FLIR DUO R Drone thermal camera teardown by Fraser

[Fraser]

I purchased a faulty FLIR DUO R thermal camera today.

For those unaware of this camera, the FLIR DUO is a combined visible and thermal imaging camera that was designed for drone use. That is not to say tat it cannot be used in other applications. The visible light camera is an HD 1080p module and the thermal camera is a Lepton3 160 x 120 module. There are two version of the DUO, non-radiometric 'DUO' and radiometric 'DUO-R'. Both cameras are equipped with MSX.

The unit that I purchased is the radiometric 'R' version that can output both analogue and digital video. The camera can also link to a Bluetooth equipped mobile phone. The camera may also be controlled via four common RC PWM signals !

The history on my unit is that it is brand new but failed to respond to power after three test starts. The retail company that was selling them wrote it off ! Why they did not get it replaced by FLIR I do not know. I am told that the camera was not abused and just stopped working. Likely infant mortality.

I purchased the camera for several reasons, including my curiosity in the design and the potential to use the camera on a mobile platform of some sort. The fact that the unit is also the Radiometric video version is also interesting to me.

Upon collecting the camera I could see that it was indeed 'mint'. I looked at the construction of the casing but could see no obvious fasteners and the case is not glued together. I used my Faxitron X-Ray machine to image the DUO-R and locate the case fasteners. They were present, and hidden under the very fragile front panel label. After some very careful heating and lifting with a number of razor blades, I revealed the two hidden screws. The story does not end there though. Both screws were thread locked. One came out OK, but the other sheared off whilst being carefully unscrewed  The two screws are M1.6 x 18mm, so quite fragile when thread locked.

I shall investigate the failure to start fault as and when I have time. Hopefully very soon.

OK, to the pictures

[Fraser]

X-Ray images used to find the hidden screws

[Fraser]

Teardown pictures begin......

[Fraser]

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[Fraser]

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[Fraser]

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[Fraser]

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[Fraser]

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[Fraser]

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Rebuilding the Lepton3 assembly ready for re-installation.

Note the temperature sensor mounted in front of the Lepton module.

Fraser

[Fraser]

The sharp eyed will have noticed a speck of debris sitting on the visible light camera imaging sensor. I am uncertain whether this was present from original manufacture, or whether it fell on the sensor during disassembly. I carefully removed the PCB from the rear of the Lens block so no debris should have fallen on the sensor. I will remove the debris using dry compressed air. 

Fraser

[Fraser]

Initial comment on construction........

I am use to working on Industrial thermal cameras so when I first looked inside a F1G2 dongle it was a bit of a shock 

The DUO R is no different.

The rear case is an alloy casting of decent quality and a heat transfer plate is attached to its interior to draw thermal energy away from the rear most large IC (unidentified at the moment) A nice touch and far better than the stack of heat transfer pads that I have seen on some cheap kit.

The front casing is made from ABS plastic that has been coated in conductive paint on its interior. The case halves are held together using two M1.6 x 18mm screws. I find this a poor choice of case fastening as four screws should be located at the corners for a secure case closure. The case is unsealed and NOT water resistant ! Remember, this is for use on a DRONE 

The choice of connectors on the camera mimic those of the GoPro Hero and this is to enable compatibility with GoPro Hero Drone mounts and cables. There is no weather sealing around the connectors.

The PCB's used in the DUO camera appear to be of decent quality at first glance. The PCB's and other internal parts are secured in place using very small screws that bite into plastic mount points rather than brass inserts. Some plastic mounting points are already split, as is common with such a design.

The visible light camera uses a standard 'S' mount lens that is marked as being for 3MP sensors. The Lepton3 lens is the standard wide angle version with an FFC shutter mounted in front of it. A temperature sensor is mounted in front of the FFC shutter. The design of the Lepton mounting assembly appears over complicated and somewhat messy. Tiny screws bite into plain plastic mounts and the whole Lepton mount plastics look pretty ugly in both design and implementation. A strange Lepton assembly securing screw is present that tightens against a sprung plastic clip. The screw was loose on my unit and glue had been used to secure the assembly adjacent to the screws contact point with the clip.

The DUO camera design does NOT incorporate ANY shock mounting techniques to protect the PCB's, components or imaging sensors. This thing is suppose to hang under a drone, yet I see no evidence that it is ruggedized in any way at all. A FLIR basic design FAIL in my humble opinion. I suspect this camera would not take kindly to uncontrolled descents or flying through a rain shower.

Enough from me for now

Fraser

[frenky]

Very nice teardown. I hope you will be able to fix it.