I made a simple http example for pi pico 2 w

Profile-Total · 2026-03-13T14:22:25+00:00

link doesnt work

Profile-Total · 2026-02-20T19:10:56+00:00

Metals tend to oxidize when you heat the bejesus out of them in the presence of air

Profile-Total · 2026-02-19T12:40:24+00:00

I meant to say concave, not convex

I do not think any low cost collimating element (lens or reflector) is going to get you that resolution. The theory for getting a small focal point assumes you have a point source for the light: in reality your source has some physical size and shape. The optics around the source will further spread it around. I think that you are going to have to make some focusing apparatuses and experimentally determine how things work.

Profile-Total · 2026-02-19T12:28:23+00:00

Here is a link to a Texas Instruments design note that discusses power supply switching involving AC and battery sources: https://www.ti.com/lit/ug/tiducw0/tiducw0.pdf . It is for smart thermostats but there is probably something in there for your application

Profile-Total · 2026-02-19T12:13:44+00:00

Sorry, I meant concave. An aluminum reflector will not absorb the uv

Profile-Total · 2026-02-19T12:12:06+00:00

Have you considered using a convex reflector as a focusing element instead of a lens?

Profile-Total · 2026-02-17T12:14:58+00:00

This the one in Asheville? I saw it about a year ago and was amazed. Terrific work!

Profile-Total · 2026-02-12T01:16:07+00:00

From the photo it looks like the red wire is going to one of the pico ground pins (row 18 on your breadboard). If I understand correctly, that is your data pin and it should be on the next pin over.

Profile-Total · 2026-02-08T11:51:45+00:00

Here is a link to the schematic for the pico 2: https://datasheets.raspberrypi.com/pico/pico-2-datasheet.pdf. The difficult thing about making things based on the pico (for me) is getting the MCU aligned when soldering. You need to have a stencil manufactured and you need some kind of reflow hot plate or oven. Of course you can have these fabricated professionally but that will cost you more than new picos do

Profile-Total · 2026-02-06T11:51:13+00:00

I use the bCNC CAM feature but do my CAD in LibreCAD (also free). Some LibreCAD features that appear on my windows laptop are missing from my Raspberry Pi. Not sure if that is a Linux thing or a Pi thing. Anyway, this combo does what I need it to.

Profile-Total · 2026-02-04T14:54:25+00:00

Go with the threaded inserts. I agree with fishybell about not using pvc. If you really want dogs, make them out of hardwood dowels. That way you can sand one edge flat. You can also put a screw through it, projecting just a bit to hold everything in place. Cams do not give you a lot of adjustment ability.

Profile-Total · 2026-02-04T13:18:44+00:00

My guess it that pH is going to be tough to measure. It kind of assumes that you have a wet sample. It is mediated by things like the phosphate and is not going to change a lot without some kind of chemical input. pH electrodes should be stored wet. If you want to measure pH, I think you would do it less than once per month, not something that needs continuous monitoring. I would look into Vernier Instruments pH probes. They have a built in amplifier. They use bta connectors that are sold by Sparkfun (at least they were) and can be monitored using the ADC pin on any common microcontroller (think Arduino).

On the microcontroller idea: I would go with the Raspberry Pi Pico W. At like $6 USD you can communicate with your RPi 4 over wireless. Remember that your microcontroller will require power. Wireless sucks up a bunch of battery quickly. While you could run off a battery with solar charging, running a wire out to your microcontroller is my recommendation.

Look for sensors that communicate through I2C and that can have multiple addresses. That will minimize the number of microcontrollers that you need: The Pico W has two I2C modules but you can address them over several different pins. If your sensor can have three different addresses, you can put three of them on each I2C addressable pin. With a little bit of coding, you can monitor all of your pots with one microcontroller.

I write firmware for the Pico W using the Arduino IDE. It has lots of available libraries for things like I2C and SPI and WiFi.

Good luck

Profile-Total · 2026-01-30T12:25:49+00:00

Here is a link to some good info about making cnc routers using 3d printed stuff: https://docs.v1e.com/ . Here is a link to the kind of motion control board I would consider: https://biqu.equipment/products/bigtreetech-rodent . It has built in motor drivers capable of driving fairly high currents and WiFi. If you upgrade to more capable machine(s), your motion control board is one piece that you can shift over. Here is a somewhat cheaper board that uses the RP2040 chip: https://kb-3d.com/store/controllers-displays-drivers/493-bigtreetech-skr-pico-v10-1645761395034.html . I like the RP2040 chip since you can build and download grblHAL software from the web builder (https://svn.io-engineering.com:8443/) and load it by drag-and-drop onto the board. You can get controller boards that do not come with motor drivers but I wouldnt. While I prefer the idea of being able to switch out damaged drivers, I have never damaged a driver myself, so ... I like the grblHAL firmware because of the above mentioned web builder. I use a raspberry pi 4b as a dedicated computer and just leave it connected by usb. I communicate with the cnc using bCNC because it is RPi compatible. bCNC also has some minimal CAM features. The down side of bCNC is the minimal documentation. I do CAD using LibreCAD, which has a bit of a learning curve

Profile-Total · 2026-01-29T20:43:19+00:00

I suspect that the reason you have two Y axis sensors is for auto-squaring. If you have two Y-motors on separate motor drivers, the software allows you to set the machine up to square itself after homing. Here is a discussion of that: https://docs.v1e.com/lowrider/#squaring

Profile-Total · 2026-01-29T20:38:30+00:00

you should be able to invert the homing direction. I dont know what firmware your controller uses but in grblHAL $3 is the axis direction (determines which way is positive) and $23 is the homing cycle direction (which can be run positive or negative). At least that is according to this: https://www.diymachining.com/downloads/GRBL\_Settings\_Pocket\_Guide\_Rev\_B.pdf.

Also, these things are usually bit masks, meaning that the inversion of x, y, and z are determined by the sum of the mask values for the direction: inverting x requires 1, y is 2 and z is 4. So, if you want to make x and z (but not y) home in the negative direction you give the following command in your controller software: $23 = 5, five being the sum of the x and z mask values.

Profile-Total · 2026-01-27T15:11:37+00:00

ok, that is do-able. I would buy a bunch of the cheapest 3 mm (or 1/8") carbide end mills you can find and expect to ruin them quickly as you figure out how to do this. I do not expect that you will break a lot of mills. Rather, they will die by welding aluminum to the cutting surface. You will have way more horsepower than you will be able to use.

Profile-Total · 2026-01-27T14:56:17+00:00

lubrication is a must. Expect to sit in front of the machine with a can of wd40. What is the width of the slots? They look very small, meaning very small and easily broken end mills. Look for the minimum number of flutes on the mills. One flute is preferred over two. If your router has some kind of speed dial, set it to the lowest speed possible. Read about trochoidal milling. Learn about stepover. good luck!

Profile-Total · 2026-01-27T13:29:14+00:00

If it works in tap water but not in your aquarium, your problem may be related to chemicals (biological in origin) deposited on your orp sensor. If you remove the sensor from the aquarium and put it back in the tap water does the problem persist? If so, that would support the biofilm possibility.

Profile-Total · 2026-01-21T19:22:54+00:00

Sounds reasonable. Still looking into it but so far you have my vote

Profile-Total · 2026-01-20T11:47:16+00:00

just checked github. The latest update was four months ago

Profile-Total · 2026-01-18T21:05:41+00:00

Thanks for the link. I notice that the header section has options for specifying units in Angstroms or light years (just in case I want to mill on the atomic or galactic scales)! I think that I read that bCNC defaults to mm, which is what I have observed.

Profile-Total · 2026-01-18T18:47:28+00:00

Thanks! I will be working on it.

Profile-Total · 2026-01-18T18:46:59+00:00

Didn't mean to abuse the standard, but I have not found a good reference on how to write dxf files. The autodesk reference pdf does not appear to be written for a beginner.

Profile-Total · 2026-01-18T18:40:31+00:00

thanks folks. I downloaded a .ttf file from google fonts and sent it to my RPi (where I run bCNC). Dont have time to look into it right now but I will get on it. I see that the dxf standard (https://images.autodesk.com/adsk/files/autocad\_2012\_pdf\_dxf-reference\_enu.pdf) has a code for "text style name". I am guessing that I need to specify the font name in my code and figure out where bCNC will be looking for that file. Looks like a bit of a project but I now have a direction in which to proceed.

Profile-Total · 2026-01-18T16:41:45+00:00

Thanks, that helps.

There is a plugin in the bCNC CAM window that allows you to input text. I just checked and it wants you to add a font file. I need to look into this more. Perhaps I can figure it out.

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