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Two benefits: 1) We don't accumulate errors from the delay between the timer reset and the deadline preceding it 2) In the future, we may use WAIT to wait for timer expiration, which should cause less bus activity and is should also reduce jitter - regs4740.h (TFR. TFSR, TFCR, TDHR): added more timer registers - ubb-vga.c (until): renamed to "delay" and changed to measure relative to the last deadline - ubb-vga.c (line, hdelay, frame): replaced "until" with "delay" - ubb-vga.c (hdelay, frame, session): reset the timer only once, at the beginning of the session - ubb-vga.c (frame): we didn't wait for the horizontal back porch of the last image line
Ben Blinkenlights ================= This project is a proof of concept implementation of Rikard Lindstrom's idea of using the Ben's 8:10 card slot as a general extension interface also for devices that don't speak MMC or SD/SDIO. The application is a simple LED circuit, as suggested by David Samblas. The 8:10 card slot gives access to six GPIOs, a 3.3 V supply that can be switched on and off by software, and ground. We use a simple form of multiplexing to drive ten LEDs with this interface. Note that one should only light one LED at a time. If multiple LEDs are lit, they will share the current though the common resistor, and will thus be less bright than a single LED.