- Dec 4, 2011
- 568
I thought I'd take a moment to document the new project I'm trying to put together and see if anyone has suggestions or helpful tips to add...
My truck has the 6-disc Bose system, however between the failing CD loader and the recent antenna problems, I decided it was time to start moving forward on a carPC. This is something I've wanted to do for awhile, so I've collected information over the years on the possibilities. I want to retain the Bose amplifier, and get a harness to hook up the steering wheel controls to I/O lines on the computer.
Overall, I have decided on using Android for the OS. I have been looking at the Radxa Rock board which is a quad-core A9 Arm with 2GB of ram and built-in 8GB flash. I will using the HDMI port initially for the display, but later may use the direct LCD lines. This board has wifi and bluetooth built in, and I have a USB GPS unit already. For the display, I've been finding some 6.5" touchscreen kits on ebay. The resolution is crap (800x480) but I don't have much experience with LCD screens so the kit seems like the best place to start. The 6.5" screen leaves enough room for a slot-load CD player. I found one of these in a trashed laptop which has everything but blueray (DVD dual-layer writing capabilities even!), and ordered a usb conversion board from Amazon for it.
For the radio, I plan to use an RTL-SDR so I can receive more than just the standard FM band. Who knows, it could be fun to see what I can pick up when sitting on top of the mountain. There are several really cheap units available (around $10) but these have frequency drift problems associated with temperature. I found a $25 unit that appears to lock in much better.
Navigation will be handled by Waze. I've been using the program on my phone and its been working great, so no reason to change. The GSP unit I have plugs into USB and has a magnet-mount antenna, although I've been wondering if I might tie into the existing onstar antenna to use instead. Will have to experiment with that when I get further down the road.
Backup camera -- fairly simple, the LCD controller board in the kit has AV inputs to auto-switch when you apply 12V to a pin. Later on I may try to handle this in software though so I can eliminate the LCD controller.
Security cameras would be nice. Mount a couple forward-facing cameras in the light bar, plus have a rear-facing camera (if I can get the backup cam to be software-controlled, I could also use it for security rather than having another dedicated camera). There are several motion-detection triggered programs that record the input, which could be stored on a local drive and transferred automatically to my servers whenever I pull into the garage and get a wifi signal.
Vehicle info could come from a bluetooth elm327 adapter and Torque... nice to have available on the screen. It would be nice if I could find a way to permanently wire the elm327 and free up the odb-II port though.
The Radxa board doesn't give much info about the audio chip, but I believe it is a 5-speaker output through the HDMI port. There are quite a number of I/O pins available for various inputs such as the steering wheel controls, and I saw one person suggest that these inputs could be mapped onto the IR port to appear as keyboard keys, which greatly simplifies the interfacing. Radxa also provides the full source code for building the Android installation, so it can be modified for the visual interface, plus adding drivers for devices like my DVD player. The board works directly with the vehicle battery, accepting something like 9-18VDC input, but it would probably still be worthwhile to regulate that input, or at least clean it up with a large capacitor. The current board does not have SATA for an external drive, but that could be handled by USB. I will need to learn a lot more about Android to set up the display with all the applications, and get it to hibernate rather than turning off when the vehicle is stopped (allowing for instant-on).
The last step will be the actual installation of the equipment. I have been looking all over for suitable 2DIN computer cases, and everything I found that I actually liked was discontinued. So I'm just going to make my own. The actual framework can just be some light sheet metal with holes drilled to support the various pieces and the faceplate. For the faceplate, I'm thinking of building a simple X-Y table for my drill press and using it as a router to bevel out the region for the display and a slot for the CD. Then I'll cut out some areas on the sides to make back-lit buttons. I saw a technique where someone used a laser printer and transparencies to print their faceplate with words and symbols left clear. I'll have to experiment and see if I can glue the printed material to my button faces securely.
Well, that's where I'm at right now. After we get through the Holidays, I'll be putting in an order for the motherboard and display, then I can start hooking up pieces as I get them. There's a LOT of work ahead but once I have the radio working there's no reason I can't go ahead and mount it in the truck at that time and add the rest as I get the hardware.
My truck has the 6-disc Bose system, however between the failing CD loader and the recent antenna problems, I decided it was time to start moving forward on a carPC. This is something I've wanted to do for awhile, so I've collected information over the years on the possibilities. I want to retain the Bose amplifier, and get a harness to hook up the steering wheel controls to I/O lines on the computer.
Overall, I have decided on using Android for the OS. I have been looking at the Radxa Rock board which is a quad-core A9 Arm with 2GB of ram and built-in 8GB flash. I will using the HDMI port initially for the display, but later may use the direct LCD lines. This board has wifi and bluetooth built in, and I have a USB GPS unit already. For the display, I've been finding some 6.5" touchscreen kits on ebay. The resolution is crap (800x480) but I don't have much experience with LCD screens so the kit seems like the best place to start. The 6.5" screen leaves enough room for a slot-load CD player. I found one of these in a trashed laptop which has everything but blueray (DVD dual-layer writing capabilities even!), and ordered a usb conversion board from Amazon for it.
For the radio, I plan to use an RTL-SDR so I can receive more than just the standard FM band. Who knows, it could be fun to see what I can pick up when sitting on top of the mountain. There are several really cheap units available (around $10) but these have frequency drift problems associated with temperature. I found a $25 unit that appears to lock in much better.
Navigation will be handled by Waze. I've been using the program on my phone and its been working great, so no reason to change. The GSP unit I have plugs into USB and has a magnet-mount antenna, although I've been wondering if I might tie into the existing onstar antenna to use instead. Will have to experiment with that when I get further down the road.
Backup camera -- fairly simple, the LCD controller board in the kit has AV inputs to auto-switch when you apply 12V to a pin. Later on I may try to handle this in software though so I can eliminate the LCD controller.
Security cameras would be nice. Mount a couple forward-facing cameras in the light bar, plus have a rear-facing camera (if I can get the backup cam to be software-controlled, I could also use it for security rather than having another dedicated camera). There are several motion-detection triggered programs that record the input, which could be stored on a local drive and transferred automatically to my servers whenever I pull into the garage and get a wifi signal.
Vehicle info could come from a bluetooth elm327 adapter and Torque... nice to have available on the screen. It would be nice if I could find a way to permanently wire the elm327 and free up the odb-II port though.
The Radxa board doesn't give much info about the audio chip, but I believe it is a 5-speaker output through the HDMI port. There are quite a number of I/O pins available for various inputs such as the steering wheel controls, and I saw one person suggest that these inputs could be mapped onto the IR port to appear as keyboard keys, which greatly simplifies the interfacing. Radxa also provides the full source code for building the Android installation, so it can be modified for the visual interface, plus adding drivers for devices like my DVD player. The board works directly with the vehicle battery, accepting something like 9-18VDC input, but it would probably still be worthwhile to regulate that input, or at least clean it up with a large capacitor. The current board does not have SATA for an external drive, but that could be handled by USB. I will need to learn a lot more about Android to set up the display with all the applications, and get it to hibernate rather than turning off when the vehicle is stopped (allowing for instant-on).
The last step will be the actual installation of the equipment. I have been looking all over for suitable 2DIN computer cases, and everything I found that I actually liked was discontinued. So I'm just going to make my own. The actual framework can just be some light sheet metal with holes drilled to support the various pieces and the faceplate. For the faceplate, I'm thinking of building a simple X-Y table for my drill press and using it as a router to bevel out the region for the display and a slot for the CD. Then I'll cut out some areas on the sides to make back-lit buttons. I saw a technique where someone used a laser printer and transparencies to print their faceplate with words and symbols left clear. I'll have to experiment and see if I can glue the printed material to my button faces securely.
Well, that's where I'm at right now. After we get through the Holidays, I'll be putting in an order for the motherboard and display, then I can start hooking up pieces as I get them. There's a LOT of work ahead but once I have the radio working there's no reason I can't go ahead and mount it in the truck at that time and add the rest as I get the hardware.