Rich52 Posted February 12, 2022 Report Share Posted February 12, 2022 Using a G4X plug-in for EVO8. Please can you confirm what pull-up resister to what voltage the Ign 5 output uses when used as a GP PWM output set to active low. Although the manual referes to it as an AUX out in this case (1k5 to 12V) I get the impression it isn't this? I see the Ign out mode drives 20mA to only 5V? If there isn't a pullup can I externally pull up to 12V OK. To clarify I'm driving a 5V zener diode hoping to clamp output to a 5V PWM then onto an RC filter/integrator. I'd assumed that the output was simply pulled up to battery volts with a 1k5 resister but it isn't reachimg the 5V when in the high state. Thanks Rich Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 12, 2022 Report Share Posted February 12, 2022 In aux output mode there is only a very weak pull-up effect to about 6V on the ignition drives. You can remove the zener and add your own pull-up to 5V. Quote Link to comment Share on other sites More sharing options...
Rich52 Posted February 13, 2022 Author Report Share Posted February 13, 2022 Thanks Adam, confirms what I thought. I guess it will be happy being pulled up to 12V as its essentially just an open collector ouput? ps recently upgraded from V44 to G4X and loving the addional features! Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 13, 2022 Report Share Posted February 13, 2022 Yes it is fine to pull-up to 12V, but if you are putting a zener on it to clamp to 5V you will be better to just pull-up to 5V instead. The problem with pulling up to battery voltage is it can vary significantly which is going to have a big influence if you are trying to use PWM to create an analog output. On the proper aux outputs they are pulled up to a regulated 12V supply. Quote Link to comment Share on other sites More sharing options...
Rich52 Posted February 14, 2022 Author Report Share Posted February 14, 2022 Useful info on the use of regulated 12V. I wanted to use battery and chassis ground for my application so am using the zenor to stablise the pwm input to my device (driving a Geartronics gear display). I've now added a pull up to batt and the analog output seems to be plenty stable enough although more testing is required Thanks again. Rich ps perhaps something to consider for the manual is a bit more detail of the various drive circuits and modes? Quote Link to comment Share on other sites More sharing options...
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