I am running my GTT at 115200 over the ttl connection. When the unit is sending a touch response for touch region 1 the communication flows as follows:

<0xFC><pause ~690us>
<0x87><pause ~900us>
<0x00><0x02><pause ~500us>
<0x00><0x01>

Is this typical. It was timing out my hardware FIFO. I have worked around it, however it makes the code a little less pretty and requires 4 RX interrupts versus 1.

Hi Phil,

The GTT will require some time to determine what type of event occurred to cause a response to the host, how many bytes that response will be, and finally the data to be sent back. The numbers you have listed do not sound unreasonable.

For your hardware fifo, you might consider a state machine to keep track of what data is expected next, perhaps you can find a way to save a few interrupts.

Thanks,
Troy

Hi Troy,

Thanks for the fast reply. I was just making sure I was not missing anything. I have been getting spoiled lately with MCU hardware FIFOs.

On another note I have been using the GTT for a year now as a proof of concept testbed. I would like to use it in my company's higher budget specialty diagnostic equipment(used in-house), however capacitive touch would suit my needs a bit better. Any plans on a capacitive model in the future. I would be willing to fork out more than double the price.

Thanks

Phil

No worries Phil,

We're quite flexible with custom units here, if you'd like to swap out the resistive screen for a capacitive one please send an email to design@matrixorbital.ca outlining what you'll need and we'll find a solution.

Thanks,
Troy