I am using ST7735S.It has a 3 wire serial mode which is 9 bit in every "byte transaction, 9th bit 1 for command and 0 for data. It does have a 4 wire configuration (which would have made my life much easier), but the hardware vendor wanted it to be 3 wire mode. Can we even do this over SPIDEV in user space? I have set 9 bit word size and nothing seems to help.
On Saturday, September 21, 2019 at 8:13:00 AM UTC-4, Robert Heller wrote: > > At Sat, 21 Sep 2019 04:34:24 -0700 (PDT) [email protected] > <javascript:> wrote: > > > > > > > > > > > > > I have SPi0 and SPI enabled in device tree. I looped back shorting MISO > and > > MOSI and Can receive the send messages provided its all 8 bit word > length > > > > The issue is I am trying to talk to St7735S display driver over SPI ,it > > needs 9 bit command and data transfer. > > Are you sure about that? > > The Adafruit Arduino St7735S driver library seems to use 8-bit data and > commands and is doing 8-bit SPI transfers. And I know that works, because > I am > using it with both an Adafruit Feather M0 express and an Adafruit Metro > Mini > project (both programed via the Arduino IDE, but the driver code could be > ported to Linux easily enough). > > > > > So I am trying to send > tx1[6]={0x01AA,0x0177,0x0188,0x0100,0x01FF,0x0166}; > > , defined as short int (2 bytes) . but when I receive response its > > > > 01AA 5577 and so on. its not correct and nothing happens on display? Any > > help > > > > -- > Robert Heller -- 978-544-6933 > Deepwoods Software -- Custom Software Services > http://www.deepsoft.com/ -- Linux Administration Services > [email protected] <javascript:> -- Webhosting Services > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/c3116d34-be26-4c83-abe7-c8c2ad342161%40googlegroups.com.
