so the MCU firmware can be updated in the field without disassembly. It's a small thing that saves a lot of frustration during deployment.

Happy to share more detail on the power switching circuit if useful.

@Hubertszcz maybe you have advice: "Minimum resolution or lens characteristics that are sufficient for guild-level classification" 

i don't really know what guild-level means.

@domvonmatter - do you have a photo or drawing example of what a carrion station would look like on the forest floor? like will the camera be on the ground? Will it be above the ground but looking down?

how big of an area does it need to image?

what data do you need to get out? Like behavior that might need full motion video but maybe lower visual resolution? or just identification that might need lower temporal resolution, but higher visual resolution

• DOI:
• 10.1038/s41598-025-31811-7

There aren’t that many close-focus trail cameras.  The only current model I’m aware of is the GardePro E8PCF.  It is fixed focus at 200mm (no zoom).  I have not used this camera, but know others who have.  It has a timelapse feature. One thing to check before buying is that the timelapse feature works at night.  The GP website has a picture that suggests this true, but I know (for example) that in Browning camera timelapse does not work at night.

[There are other options.  You can attach lenses from reading glasses to a standard focus trail camera to convert it to close focus.  I have developed firmware hacks for older Browning SpecOps and ReconForce cameras that allows the timelapse to work around the clock.  Alas, these hacks don’t work on the latest HP5-Ultra models, and retrofitting optics on a pile of cameras is probably not how you want to spend your time. I'd try the GP]

Have your findings/recommendations changed since 2023 on possible RPi cameras? 

Has there been experience trying to use the different cameras (particularly the Hawkeye) in hot climates? The Pi Camera 3 lasts only a few months here before the lens cover/filter becomes all milky.

And is it correct that the IMX519 and Hawkeye work for our purposes without additional lenses?