What did you build today (Pictures) ?

[dbemowsk]

@boozz I will be curious to see if I can get enough precision to do PCBs. I have yet to buy a GRBL board to control it. For now I am going to use the UNO that I have for testing just to do test runs of the servos until I get one. This is the one I have been looking at:
https://www.ebay.com/itm/Arduino-CNC-Shield-Kit-UNO-Board-4x-DRV8825-Drivers-Package-Deal-FREE-USA-SHIP/292174947187?hash=item4406fbe373:g:A0sAAOSwJThZpeKr
I will also have to figure out the gear ratios of the motor assemblies once I am done because I am sure I will need them to calibrate the GRBL setup. I know on this part of it I have about a 4.8:1 ratio from the motor to the large gear, but I'll have to figure out steps per cm or steps per mm or something. If anyone knows a good way of figuring this out I am all ears.

Thanks for the upvotes.

[NeverDie]

@dbemowsk It will save you the hassle of upgrading if you buy a control board with GRBL1.1f already built in.

[Yveaux]

@dbemowsk said in What did you build today (Pictures) ?:

If anyone knows a good way of figuring this out I am all ears.

It would expect making a large movement using a defined number of steps, and measuring the actual distance moved with a caliper will give you a rather accurate steps/mm.
However, I hope this ratio is constant over the whole range, given the 3d printed gears and expected backlash...

[dbemowsk]

@yveaux as far as the backlash, i had already thought of that. I have 2 coupler nuts with a spring in between to handle the little bit of backlash that there is. I only had a thin spring though. I want to find a stronger one.

[bjacobse]

@sundberg84
Redundancy, maybe you should get a second temp/humidity measurement device, just in case your current beer cooler temp node breaks down...

[mfalkvidd]

@bjacobse or get redundant beer coolers :) Important to always have cool beer.

[bjacobse]

@mfalkvidd
True but usually wines have a higher price and a more valuable - not starting a discussing/flame war what is best to drink...

[dbemowsk]

@mfalkvidd Can't have too much redundancy there...

[NeverDie]

Made this 12 button keypad. Requires only one analog pin to read which button is pressed, and any button press can also wake an arduino from sleep:

Consumes no power when no button is pressed.

[NeverDie]

Here's a thread which covers it in more detail: https://forum.mysensors.org/topic/8936/6-8-buttons-battery-remote-node/36

[rozpruwacz]

@neverdie what happens when you press two or more buttons ??

[NeverDie]

@rozpruwacz Well, with the sketch I wrote (see link), you'd get the value of the first button pressed, and that's it. You'd have to release all the buttons before selecting a new button.

In terms of the hardware itself, there's an order of precedence to the buttons, so at all times you'd only be able to read the value of a single button, even if more than one button were pressed. In a multi-button press scenario, the buttons of lower precedence are ignored.

It's a good question though. If you needed to read more than one button simultaneously (such as, for example, move an RC car forward and turn right at the same time), this wouldn't do it. Seems like such a circuit would be possible though, maybe even one based on simple voltage dividing like this one. Somehow you'd need to sum unique resistances for each button pushed instead of just choose a single resistance. I can imagine doing that for a few buttons on an arduino, but maybe not as many as 12.

[rozpruwacz]

@neverdie I'm asking because I Was trying to do something like this. If there was a resistor values set that would make all 2**n (where n is the number of buttons) choices spaced enough in voltage domain it would work, but I couldn't find such a set ...

[NeverDie]

@rozpruwacz said in What did you build today (Pictures) ?:

@neverdie I'm asking because I Was trying to do something like this. If there was a resistor values set that would make all 2**n (where n is the number of buttons) choices spaced enough in voltage domain it would work, but I couldn't find such a set ...

That's why it might work if you needed it for only a few buttons. With only 1024 units of voltage, seems like you'd quickly run out of resolution if you tried to do more.

[sundberg84]

I built my first MysX daughter board which I will connect to my EasyPCB to drive a led strip.
This will power everything from 12v so 2 things. Power main board and dim LED strip.

[sundberg84]

Do anyone knows it the back of a TO-220 always is connected to GND and if this should be connected to the board GND as well? Currently I have a exposed copper as a heatsink but this copper is not connected to GND.

[tbowmo]

@sundberg84

Depends on the manufacturer / device type.. So look in the datasheet of the one that you want to use.

[sundberg84]

@tbowmo
Thank you - I want to be able to use them all/different (ie. 5v, 3.3v, different manufacturer) so I wont connect it and just use it as a heatsink.

[dbemowsk]

@tbowmo I agree, it would be per device specs. In many cases I see that connected to the middle pin (whatever that may be), but not always.

[NeverDie]

Made this two-button nRF52832 remote control:

It only draws power when one of the buttons is pressed.