Modifying a Pencam For External Control
A pencam can be easily modified to be controlled externally. The interface is simple, there are only two buttons. All that needs to be done is solder leads to the mode and shutter buttons and run these outside the camera. These leads are connected to the Pencam controller. If performed carefully the modification will leave the original buttons in place and functional. This is important as you will still want to be able to operate the camera to test it, switch modes etc.
This modification is applicable to the Pencam and Pencam VGA camera but may also apply to other types of Pencams. If the camera has a mode and shutter button it will probably work with the controller. In that case you can use the instructions found here as a guide but the details of the procedure will likely differ.
The modification requires the following tools and supplies:
- small precision philips screwdriver
- xacto knife or razor saw
- tweezers or small pliers
- soldering iron and solder
- Small wire tie or hot glue.
- 12" of 4 conductor telephone cable (AYUCR Pencam Interface Cable recommended)
Modifiying the Pencam
Read through the directions once just to make sure you are comfortable performing the modification. If you have any questions feel free to contact me.
You should have a clean, open work surface. Some of the parts are tiny. You don't want to lose them. It helps to have a cup or dish to put the parts in to keep them from disappearing. You might want to take this time to prep the wire for soldering later. Strip about 1" of the outer covering off each end and 1/8" off the end of each wire.
Remove the battery cover and batteries. Inside the battery compartment are two small screws. Remove these and put them someplace safe. These screws are tiny and easily stripped unless you use a proper sized screwdriver. RadioShack sells a set that works well.
The case is held together by three plastic tabs. One on each side and another on the top of the camera. If you persist you can get the tabs to release and the back cover will come off the camera. Note the shutter button may fall free.
There is no need for the clip. It adds weight and removing it will make the camera fit in a BT55 tube more easily. With the cover removed you can pop it out and discard it.
|Circuit Board Removal
4 screws hold the circuit board. Two on the lens assembly and two on the lower corners. Remove the lower two and CAREFULLY remove the two on the lens assembly. Remove the lens assembly and put it aside being careful not to scratch or touch the image sensor underneath. The circuit board will come free of the case by working the battery clips out of their slots. Note the mode button will fall free.
|Soldering Mode Leads
Note the mode button in the photo. You must solder two leads (red and black if using AYUCR Pencam Interface cable) to the lefthand solder pads (one each) next to the button. You don't want blobs of solder everywhere just enough to hold the leads. Pre-tin the leads with a little solder and then melt them into the existing solder joint. It helps to hold the wire with a pair of tweezers for soldering. Inspect you joints to make sure they are solid and not just hanging by a strand.
|Soldering Shutter Leads
Repeat the procedure with the remaining two leads (yellow and green if using AYUCR Pencam Interface Cable). Solder one to each of the shutter contacts. Be careful not to touch the image sensor. You will want to route the leads to the right of the shutter button. It may help to make the lead soldered to the righthand solder pad in the picture slightly shorter than the other to accommodate this.
|Removal of the Eyepiece
You will need to remove the eyepiece to make room for the leads to exit the camera. This is attached to the lens spacer so some surgery is required. Start by removing this piece by removing the small screw next to the eyepiece.
Using an X-Acto knife repeatedly score the joint between the lens spacer and eyepiece until the two separate easily. You can also saw the two pieces apart with a fine razor saw. Replace the lens spacer in the housing. Discard the eyepiece.
Make sure the mode button is in place and screw the circuit board back into the housing. Before replacing the lens make sure the image sensor is clean and free of dust.
In order to provide strain relief for the leads cinch a small wire tie onto the outer insulation. Add a drop of CA to hold it place and clip off the tail. You can also use a dab of hot glue on the wires for strain relief but a wire tie works better.
Notch the back of the housing near the top to provide a place to route the leads outside the housing. A quick way to do this is with a red hot coathanger. This will melt a groove in the plastic. Be careful not to damage the tab on the top of the housing. Trim the excess plastic around the groove.
Replace the back of the housing by snapping the tabs back in place. Route the leads out the groove you made and make sure the shutter button is in place. Replace the two screws in the battery compartment.
Test the camera again by shorting the appropriate pairs of leads together to simulate button pushes. Red and black should operate the mode button and yellow and green should operate the shutter.
Wiring the Controller Connector
The chart below details the wiring for the connector to the Pencam Controller. The wire colors correspond to the suggested wiring from the modification instructions. See the photo for the orientation.of the pins. For tips on working with crimp pins see the Serial Cable Assembly Instructions.
That should do it. You should be able to perform a final test the Pencam Controller connected to the Pencam.