From eaf5d4799cc52e9dd1ebcaeafbf8f670658fea98 Mon Sep 17 00:00:00 2001 From: root Date: Tue, 13 Jun 2017 21:10:37 +0100 Subject: inital commit --- README | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 README (limited to 'README') diff --git a/README b/README new file mode 100644 index 0000000..ba383e9 --- /dev/null +++ b/README @@ -0,0 +1,36 @@ +To get this steaming pile of excellence working you need + +1) an STM32F103 board rated to 72MHz with an 8MHz clock and the PB6 and PB7 pins available + +eg +http://www.ebay.co.uk/itm/132170295715 +http://www.ebay.co.uk/itm/132138287991 + +2) optional (passive adaptors to get to you HDMI or DVI-D from whatever you have, the apple ones work well) + +3) Some way of connecting your HDMI/DVI-D to the board: + +HDMI DVI-D Cortex-M3 + +15 DDC SCL 6 DDC SCL PB6 (with 10k pull-up to 3V3) +16 DDC SDA 7 DDC SDA PB7 (with 10k pull-up to 3V3) +17 GND 15 GND GND +18 +5V 14 +5V (tie to HPD) +19 HPD 16 HPD (tie to +5V) + +The code connects a virtual NS16X50 uart to the I2C bus at address 0x90 (like an SC16IS7XX does), +and a 24C02 EEPROM containg DDC data for a 1280x1024 monitor at address 0xA0. + +The virtual UART is connected to the M3's real uart 1 which is enabled, and to a CDC ACM device +on USB. + +The fake monitor is necessary because recent intel GPUs do hot plug detection and powering up the ports +in firmware rather than in the driver it also tricks said firmware into configuring the port as HDMI/DVI +rather than as Displayport - that way the GPIOs that AX can see get connected to SDA and SCL. + +The USB interface also offers a DFU device for flashing the firmware without a JTAG/ST-LINK cable, +which although very slow is good because it synchronises the board reset with the USB host's rescaning +of the device, so you don't need to replug. + + +J. -- cgit v1.2.3