[Arm-netbook] passthrough card stm32f072 firmware

[Albert ARIBAUD]

Bonjour,

Le Fri, 17 Mar 2017 07:23:27 +0000
Luke Kenneth Casson Leighton <lkcl at lkcl.net> a écrit:

> ---
> crowd-funded eco-conscious hardware:
> https://www.crowdsupply.com/eoma68
> 
> 
> On Thu, Mar 16, 2017 at 3:40 PM, Albert ARIBAUD
> <albert.aribaud at free.fr> wrote:
> > Hi Luke,
> >
> > Le Tue, 14 Mar 2017 07:32:17 +0000
> > Luke Kenneth Casson Leighton <lkcl at lkcl.net> a écrit:
> >  
> >> sorry albert just checked the schematics and also watterott's
> >> HDMI_Display schematic - it's HDMI DDC that the STM32F072 needs to
> >> emulate!  but looking at the watterott schematics that's just an
> >> EEPROM (again).
> >>
> >> l.  
> >
> > OK, I'm lost :) and not really familiar with the passthrough card
> > so let me try to find my bearings back; just stop me when I'm
> > wrong. The goal is that the passthrough card advertise on its HDMI
> > connector's I2C the display capabilities of the microdesktop it is
> > slotted into. Correct?
> >
> > So at the interface level, it should behave as an I2C slave EEPROM
> > wrt DDC_SDA and DDC_SCL (that's I2C1 on the STM32) and as an I2C
> > master wrt the EOM68 connector's I2C. Right?  
> 
>  no, ignore the EOMA68 connector entirely - that has nothing to do
> with this.
> 
>  the pins are the ones i listed.  which is *NOT* the EOMA68 I2C pins.
> it's two *SEPARATE* pins which is why it really should be done as
> bit-banging.
>
> > Now, what I am not sure about yet is whether there are any
> > conversion to be made between the I2C data read from the
> > microdesktop(s I2C and the data to be provided on the HDMI DCC
> > IC2.  
> 
>  nnnope!  i would have said.  it's very very simple.  just straight
> "read EDID data from EEPROM then replay EDID data from EEPROM.".
> 
>  that's all that's needed.

OK, got it now.

There is no firmware started yet for the passthrough card at
git at git.hands.com:eoma-firmware, right ? So I'll start from scratch.

> l.

Amicalement,
-- 
Albert.