I managed to get a display bought from eBay working but it won't work when its plugged into a USB Host Shield.
The display uses all pins except for A5 on Arduino Uno, while the USB Host Shield seems to only be using the SPI pins.
Thinking the pins created a straight-through connection, something seems to be disabling the display without trying to initialize the USB Host Shield.
From pinouts, it looks like the USB Host Shield wants to use Arduino pins 9 and 10 for SS and interrupt, but I haven't soldered the jumpers to use those pins.
My only guess is the Arduino board is branching the SPI and pin 9 pathways to the in-circuit programming header. They say it can be bypassed or redirected but I don't see how if the connection is constant running through the Arduino board.
So the SS and Int pins on the IsB Host Shield are exposed and not soldered to complete a pathway to the pin headers for Arduino pins 9/10.
How does one disable the SS and Int that rein through the in circuit programmable header the USB Host Shield attaches to? My conclusion would be to physical scrape/cut/destroy the pathway coming from the in-circuit programmable header.
I'm a bit lost and don't understand how their unproframmed board stops the LCD display from working when their board provides a straight-through connection for other boards to connect to the Arduino through their board.
Anyone know how to go about fixing this? I think I might add a relay for the SS lines of the USB and LCD display so I can toggle between the devices and use A5 for the USB Host Shield INT pin.
Thanks for your help