Astrohat - An open hardware RPi Hat for astronomy equipment

98/5000
The project seems fantastic to me, I would like to have a card with the 4 12V outputs to try.

Eagerly awaiting any progress, willing to pay to give it a try, as far as hardware goes- I can easily fill up all the outputs. Is there still room on the GPIO for a couple I2C sensors for temp/RH and the such? You're going to give Pegasus power packs a run for their money, I suppose. I'd buy one of these over another UPBv2, no doubt.

Perhaps the biggest spec for me on this board is the 12V input to the hat- it powers the Pi, correct? Heck. YES. Much needed. Who has time for 5V when you're mobile? Too much struggle, imo.

Thanks for tackling this- it's going to be very useful. Hope you're doing well during lockdown.

Stay up,
Jacob

I thought about Raspberry 4 fan, how are you going to manage it ?

Gérard

I was considering that too. I have seen some PoE designs that have a hole through the center of the PCB.
Anyhow, I was thinking a side-mounted or angled fan might be possible. In my experiments, the underside of the Pi4 could use more heat dissipation.
www.prusaprinters.org/prints/30600-raspb...an-case-supports-rtc
(See the photos with the thermal filament)

Thanks,

I was wondering the way to put the Raspi 4 onto my telescope, Noctua is a good one to avoid vibrations ... Have any people resolved vibrations to the telescope with fan ?

Gerard wrote: Thanks,

I was wondering the way to put the Raspi 4 onto my telescope, Noctua is a good one to avoid vibrations ... Have any people resolved vibrations to the telescope with fan ?

I don’t notice any vibrations with the fan running at 5V. The fan came with dampening pegs.

Hello all, more updates on my side!

Since the last update, I've been hardware verifying all possible operations on AstroHAT and trying to start on the software side of things.
In order to expedite the process of software development and testing, I decided to manufacture 10 AstroHATs v1.1 and make them available for people that are willing to help me out on software development.

What works right now:
- Supply all system power from single 12+ V input
- Power RPi4 with appropriate protections (as specified on HAT documentation)
- 4x 12V channels with on/off via GPIO
- 2x 12V dew heater channels with on/off via GPIO
- Serial breakout for GPS
- I2C breakout for temp/humidity sensor

What needs development:
- INDI driver
- Interface with Power Switch ICs to measure consumption and display errors
- Interface with SPI potentiometer chip to allow tuning of variable voltage (right now it is unset, thus random)
- Interface with Power Switch ICs for dew heaters to allow less duty cycles

Later on:
- Case design
- Sourcing and testing different parts and external things (temp sensor and GPS)

If you think you can help please reach out to me with your details to figure our a way to get you an astroHAT and get started!
Skills needed: Indi driver knowledge, devicetree experience, familiarity with electronics, debugging and related tools and equipment. Any of those would be helpful at this point

Disclaimer:
This is a free-time side project for me. I plan to keep working on it on my free time to support further development and see it through. No promises for time and commitment around it though!
All AstroHAT development (software and hardware) is and will remain open source. I plan to make some kits for people that are interested more widely once we have everything working and tested sufficiently.
The bare cost of PCB+components right now is approximately ~70 USD (remember we opted in for automotive grade electronics.. some are costly!) You can find the full BOM in the repo here gitlab.com/pierros/astrohat
If you want to help with software development and get an early beta board, you could help with that cost too. If not, just helping with software is still totally fine!

That is a great project! I am considering building a hat with at least 4 12V outputs for my gear. I though that would be something that's available commercially, but apparently not.

jnowat wrote: Perhaps the biggest spec for me on this board is the 12V input to the hat- it powers the Pi, correct? Heck. YES. Much needed. Who has time for 5V when you're mobile? Too much struggle, imo.

That could be easily solved with a 12V USB hub. That's what I use to have a single 12V line as the only cable running up the mount.

freiform wrote: That is a great project! I am considering building a hat with at least 4 12V outputs for my gear. I though that would be something that's available commercially, but apparently not.

jnowat wrote: Perhaps the biggest spec for me on this board is the 12V input to the hat- it powers the Pi, correct? Heck. YES. Much needed. Who has time for 5V when you're mobile? Too much struggle, imo.

That could be easily solved with a 12V USB hub. That's what I use to have a single 12V line as the only cable running up the mount.

No need for such complexity! AstroHAT directly powers the RPi4 appropriately and with the right protections in place.

ppapadeas wrote: No need for such complexity! AstroHAT directly powers the RPi4 appropriately and with the right protections in place.

Of course, but I'd first have to build one and I am not the biggest fan of SMD soldering.

Also, I need the addtional USB ports anyway...

Guys, is there any new update on the Astrohat?

thanks,

V