I can confirm the numbers in the Explaining Computers Video for the ICE Tower. The ambient temperature at which I tested the cooling using a 10 min stress test and maxing out all 4 CPUs was 5 degrees lower than in the video. The maximum CPU temp was 38 C. That's with the September 10 firmware update and running Ubuntu MATE.
This is a serious active cooling solution made for the warmer climates.
Atlas Pro AZ-EQ, ASI1600MM-Pro, ASI120MM-S, ES102ED, WO-Z61, Nikon D3300, ASI-EFW, ZWO LRGB,Ha,O3,S2 filter set
Here's a pic of my Indi/Kstars RPi box, which I mount on top of my scope:
On the left side of the box as pictured is an Raspberry Pi 3B+ with an Adafruit motor hat. On the right side on top is a little Anderson power pole power distribution box and below a little breadboard with a circuit for a dew heater. The my RPi has the following interfaces:
1x12V (or whatever-it's pass through) input (Anderson Powerpole) - For my setup, there is only one cable from the ground to my scope: 12V power. My goal is to minimize the number of cables running up my mount to my scope so I put the RPi on top of my mount. I power my mount from a separate power supply so there's no need to run power down from my RPi to the mount. I interface my RPi to the mount via bluetooth.
3x12V (pass through) outputs (Anderson Powerpoles) - One of these powers my SBIG ST-8300M camera and another powers my RPi via a 12V to 5V 3A converter. I'd like to figure out a way to power the RPi internal to the project box but haven't done that yet.
1x12V RCA jack driven by my little dew heater circuit.
1x3.5mm jack for a humidity/temp sensor - Used to calculate the dew point for my dew heater. Can also use ambient temp for focuser temp compensation.
1x3.5mm jack to read the OTA temp - Allows for closed loop temperature control of the dew heater. I've written a little python script for this.
4xUSB ports of the RPi for my imaging camera, guide camera, GPS, and a 64GB thumb drive for images
1xD-sub 9 connector for my focuser (driven by the Adafruit Motor Hat)
So I think you've got everything I've got and more except a separate temp sensor input for sensing the OTA temp and a focuser. Are there any left over GPIO pins so that an OTA temp sensor could be used? I think an Adafruit motor hat could be mounted on top of your board but it'd need to get 12V power somehow and the I2C address would need to be changed if your board is using I2C.
I had a similar idea, as follows:
A board with a microcontroller (Teensy 3.2) controlling two (at least) heaters and a motor focuser. Also on the board a LM2596 power converter to power the Pi and the microcontroller.
It measures the temperature right below the heaters (at the telescope) with thermistors so as to have an actual regulator. I intend to use a HDC1080 to measure ambient temperature and humidity.
I see two dew-controller modes: temperature tracking (with a few degrees offset to correct for discrepancies) or dew point tracking (again, with an offset).
For the focus motor, I think using the TMC2130 is great because the current can be regulated by SPI (forget about trimpots) and the possibility to use 'stallguard' as a sensorless homing feature. Then the focuser can start at the point it was used at the last time.
I would use the Teensy because it can have it's own firmware, and possibly also operate in a stand-alone fashion, using a cheap (or expensive, if that's your flavour) IR remote control for the focus and the heater controller.
Currently I have stripped the 'MyFocuserPro2' firmware and installed it on the teensy. It does communicate and everything so... great!
Only thing is, I've tried connect it directly to the UART of the Rpi 4 (enabling serial in raspi-config) but unfortunately it doesn't connect. Using a TTL-USB converter I can connect it.
A nice add-on would be to incorporate a RTC, or even use a GPS.
Edit: I've added a photo of what I'm working on at the moment.
Rpi4 connects with the mount via bluetooth. Only one cable goes to the telescope: 12V power.
And working on making a battery-pack counterweight.
Latest Stellarmate on Rpi 4B, 294mm-pro, EFW-8, CEM70
Last edit: 2 years 11 months ago by Bart. Reason: add photo
After a bit of waiting for production and shipping the first version of the PCB and the components arrived!
Now I can start the assembly and hopefully start testing really soon. I will keep this thread updated with details.
Stellarmate OS on Raspberry pi4b
Skywatcher EQ8 pro, on steel pier
Takahashi FSQ85, FS60cb & Meade 8” SCT (de-forked)
Starlight Xpress SXVR H18, SXVR M25c, Lodestar x2 Guide Camera
Pegasus Ultimate Hub V2 for all USB & Power
Pegasus focus motors on all scopes
I am not wishing to hijack here. Full respect and consideration to ppapadeas.
Gonzo the great, You should contact the maker and suggest a combined USB 3 switcher and the raspi power button all on a board / hat to fit the raspi. Would have applications beyond astro stuff.
This is very interesting, here's a feature that would be great to have on this amazing board: switchable USB's ports.
I personally use www.yepkit.com/products/ykush and it's excellent.
As a general note adding a USB switch on the existing board would be not really feasible since we dont have a way to do that through the RPi hat-pinout. (and adding an extra cable to a USB port kinda defeats the purpose of a "hat")