extra output on 18X

[toxicmouse]

i need to use 1 input and 1 output to communicate with a master chip, 1 input to read pulse lengths, 4 outputs to activate 4 relays, and 4 servo outputs.

that totals 2 inputs and 9 outputs, just out of the capability of an 18x. any ideas on how to use an 18x and fewest extra components? is there a way to tweek one of the inputs into being an output?

has anybody got experience of using the i2c with the servo command? does it affect it like the serin?

ideas welcome, thanks a lot.

 

[hippy]

Use the Download Serial Out to communicate with the master chip. Data can be sent by using SERTXD and you can poke an SFR to set that line high or low.

<i>has anybody got experience of using the i2c with the servo command? does it affect it like the serin? </i>

I expect any effects will be of far less significance and not noticeable; the I2C does not wait indefinitely for data to arrive.

 

[atharvai]

use a serial in parallel out shift register on one output pin to control the relays. so u'll have additional 3 outputs free

 

[toxicmouse]

thanks. i doubt using sertxd with the servo command would be too wise(judging by problems with serin/serout), but poking may well be the way forward- i'll try that.