EEVblog #1207 - ARM Dev Boards Falling From The Sky!

Hackable STM32 based ARM RF dev boards are literally falling from the sky!
A teardown of two weather balloon Vaisala radiosondes, the RS41 and RS92.

#STM32 #RadioSonde #Teardown

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[bazjo]

I have documented my progress in reverse engineering the RS41 in GitHub. Youtube is a bit picky in me posting links here, but searching GitHub for RS41 will bring you there.
RS41_Hardware - hardware reverse engineering with mostly complete theory of operation
RS41_Decoding - radio transmission format reversing with mostly complete description of the transmission protocol

[craigbyrne]

Sadly disposable, the ones from the Michigan (usa) fall from the sky with postage and an envelop to send back to the weather station for reuse.

[TiSapph]

The water packs might just be to keep the batteries above 0°C. They can't get below that without freezing the water entirely first, which takes a huge amount of energy (*to be conducted out)

[astrohardy]

Beautiful video. Some remarks on the old RS92. Labelling: "D"=AA Batteries, "A"=AA Batteries, suitable for automatic launchers; "L"=Lithium battery pack; "W"=Water batteries. The A model has an on-off switch that would be punched in by the launch robotor.
The RS92 did not process GPS coordinates onboard; this was down by a computer at the ground station.

The realistic operating time with the RS41 and for the RS92 A and D models are about 10 hours.

[erikjgreen]

I choose to believe the liquid is vodka, and it's for whomever finds the sonde :)

[radiosonde.online]

Dave, the RS41 sends full 10 hours. The 240 minutes are a very cautious statement in the data sheet.

[ventusprime]

i wish where i live it would ARM Dev Boards Falling From The Sky!

[geepchaser]

Dave
the 2 humidity sensors allows for 1 sensor to be heated and remove moisture while the other sensor is in use. they are switched back and forth. D= alkaline dry-cell battery L= lithium battery A= dry-cell for autosonde all 3 radiosondes measure pressure. temperature. and humidity .

[benjamilindqvist]

Jesus! A product of Finland! The Head office of the company is right next to my house :D

[gamerpaddy]

went on a RS41 hunt recently.
first two, someone else was faster. third one.. on a rooftop, fourth one fell into a river. fifth lost in the woods, sixth one i finally retrieved.
it had a expansion port with a weird module fitted i couldnt informations about, looked like a barometric pressure sensor (1cm diameter metal can on ceramic substrate, hole in the bottom, qr code ontop).

[mikeselectricstuff]

For a radiosonde, they don't need to fully process the GPS data into a position as the sonde doesn't need to know where it is - they can send raw or intermediate data to be processed at the receiving end, saving on battery power and cost.

[TehMG]

60mW may not sound like a lot, but with unobstructed line-of-sight, it can go a long ways (these often reach over 100, 000 feet altitude). I've been able to receive and decode the signal from these at distances in excess of 300km!

[picwiz]

Hi, according to what I have read, these batteries (AA size)are not the "right" batteries used in a sonde so the organization must insert that sort of ballast (water containers)
because the sonde must have the same weight compared to the others.
The "right" batteries are ... water batteries: I mean they are activated by adding water a little before the launch (probably they are a sort of lead-acid batteries and this hypothesis justifies the considerable weight).
A battery of that type can be stored (dry) even for years without problems.
They use standard alcaline batteries pack in case the operator... "forgets" to prepare it or if for different reasons they have not the "right" batteries

[molak]

Those water containers will clamp the temperature to 0C until they froze completely.

[JerryDodge]

"It's up-side-down, so all the electrons have already all fallen out..." And this is why I watch your channel.

[NfxNet]

I worked for u-Nav! I was an applications engineer, and I designed most of the eval and demo boards. Good times. u-Nav was bought by Atheros, then they were bought by Qualcomm. Three employers, same desk. I wasn't aware that anybody was using our front end without its matching baseband processor. But it makes sense that Vaisala would have used them without me ever hearing about it here in the USA, since they naturally would have interacted with our Finland office, where most of our software development was done.

[bazjo]

I have documented my progress in reverse engineering the rs41 on github:

[rfengr]

It’s funny to see the same topology “chip” antennas for GPS and WiFi. They are nothing but a capacitive divider to resonate the inductive notch in the PCB. They will sell you one for several $ when it’s equivalent to two SMT capacitors.

[travis]

Made to be disposable, their probably not concerned for anyone reverse engineering these especially with packaging that's not designed to protect the insides, just keep it functioning in the extreme cold. Those packs are definitely for warming, the upper atmosphere can get so cold it will not only freeze batteries but it can freeze i/c's too. Looks to do the basic function of collecting data and sending it out and that's about it.

[jamesheller]

And good thing about this is that you can just wiggle wiggle yeah..