Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

gilesco wrote: I would worry if it tries to emulate the PPB Advance to a tee.

I do not really understand what you mean when you say "worry". This board is a HAT or Shield for Raspberry, without it, it is not able to operate. PPB is let say a stand-alone product.

The moonlite focuser interface, for example, is something that I was hopeful to not have - no use for me, can be done via the Pi.

Regarding the focuser, the target (basically the recommendation was) is to have a stepper output, means the currently existing Astroberry focuser Indi driver would be possible to use with this board.
So I am working on integrating a DRV8834 driver on board.

I guess the price point would be the key

I am also working on to get a price for machine populated boards.

tied with an Argon One M.2 case... or can take on the PPB Advance, with Pi4 integrated, with a type of Argon One M.2 thepihut.com/products/argon-one-m-2-raspberry-pi-4-case

The current mechanical design is based on to use standard aluminum extruded housings, this Argon One type would require a complete redesign, and the pre-cuted connectors (HDMI, USB-C ...) are useless for that design.

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

Hi Magnus,

mlarsson wrote: i.ebayimg.com/images/g/ItUAAOSw55FcVvQ9/s-l1600.jpg

Exactly, that is what I have also found in the catalog.
I will order a couple of, to study them.


Tibor

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

picciux wrote: ATM 4 GPIO left unused. If GPS reset is not used and 3Dfix led can be sacrificed, we could have 6 gpios to let the unit control focuser stepper motors using already available Radeck Astroberry Focuser indi driver. On the power shield side, only a JST like connector to link one of those mini stepper controller modules is needed.

Yes, I am thinking about how to implement it, I do not really want to have the housing bigger, and currently, the front and back plates are full of connectors, based on my testing during the last week, it seems that I have to remove the onboard BME280, because the RPi temperature is influencing it quite much, so if I do so I would have space for another connector.
Do you think a JST 2,54mm pitch connector would be okay for that? I think an RJ11/12 is more common, or?

MCP3202 can be replaced with 3208 and populating 1 INA328 and OP-AMP per channel we'll have amps readings per-device instead of total. Maybe it's an overkill, don't know.

When I have started that design I have also thought about single-channel current measurement, and I am open to modifying it, with a smart MOSFET so I can also remove the fuses because the smart MOSFETs are overcurrent protected. This could help the place a stepper driver on the board.

the OneWire pin can be used to chain one or two DS18B20 temperature sensors to monitor stuff that has to be kept dew-free: since ambient temperature and relative humidity are already available, we can calculate dew point temperature and automatically regulate heaters at minimum power needed to keep dew away. Obviously lacking (or not working) the sensor, the channel works in manual power mode. I've already done it with Arduino, code is simple and I can contribute it.[/quote]
As I mentioned previously the onboard BME280 cannot be isolated 100% from the RPi, so I am planning to remove it, and maybe add two 3,5mm jack connectors, one for I2C sensors, like BME280, and one for one-wire sensors. Let's see how all these fits on the board.

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

Deesk06 wrote: I like the original design OP has. Powerpole connectors are great but seems like it would take up more real estate on the hub itself. Those connections are somewhat wide. The 2.1mm connection seems better IMO with the reverse polarity protection

If I understood the others, they were recommending the PowerPole instead of the XT60 input power connector. I agree with you the normal DC jack (2.1mm or 2.5mm) is better (more common) to use for the outputs.
As far as I understood the PowerPole has also a kind of polarity.

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

jabian wrote: They are very common in ham radio. There are racks for power distribution, very popular, some with fuses. Some models can stand very high currents.

Yes, I have also found on Wikipedia that radio amateurs using it as well.

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

mlarsson wrote: Hi!
And I'm talking about these:
andersonconnect.com.au/store/index.php?m..._info&products_id=93


I have also checked these, but I was mainly focused on which can be used on PCB side, the only disadvantage is the population on the board could be a little bit difficult compared to XT60 which is a solid block together with pins.
I will order a couple of samples to see how it looks.

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

mlarsson wrote: Why not an Anderson Powerpole connector for 12A?

To be honest, this type of connector was not known by me till today, but I like it, I can imagine replacing the XT60 with a 45A type of Powerpole.
The only question is this Powerpole connector more common in astrophotography? Because if it is, then makes sense to change it.
(XT60 is I think absolutely not common, but in every RC shop it is available)

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

stevenball wrote: The 12v power is connector, is that a common style connector with leads that can run from a battery pack with say a car style cigarette lighter socket on ?

The input connector is an XT60 type, such a connector is needed because the board can handle 15A, and a usual DC jack (2,5mm/5,5mm) can carry only 5A.
I have quickly checked on Amazon and there is XT60 to cigarette lighter cable.

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

Psamathe wrote: 1. Add an external Wi-Fi antenna (signal strength seems an issue for my RPi inside a case

That is a good idea, but unfortunately, currently, the Raspberry design has no option to connect an external antenna, maybe to hack the RPi would be possible, but one of the main points was during the development is to use the RPi as is, then everybody can attach it.

2. Fan location/position: dew falls downwards so ensure the airflow is drawing in from underside and expelled ideally through a side?

That is a really good point, currently, the GPS and the fan are on the same side, and to use the internal GPS antenna the top of the box should point upwards.

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Tibor Kiss replied to the topic 'Power Shield for Astroberry' in the forum. 3 years ago

gilesco wrote: Yes, don't get me wrong, I'm interested with this "as-is", but as we're still in the stages of design, just thought that some suggestions might still be worthwhile. Even if it is space internally to house a 2.5" SSD SATA, and a hole (perhaps with a blanking plate) big enough to loop a USB cable back internally.


So the idea is really good, first I will do some small updates on the current design to prepare it for assembly with an SMD machine.
SSD, M2, or such drive would require a bigger design change, but this point is on the improvement list, thanks for the feedback!

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