anyone sort out a quieter fan? I'm thinking about this $15 noctua. https://www.amazon.com/Noctua-NF-A4x10-24V-PWM-Applications/dp/B0CN39MCPL/ref=sr_1_4?crid=3B8EMN4850AZC&dib=eyJ2IjoiMSJ9.ylXPI6szhYc8gCndWqU9YG-2w7PhhRX6gUVoaA8FZbbA6utTxGGKtqwLkdn24uZYR6gsQRpkNA6wCIjmzbzX_-RwRg5SkEvnAyBngfZXEvKPnZPfiiqz_bP8Vvo5koReCPhN_xdvLGQ1F8_8oyqXHX44tlPQbxVv0_LxcT-h_3kYegjwuwQGVKjjtpsGpKvHejS-hWL2GpUcopbyfTx1gKCVgZOzPsCY_k1oLoJT4Kv3_MS3Fxi_l8qfgCrHfKXrl6UVNF8hkaKYkouYrg8BQaPAgAlHSMh-N2Jcsa9_Cg8.4Wd_gPlRxe_ciPl5ZlU2VyGWWKeKZBwdVAvgIKVwnIc&dib_tag=se&keywords=40mm+24v+fan+mx&qid=1750798773&s=industrial&sprefix=40mm+24v+fan+mx+%2Cindustrial%2C70&sr=1-4 comes with speed limiter in box (Zener diode maybe) that gets you to 4100 rpm vs the stock 7000 rpm. easier than wiring into the arduino for temp control....

I was looking at the AR4 robot and was curious how the Teensy was able to control the stepper motor drivers while only outputting 3.3v on its GPIO pins. From my knowledge the drivers are best driven on 5v so how can the Teensy control the stepper motors while only outputting 3.3v?

With a ar3 robot arm running a teensy 4.1 and a arduino nano for external i/o's. Output triggers for a relay board are working fine. However how would I add an input trigger that's wired to the nano into the run program?