Version 1.1 arrived and got assembled. All worked as expected and I can safely say that I am not expecting any major revisions for the schematic and electrical connections. There might be slight updates for component placement since I identified some things that could be done better.
Perhaps most importantly for version 1.1 is the fact that the EEPROM on the HAT works like a charm, meaning that the RPi on boot can identify that there is a HAT with specific needs present and assign quickly the right parameters on all peripherals and GPIOs. I am genuinely impressed by the cleanliness of the EEPROM solution for the HAT since it makes development and usage from end users so much easier.
Due to COVID-19 and some personal family priorities I had little progress on the software development for the past 2 months and things will be slow for the next month too. Since the hardware development is verified though I am inclined to send a board or two around to any takers that can commit on contributing for the software side of things. (@knro Jasem I am looking at you
Thanks for all your supportive messages and thanks for tagging along in this journey. Hopefully we will have something that all people can use soon!
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.
Losmandy G11, Gemini II, 10" f/3.8 Newt (Ostahowski Optics),
TV Paracorr-2, 2" Starlight FT, HSM20, Pegasus UPBv2,
ASI1600MM Pro, ASI174MM Mini, ZWO LRGB, EFW, & OAG,
StellarMate on RPi3 and/or Astroberry on RPi4
KStars 3.4.1 Build 2020-02-24T07:38:50Z on Win10 (updated 20200506)
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)
Last edit: 2 years 2 months ago by Jeff Wilson. Reason: More detail
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
- 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
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!