Yesterday, I talked about looking for a console port on the Bell ExpressVu 9200 (aka Dish 942) receiver. After completely disassembling the unit, I discovered a 5-pin pad on the motherboard labelled ‘UART’ located underneath the power supply. Interesting! I soldered a header plug and brought the cable outside the chassis.
The pin assignment appears to be as follows:
- 1. +3.3v
- 2. RxD
- 3. TxD
- 4. ???
- 5. GND
Looking at TxD with a scope shows that it starts at 0v, and after avout 3 seconds jumps up to 3.3v. It stays at 3.3v and doesn’t appear to change at all. I hooked up a MX3232 (3.3v version of a MAX232) to convert the signals to RS232 levels.
Unfortunately, I’ve been unable to coax the serial port to life. I tried sending carriage returns at different baud rates. I’ve still got to try sending a break signal. Also, pin 4 might be some sort of CTS signal that might need to be asserted. Still lots to try!
Regular readers will remember my recent attemt to hold Bell accountable to the GPL. As a quick update, I’ve received a couple of telephone calls assuring me that they are working to get the code posted to their website. As of this writing, there’s still nothing posted. Bell told me that they would be posting the same code that Dish released. I’m suspicious that this code isn’t the latest version that Bell and Dish are using. To verify that, I’m going to have to look at the actual code installed inside the 9200. Bell certainly doesn’t make it easy to get at the binaries. My first attemt involves looking for a serial console port. I’ll leave my serial port adventures for another post, but during my explorations of the insides of the 9200, I discovered something very interesting!
As I was disassembling the unit and removing the power supply, I noticed a cable from the motherboard to the supply labelled ‘Home Plug’. It’s a 5-wire cable, with a color code very similar to USB. The cable terminated in what looks like some sort of matching transformer made by Delta Electronics. Looking at their website showed that the 9200 indeed has the hardware to communicate via the Homeplug protocol. Googling shows a press release coming out talking about the feature, promising the ability to distribute satellite radio throughout the house, and having receivers talk to each other and only one needing a telephone line.
After an initial flurry of press releases, I was unable to find anything recent about this ‘feature’. It certainly appears that the receivers have the ability to talk to each other. Will Dish and Bell use this to enforce multiple receivers on one account having to be in the same physical building? It’s interesting that neither the user manual nor the website mention anything about these receivers using your home wiring to talk to each other.
Determining whether Dish and Bell are actually using this feature yet will have to wait until I obtain some HomePlug hardware to see what’s going on.