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?
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.
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.
When I built my dew heater control box quite a few years ago I used DS18B20 on each strap to allow me to feed back and control the PWM to teh strap itself. This needed something different to the phono style connectors so I used 4 pin DIN connectors at the time.
I am really interested in this project - I think I would use off-board connectors to allow the above implementation plus that would allow for better weather proofed solution (though not watertight, but if I can avoid condensation getting in to the enclosure that would be good.
Looking forward to see how it progresses... and where I can help if possible.
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.
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 am also working on to get a price for machine populated boards.
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.
AstroEQ uses the DRV8834 driver in Tom Carpenter’s device. I am using it now to operate my scope. Most of my time with it requires power to move motors. The potentiometer needs a VOM to set the amps. My NEMA 17 motors are cool to the touch when the amps are < 2.0 rating,
On Tom’s AstroEQ, the particulars data needed are number of teeth of the RA and DEC scope, the gear ratio of the motors, and any ST4 drivers. The software calculates the default slew rate.
I totally agree to keep the housing dimensions as they are. If you're talking about motor connector, RJ11/12 definitely is the way to go. I was thinking of a JST connector to optionally connect the motor driver module, but if you're planning to integrate it and provide directly a motor connector it's better.
Overcurrent protected smart MOSFETs would be perfect, provided we have enough pin to interface them.
I don't like 3,5mm jack connectors, seems to me they are not reliable and time-resistant; but it's only me and lacking a better alternative they're ok.