This is an update to my previously-built Logitech 4000 SC1 modification in 2011. Note that the modification was originally designed to work with Parallel ports. Since such ports are now obsolete, changes to the circuitry have been implemented to allow the modified camera to be connected to newer laptops via USB ports (by using a USB-to-Serial Port adapter).
It is strongly recommended that you read the article about the previous version of this camera (link provided above) along with the comments left by the readers as this will give you a brief background as to why this update is necessary. A lot of details in this page will not make sense to you if you are not familiar with the history of the project.
WARNING: I assume no responsibility for any damage caused to your camera/equipment by following the information presented here. Keep in mind that success cannot be guaranteed even if you have followed the instructions exactly as described. This modification must be attempted only with those who are comfortable working with electric circuits. Proceed with caution and follow instructions at your own risk.
Modified Logitech 4000 SC1 (using Serial port interface)
This photo shows how the components are connected together. The box shows the components that will be placed together in a project box/case.
Click here to view a larger image. This diagram shows how the components are connected together. I have placed actual photos on Martin Burri’s diagram (used with permission) to help visualize the connections. Note that in this modification, the Parallel port is replaced by a Serial port. The rest of the circuit remains the same. To see how the previous version of this camera was wired and inspect the difference between the two circuit diagrams, click here.
Internal components about to be placed inside the housing. Note that an optional USB hub was used to minimize the wires leading to and from the housing.
A photo showing the main board of the camera, the 4066 IC, and the wire that connects them to the Serial port (an adapter) and the USB port of the laptop.
Here’s a closer look at the optional USB hub. Note that the wires have been soldered directly onto the board to save weight and minimize space. The brand of the USB hub is CD-R King.
Another view showing how the components are connected together.
Here’s a closer look at the USB-to-Serial port adapter along with the BC547 transistor, 330 ohm resistor, and the IN4148 diode. The 9-pin male port was removed and the connections were soldered directly on to the board to minimize weight and save space.
Here’s the project box (with holes drilled at the appropriate places), the webcam-to-telescope adapter, and two mounting screws to hold the adapter in place.
Components about to be placed inside the casing (Left to right: USB hub, 4066 IC, Logitech 4000, Serial port adapter)
Just enough space to accommodate the components. Note that only one wire leads out of the camera: the wire that connects the laptop to the USB Hub (thus, without the optional hub, two wires will lead out of the camera).
Front view of the camera. The two screws hold the webcam adapter securely onto the casing.
Three optional LEDs were installed on the side of the housing. The green LED connects to the built-in LED of the USB hub. The yellow LED connects to the built-in LED of the webcam. The red LED connects to the GND and Pin 7 of the Serial port (using an appropriate resistor) to allow monitoring of the state of PIN 7 (which sends the long exposure pulse).
Install the appropriate drivers. Here’s a link to the Logitech Quick cam Pro drivers download site.
Install the autoguiding program of your choice. I am using PHD2 Guiding. Select the appropriate camera from its menu.
Select guide camera. Choose “Long Exposure Serial Webcam” to tell PHD Guiding how to appropriately handle the camera.
Select the port into which the guiding signals will be sent. If you are not sure, simply play around with the ports and use trial-and-error. Also, check the appropriate boxes.
Test your camera! Shown here is an initial test conducted in November 2015. I have yet to guide a deep-sky capture using this modified “serial port” SC1 camera. It may have to wait for a while though, as I am currently unable to visit a dark-sky site for some DSO imaging.
Logitech 4000 SC1 Modification (Parallel Port)
Home-built Autoguider Project
For featured photos, click here.
For tutorials on how to get started with astrophotography, click here.
For DIY astronomy projects useful for astrophotography, click here.
To subscribe to this site, click here.
© Anthony Urbano (Manila, Philippines)