On Mon, 2013-11-11 at 12:43 +0800, Tom Cubie wrote:
On Mon, Nov 11, 2013 at 12:19 AM, joem joem@martindale-electric.co.uk wrote:
:this is not a miswire. the specification has now changed to reflect :what cannot now be changed.
5" LCD resolution 800x480 working for EOMA. Details here http://www.gplsquared.com/eoma_boot/eoma_boot.html#eoma_with_5inch_lcd These displays are about $16 from Aliexpress: http://www.aliexpress.com/item/5inch-5-TFT-LCD-LCM-RGB-800-480-Display-TOUCH...
I still notice a problem with color - Red and Blue appear to be swapped.
ok. the specification's going to have to change. we cannot modify the CPU Card, so the spec has to be changed to match the card. what a pain.
Hmmmppp...... The is another outstanding issue that needs resolving before the next batch goes into production - this time to do with the RS232 RX line. When connected, the entire board is able to power up through the RX line. The cubieboard1,2 and iteaduino plus and EOMA-A20 boards all have same defect because I assume all of them were designed and tested by the same engineering team from Wits with no peer review input onto the process.
The cubieboard1,2 are not designed by wits. All the allwinner boards including wits are following the allwinner reference design.
Hmm.. MK802 also infected - so I guess everyone is infected.
I put up suggestion for UART-RX repair - EOMAs and boards where internal 3.3V is accessible: http://www.gplsquared.com/eoma_boot/eoma_boot.html#uart_repair
Turl in freenode #linux-sunxi suggests olimex solve it with their later boards.
If you are doing another batch, make sure the CPU board RX line doesn't power up the entire board through that line. They need to put a serial resistor in series or a FET pair to sufficiently isolate the RX line. The same note applies to anyone else using designs that originated with Allwinner/Wits.
we also have the RX line powering the board problem on our rk3188 board. we use this ttl to use cable http://store.r0ck.me/products/ttl-to-usb-serial-cable and found that the serial port of 3188 is damaged when plugging and unplugging the power quickly. Further investigation we found that the ttl to usb cable is 5V and the voltage on rx can be as high as 4V. No problem using this cable on A10/A20 but the voltage tolerance for 3188 is less since it's 28nm made.