signal. OpenPnP would rather have simple analog vacuum sensors on each
nozzle, readable by one of the system's control interfaces, then implement
the thresholds in software. That that end, Bdale designed a [replacement
- vacuum board](https://git.gag.com/hw/csm84vacuum) that uses 3 NXP 4115
- series analog output vacuum sensors, intended to be attached to three of
- the "thermistor" inputs on the Smoothieboard that also provides axis servo
- control.
+ vacuum board](https://git.gag.com/?p=hw/csm84vacuum;a=summary) that uses
+ 3 NXP 4115 series analog output vacuum sensors, intended to be attached to
+ three of the "thermistor" inputs on the Smoothieboard that also provides
+ axis servo control.