Again, a one page schematic that shows most of the differences between the B+ and the B model is available and easily found on this site. That schematic does not include any of the new
USB interface circuits apparently for no particular reason other than they do not want to which is a sad departure from the much more friendly attitude of earlier times. This change in attitude
has also carried over to the new Pi 2 model B where it appears that they do not intend to publish any schematics for it at all.
Any and all attempts to discover why these schematics have not been published is met with utter silence both on this forum (which is monitored by Element 14 personnel) and the Raspberry
Pi foundation forums which leads me to believe that they have no intention of doing so. It would be nice if they would at least come out and make their intentions known preferably with some
sort of explanation, reasonable or otherwise, as to why.
I recently purchased an ODROID-C1 which is a good alternative hardware wise to the Pi 2: ARM 1.5 GHz quad-core with a proprietary GPU, 1 GB RAM, micro HDMI, 4 USB 2 ports, 100/1000
Ethernet interface, mostly compatible 40 pin GPIO connector (pins 37 - 39 are used for an Analog to Digital interface), no camera interface. It has schematics available and documentation
for the SoC although it is new and lacks the community, commercial product support and "buzz" that has grown up around the Pi so in those ways it is at a serious disadvantage.
You wanna lock something down then do what they are doing, keep the design a secret. Then only allow a select few access to this type of information and this will force most tinkers to buy commercialized interfaces. Which seem to be very expensive compared to the Pi. This way they can make some profit from that side of the business, then aren't making anything on the Pi. Hey they have to make a living too! I've ran into similar issues with other companies where they wouldn't release critical information about accessing data in their chips (I2C protocol). This was an even bigger problem as you can imagine. Instead the wanted me to purchase their interface board and give me their code. I of course decided to drop that chip and go somewhere else. After that I finished the project I had been working on using other ICs. Later, in my (spare time) I decided to hack the chip. That was a lot of fun and eventually I figured it out on my own and in doing so mapped the entire chip from how it addressed down to the # of registers it had. Same thing can be done here. Might burn up a few boards in the process but that's how you learn to design. So although it would be grate if they release the schematic I can certainly understand why they don't. This is just another one of those challenges that help us grow. Be grateful for what they've done to date as this Pi is just incredible. It's one of the most innovative ideas since the invention of the computer. With that in mind, having a schematic might just take out all the fun in building new interfaces and deprive us from experience that could otherwise lead us to even greater achievements. After all most of the fun is in the struggle to understand, so having a schematic is just a minor inconvenience that can be over come through careful testing. For me, the GPIO pins are the most fun as all the other stuff has been worked out. Have a great day and have FUN with your Pi.
