What is that Arduino doing?

Arduino Uno

Because I want to control my set-up from inside my house I knew I want to invent a way of monitoring what it going on at the mount. My electrical engineering background caused me to initially focus on monitoring the power supply. I started reading up on microcomputers and I became fascinated by what I could do with an Arduino so I started off writing a program that interfaced to an Arduino Uno. Arduinos are microcomputers that are designed to interface with a slew of different sensors. They only have 32Kb of memory but they can accomplish a lot.

5 Amp DC Current sensor

I have the Arduino connected to a DC current sensor and a voltage sensor which monitor how much power my Celestron 5 Amp 12 Volt supply is delivering.

DHT Digital Air Temperature and Humidity Sensor

I also have the Arduino tied to a TDS18B20 digital temperature sensor bonded to the Celestron power supply so that I can also know how hot it’s getting. I also have the Arduino tied to a DHT digital air temperature and humidity sensor so that I can see what the ambient air temperature and humidity are at the mount.

Raindrop sensor

I also have the Arduino connected to a rain detector which has only triggered once. The detector is a plate that is affixed to the outside of the box. It has wiring etched on it’s surface which will detect if a rain drop lands on it’s surface. One very humid night this sensor scared me and I quickly went outside to see what’s up. It wasn’t raining but the set-up was drenched in dew. Some of the electrical cables were dragging across this sensor and the dew triggered it.

MLX90614 Infrared Temperature Sensor It has a +/- 5 degree field of view.

In 2019 I added a MLX90614 Infrared Temperature sensor which I have mounted on my guidescope and have it pointed to the same field of view as my telescope. This sensor tells me how cold the air is in the upper atmosphere which is a great indicator of how transparent the skies are. Many cloud sensors are based upon this device.

QMC8553L digital Compass Sensor

Late in 2020 I added a QMC8553L digital compass sensor. I have not had a chance to test this sensor outside. I hope I can use it to determine the compass direction of my mount so that polar alignment is a little bit quicker.

I also have an Arduino Nano that is mounted on one of the tripod legs. This Arduino is connect to a sensor that I designed. It functions as a solid state wind speed and direction sensor. There are no moving parts and it can detect the wind’s strength and in what direction it is blowing from. I have searched the web and I didn’t find anyone who has invented a similar sensor. I also have a BMP180 digital air pressure sensor connected to this Arduino Nano.

BMP180 Digital Air Pressure Sensor
MPU6050 Digital 3 axis accelerometer

I also have a MPU6050 3 axis digital accelerometer which I may decided to make into a stand-along digital bubble level. I use a bubble level to level the tripod before I attach the mount. The bubble level works fine. My only complaint is that I can’t see the bubble level when I am adjusting the length of the tripod legs. I hope to have this device located in the same spot as my bubble level. I will have the sensor tethered to a display that sits on the ground so that I can see the change in level as I adjust the legs. I have had too many nights where align/calibration or polar alignment took far too long or was not possible so I firmly believe that consistency is imperative. All of these devices cost less than $15 each so I’m not breaking the bank when I add them to my system.