Recent content by Pongo

I'm not bothered by appearance or UI changes. From 1981 until the introduction of Win 10 I was in control of my DOS/Windows PC. I could choose what processes I allowed to run, IOW how to use the resources I had paid for. I could choose when to update the OS. I could run real time data gathering...

Agreed. They could at least have paralleled the outputs.

The totem pole output of the 555 is pretty good current sink, but a much weaker current source. I wouldn't consider it suitable to drive a power FET directly.

I use HT16K33 displays in my GPS clocks. I use i2cfast with no problems.

Why would anyone downgrade W7 to XP?

Stick with Win7, I am. Disconnect that PC from the internet if you are really worried about security but in reality so long as you don't open email attachments or web surf on that machine, and it is behind a router, the chances of it getting hacked/impacted by issues resolved by windows updates...

@Alan. I agree with you that circuit is not ideal. As posted above I have made this work more simply.

Here's one suggested circuit to generate speed dependent pulses. Those pulses might be too short for the 08M2 to COUNT in which case add a pulse stretching monostable (LMC555) or bistable. When I have done this previously I have used a simpler circuit with an inductor/choke on the ground side...

OR you could detect the spikes and use them to determine the motor rotational speed :)

What is the minimum voltage you want to What is the minimum voltage to be detected? Assume 20 volts is the maximum.

That won't help, you'll still have the full reverse voltage across D2 + R1.

Need an opposite polarity diode across the LED to avoid violating the Absolute Max Reverse voltage of 5 volts.

If you mean the LED diode then no, using that as a protection diode at those voltages is not a good idea. According to the datasheet for the 6N136: ABSOLUTE MAXIMUM RATINGS (Tamb = 25 °C, unless otherwise specified) INPUT Reverse voltage VR 5 V I would suggest running the numbers for a...

According to the data sheet for the NSI50010YT1G: MAXIMUM RATINGS (TA = 25°C unless otherwise noted) Reverse Voltage VR 500 mV

Suggest using the Sensiron SHT31 instead, Hippy has posted code for that part on the forum here.