Posted on Leave a comment

Hot plate solder technique

To easily mount the sensors it is HIGHLY recommended to use the cheap solder paste method on a hot plate. A toaster oven can work, too. Even any fry pan on the stove top can work but check with the boss first. Getting the sensors well-mounted is crucial. After the flux burns off (about 7 minutes on this hot plate) a perfect silver solder job remains.

Sensors in paste before heating
Sensors in paste before heating

hot plate and solder paste

Posted on Leave a comment

All the parts

Small parts and LCD screen
Vacuum sensor
Black Label Board
Arduino Uno R3


The sensors and the Arduino board are worth shopping around for. Buy the rest from one source. The trick is to minimize shipping costs. The LCD and the small parts can be found at a decent electronics parts store (be sure of configuration compatibility for the potentiometer and reset push switch so they fit the board). Ordering from is the easiest and it beats running around looking for small parts.

Posted on

Useful information about the hexloader

The Complete Build It Yourself Package includes hex loaders for Windows and Macs. This is a tiny program that will upload the supplied hex software files onto your Arduino board so you can run the program.

An Arduino usually has a bootloader on it. A bootloader stays on the board to manage software uploads. When using one of the hex loaders, you may or may not be loading or even overwriting the bootloader. That’s fine; it just takes up space unless you are trying to load something from the IDE. Then the board needs to have a bootloader. Fortunately, the IDE has an option to first load the bootloader.

Sometimes DigitalCarbSync hex programs are supplied with and without a bootloader. Either will usually work. Sometimes the supplied hex program is too big to load directly if it also includes the bootloader. Just use the other version.

Here is some useful information about the bootloader.

Posted on

Source for plastic tube and couplers

We sell our stock of tube couplers at outrageous prices. Well, double-ish, anyway.

You may be better off buying directly from our source. They have lots of options.

It all depends on the number you want, shipping costs and convenience. If you are buying a board from us the shipping is flat rate so adding on the connectors may make sense.

These Luer connectors work. You can mix and match the sizes.

Here’s what we use: