Date: Mon, 27 Apr 2015 12:48:41 +0200 From: Milan Obuch <freebsd-arch@dino.sk> To: Adrian Chadd <adrian@freebsd.org> Cc: freebsd-arch@freebsd.org Subject: Re: using libgpio to bitbang LCDs! Message-ID: <20150427124841.7b8a59bc@zeta.dino.sk> In-Reply-To: <CAJ-VmonT1FvoNUAAY1JeHM9LopaCiWvPBjw_ubP5Ktm0FYZBvA@mail.gmail.com> References: <CAJ-Vmo=n=Lfh_XqkxwAA43jUi7suoPjWV1uSv4VnKNncw3%2BPfw@mail.gmail.com> <CAJ-VmonT1FvoNUAAY1JeHM9LopaCiWvPBjw_ubP5Ktm0FYZBvA@mail.gmail.com>
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On Sat, 11 Apr 2015 23:45:55 -0700 Adrian Chadd <adrian@freebsd.org> wrote: > Hi, > > The library source code and a demo program is available here: > > https://github.com/erikarn/freebsd-liblcd > > It includes the wiring needed to hook the example OLED board up > (http://www.adafruit.com/products/684) to a Carambola 2 evaluation > board. > > Anything you can get 5v and 5 GPIO pins from will work. (Well, as long > as there's also libgpio / gpio API support for your device..) > > > > -adrian > Hi, I downloaded master.zip from github and now I am trying to modify it for my hardware - Raspberry PI and TFT display with ILI9341 chip https://learn.adafruit.com/adafruit-pitft-28-inch-resistive-touchscreen-display-raspberry-pi My original attempt to use SPI failed probably because ILI9341 does not use pure SPI, but there is one extension - DC pin. I did not manage to satisfy chip's timing/bit sequence/whatever, so I would like to try bit banging. I found two small issues with archive downloaded - freebsd-liblcd-master/src/beastie_ili9340c_320x240/Makefile seems to ba a copy of freebsd-liblcd-master/src/beastie_ssd1351_128x128/Makefile, I think there should be a difference, after my fix --- beastie_ili9340c_320x240/Makefile 2015-04-23 21:40:10.693847000 +0200 +++ beastie_ssd1351_128x128/Makefile 2015-04-13 00:58:06.000000000 +0200 @@ -3,7 +3,7 @@ .include <bsd.own.mk> -PROG=beastie_ili9340c_320x240 +PROG=beastie_ssd1351_128x128 SRCS=main.c CFLAGS+=-I../../lib/liblcd LDFLAGS+=-L../../lib/liblcd The second issue is when doing 'make install' binaries produced are being installed into / directory. While both are not fatal for me, they are annoyances at least. I found following in source files: /* Configured for the carambola 2 board */ cfg.gpio_unit = 0; cfg.pin_cs = 19; cfg.pin_rst = 20; cfg.pin_dc = 21; cfg.pin_sck = 22; cfg.pin_mosi = 23; I see there no 'pin_miso', so does this mean only one directional communication is being used, no status reading, or both reading and writing are being carried over one pin? If the former, then all I should to do is change pin numbers in above given excerption to ones valid for Raspberry Pi, if the later, I can't use this without more modifications. Also, I have simple monochrome display with PCD8544 chip, which should use basically the same bus design, so it could be used for this too, with some modification. Regards, Milanhome | help
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