Today wanted to start designing a net for the casing of my vending machine, however I soon realised that it was more logical to start with the core system and then build the casing around it.
To Print or Not to Print…
Printing the result is actually not a necessary step in this system. I may just relay the data from processing straight to the vending machine. Now that I have discovered that the medals are costly to produce I need to consider the best way to arrange this system.
Reasons Not to Print
– Relaying the data straight to the vending machine will stop people vending more than one medal each, this will help prevent waste.
– The system is more automatic (and impressive?) and doesn’t rely on the user
Reasons To Print
– Its more fun and adds an element of interactivity
– The print out becomes the end goal and the medal is an add-on. That way, if I do run out of medals, the user still gets an outcome. (I should print a personal analysis as well as a QR code for the medal)
Verdict: Continue with plans to print, but move the output of the personal analysis from on-screen to paper output.
I started by looking for projects similar to my own, to give me an idea as to what components would be necessary. There were plenty of Arduino printer projects online, some were build from scratch, others utilised small Arduino compatible printers.
I won’t be building a printer from scratch, so I will probably be best off with a small thermal printer. These are the types of printers found in cash registers and pin machines and work by exposing heat to rolls of thermal paper, meaning that they don’t require any ink. Thermal printers are very common, cost effective and can come in small sizes, which fits my vision for this system. After some time, the print will wear off the paper. In my experience, receipts I have kept seem to fade after a few months. This life span far exceeds what I need for this project as the print out is only useful until the medal has been dispensed. The medal itself is what the user will bring home and this has a much longer lifespan.
Pipsta is a beautiful thermal printer that is Arduino and Raspberry Pi compatible. But it is over £80 and I know for a fact that there are morse affordable (and uglier) printers on the market.
I also know that my printer doesn’t necessarily need to be Arduino compatible. It just needs to work with AppleScript. So my course of action will be to buy a more affordable printer, make it work, then make it pretty.
Earlier, Spencer suggested I look for a 5V or 9V motor. I found a few online, but I don’t know whether I will need to buy a slow (30 rpm) motor or slow down an normal one. To narrow down my search, I looked for projects similar to mine, and found the following.
- There are ‘arduino compatible’ motors available (here) although i’m sure a regular motor can be used with an arduino… so maybe it is just set up differently.
- I learned that most motors can run off the voltage supplied by an arduino, but this is lower than the usual voltage supply so the motor will run with less power (not sure if slower, or with less torque or both…)
- A motor can be powered externally from a cell and switched on and off by an arduino
Before setting off to buy the Arduino compatible motors, I talked to Jay to see if i could scrounge one off someone in the university to practice with. He let me steal one from Spencer’s desk, which will do for now.
Later in the day, I visited Spencer with my new stepper motor, and he ran me through the basics of how they work. Essentially it is comprised of four corner magnets which need to be switched on and off in the right order to spin the magnetised core. This is ideal for my project as I can completely control the speed rotation of the motor.
I was then assigned the task to go away and try to make the stepper motor work using the information I had learned today.