The Raspberry Pi Foundation has announced revision 2.0 of their boards. The team behind the Pi explains in a post on its website that the second revision won’t feature anything major such as a new processor or more memory, but will instead incorporate several changes based on the feedback the team has received since the original device was launched. The foundation states that revision 2.0 devices would be “filtering out over the next month as the last stocks of the revision 1.0 at each distributor and in each geography are exhausted”.
Revision 2.0 of the Raspberry Pi will feature a small change to the GPIO pin out to add ARM JTAG support and to present a different I2C peripheral from that which is used on the camera interface. We also get a reset circuit, which can be used by fitting an appropriate header to P6, as the team has not fitted the header in the standard build. Shorting P6 pin 1 to P6 pin 2 will cause the BCM2835 to reset.
Revision 2.0 of the Raspberry Pi will feature a small change to the GPIO pin out to add ARM JTAG support and to present a different I2C peripheral from that which is used on the camera interface. We also get a reset circuit, which can be used by fitting an appropriate header to P6, as the team has not fitted the header in the standard build. Shorting P6 pin 1 to P6 pin 2 will cause the BCM2835 to reset.
Revision 2.0 of the Raspberry Pi out in the wild
In addition, the resetable fuses used to protect the USB outputs on some later revision 1.0 PCBs have been removed. You can now reliably power the RPI from a USB hub that feeds back power. The team states it is important to make sure that the chosen hub does not supply more than 2.5A under fault conditions.
Two GPIO pins have been interchanged to allow a missing debug signal (ARM_TMS) to appear on P1 pin 13. In addition, the primary and secondary I2C channels have been reversed. The foundation has also removed four GPIO signals originally used for version identification as they were apparently never read by the system software and were redundant. A new connector site P5 has been added to utilise GPIO signals released by the removal of the version identification links. P5 will carry the four GPIO signals named GPIO7 – GPIO10 respectively, along with +5V0, +3V3 and two 0V. The team states that this new connector is suitable for third-party clock and audio codec boards, and “is pinned to be mounted (Ideally) on the underside due to connector clash.”Pin 1 is marked with the square pad.
Revision 1.0 had a problem with the HDMI port interfering with the correct operation of CEC on other connected devices. This was fixed on some later revision 1.0 PCBs by removing the ESD protection diode D14; the foundation has fixed this issue in revision 2.0 by connecting the top side of the diode to +5V0_HDMI. In addition, SMSC 18 power has been disconnected from the power supply.
We also get two 2.5 mm non-plated mounting holes for assistance when ATE test mounting. Two minor changes have also been made to the silk screen: D9 (Yellow LED) graphic has been corrected to 100 from the earlier 10M, while the D5 graphic has been changed from OK to ACT (Activity).
No comments:
Post a Comment