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Q68 Expansion Card

Posted: Fri Jun 24, 2022 11:25 am
by Derek_Stewart
Hi,

It is said in another thread, that a larger case for the Q68 could allow the addition of expansion cards for the Q68.

What type of expansion would everyone want?

Re: Q68 Expansion Card

Posted: Fri Jun 24, 2022 12:51 pm
by Pr0f
I can think of a few things that mostly just involve some signal conditioning:

QL Network ports
I2C buffered/isolated outputs to protect the Q68 from unintended accidents by experimenters
Another Serial port - perhaps as RS422/3 - as there are some interesting things that can be plugged into this

Re: Q68 Expansion Card

Posted: Fri Jun 24, 2022 4:02 pm
by Derek_Stewart
:o
Pr0f wrote:I can think of a few things that mostly just involve some signal conditioning:

QL Network ports
I2C buffered/isolated outputs to protect the Q68 from unintended accidents by experimenters
Another Serial port - perhaps as RS422/3 - as there are some interesting things that can be plugged into this
The QL Network and I2C sockets were going to added.

By I2C buffered/isolated outputs, do you mean a diode in each line?

I will look at the RS422 serial port, but who writes the SER driver?

Re: Q68 Expansion Card

Posted: Sun Jun 26, 2022 9:21 am
by Pr0f
For the I2C buffering - I was thinking of some of the purpose made I2C buffer chips - since the current I2C lines are straight from the FPGA, putting some dedicated and purpose designed buffer chips in place seems like a good move if these lines make an appearance on the outside of the case...

TI have a number of chips, as to several other manufacturers - TI's range:

https://www.ti.com/interface/i2c/level- ... ducts.html

These go well beyond what a Diode or Tranzorb could offer