The drivers are probably the most important piece to the puzzle. Once the driver is running for a particular device, then any program that speaks Alpaca can utilize that devices. This also includes a web browser. However you can not send action commands to the driver from a web browser. You can read all of the status.

The AlpacaPi drivers run on Linux and were designed with the Raspberry-Pi in mind. They will run on most any flavor of linux.

AlpacaPi drivers currently support the following devices.

• Cameras
  • ATIK cameras
  • FLIR grasshopper series cameras
  • QHY cameras
  • QSI cameras
  • SONY A7 R IV DLSR camera
  • TOUPTECH cameras
  • ZWO cameras

• Domes
  • Raspberry Pi w/Motor control board for dome
  • Raspberry Pi w/Motor control board for Roll Off Roof

• Filter Wheels
  • Atik filter-wheel
  • QHY filter-wheel
  • ZWO filter-wheel

• Focusers
  • Moonlite NiteCrawler
  • Moonlite High Speed Stepper

• Observing Conditions
  • Raspberry Pi with sensors

• Rotator
  • Moonlite NiteCrawler

• Switches
  • Raspberry Pi with a 8 Relay board
  • Raspberry Pi with a 4 Relay board
  • Raspberry Pi with a WaveShare 3 Relay board

• Telescope (Mounts)
  • Talks LX200 via TCP/IP to tsc mount controller
  • Rigel - Custom driver for Jim H.
  • Raspberry Pi with Servo controller
  • Skywatch

Client and server operation

For example, if you want to utilize the 4 port switch (described below), follows these steps:

• On the driver machine
  1. make piswitch4
  2. ./piswitch4
• On the client machine (can be the same as the driver machine)
  1. make switch or make switchcv4
  2. ./switch

Dome	Focuser	Switch

Dome driver

• Dome with rotation and single shutter
  
  • This option uses DC motor controllers

• Roll Off Roof with roof acting as the shutter
  
  • Version using relays for driving motors
  • Version using DC motor controllers

• The watchdog timeout occurs if no commands have been received for the specified time. (default is 5 minutes). If SkyTravel is being used, it queries the dome driver every few seconds for status thus resetting the timeout. The Dome watchdog timer controls the dome shutter. If the timeout occurs, the shutter will close.

• The Dome movement timeout occurs if no MOVE command is received in the specified time (default is 2 hours). The Dome movement timer controls the dome position. If the timeout occurs, the dome will be sent back to the PARK position

Remote Shutter

The SHUTTER devices is a non-standard Alpaca device. It will not be recognized by other Alpaca clients. It responds to the same door/shutter commands as the DOME device.

The AlpacaPi dome driver uses DC motors and a PWM controlled DC power board that handles reversing and power output. It also uses a terminal I/O board for connection to the DC controller and for sensor inputs. The sensor inputs are for door open and door close. Additional inputs can be used for positions in between.

The Raspberry Pi only has one PWM (Pulse Width Modulation) for speed control. I use one R-Pi for dome rotation and a second R-Pi to control the door. This allows the door controller to be mounted on dome and use wireless to talk to the dome rotation controller that is mounted on the wall.

Important Note: The Raspberry Pi is 3.3 logic, the input pins cannot accept voltage higer than 3.3 and the output pins only output 3.3 volts.
The switch inputs are designed to go through a normal open swith that switches to ground. So the logic levels are inverted. Reading a logic 1 means the switch is open and a logic 0 means it is closed.

Description	Power board	build / run commands	Notes
DC motor control	Click here for amazon description Click here for amazon description	make dome ./domedriver

Raspberry-Pi Dome Driver
Hardware configuration
Using BCM Pin numbering
Clockwise button pin	23	Input
Counter Clockwise button pin	24	Input
Stop button pin	25	Input
Direction Control pin	27	Output
Power PWM pin	18	Output
Home Sensor pin	5	Input
Park Sensor pin	6	Input

NOTE: These pin numbers can be changed, this is the default list.
Pin 18 cannot be changed, it is the only pin on the Raspberry Pi that supports PWM.

These drivers require the wiringPi library, to install this library, run this script

	cd AlpacaPi 		(if not already connected to the directory)
	./install_wiringpi.sh

	gpio readall

 +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 1 | IN   | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |  OUT | 0 | 11 || 12 | 0 | ALT5 | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |  OUT | 1 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 1 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 1 | IN   | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 1 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 0 | OUT  | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 1 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 1 | 35 || 36 | 0 | OUT  | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 1 | 37 || 38 | 1 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 1 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+

Exploradome driver

To build this version

	make clean
	make expdome
	./alpacapi-expdome

	Note: on some systems, sudo may be required, this is a wiringPi requirement
	sudo ./alpacapi-expdome

Switch driver

Description	Relay board	build / run commands	Notes
8 Relay DIN mount	Click here for amazon description	make piswitch8 ./piswitch8
4 Relay	Click here for amazon description	make piswitch4 ./piswitch4
WaveShare 3 Relay	Click here for amazon description WaveShare product page WaveShare manual	make piswitch3 ./piswitch3	This board has inverted logic to the relays. A logic "0" turns the relay ON. This may cause issues on start up.
keyestudio 4 Relay	Click here for Amazon description Keyestudio 4 relay	make piswitch4ks ./piswitch4