While many of the Arduino platforms are great tools for gaining easy access to microcontrollers, there are a few downsides. Price and availability may be the highest on the list, and for those reasons, some have chosen to deploy their own open-source Arduino-compatible boards.
The latest we’ve seen is the Franzininho, an Arduino Gemma-like board that’s based on the ATtiny85, a capable but tiny microcontroller by Atmel in a compact 8-pin configuration. This board has everything the Gemma has, including a built-in LED and breakout pins. One of the other perks of the Franzininho over the Gemma is that everything is based on through-hole components, making the assembly much easier than the surface mount components of the Gemma.
It’s worth noting that while these boards are open source, the Arduinos are as well. It’s equally possible to build your own 100% identical Arduino almost as easily. If you want more features, you can add your own by starting from one of these platforms and do whatever you want with it, like this semi-educational Atmel breakout board.
Thanks to [Clovis] for the tip!
Comparison with the Digispark?
Or with SILSPARK https://hackaday.io/project/10037-silspark
PCB thickness to fit USB port? 2mm? I didn’t see option to get different PCB thickness on OSHPark, they seems to offer only 1.6 which would be a bit loose in the port.
You could add a large, grounded pad on the other side of the pcb and solder a thin metal shim to it, tune to fit.
Or a tiny piece of gaffa tape…as I have been forced to do…in a production environment…
I don’t like PCB USB connectors.
They never give a reliable connection, and damage the USB ports over time.
The pic is from the first version. Check it out their github account, they have a second version with an solderable USB connector.
Or stick a 0.4mm thick square of plastic on the other side.
Months later – Educational institutions who have been searching for a virus that has been disabling USB ports find that the USB ports are gummed up with chewing gum.
Last time I ordered from oshpark, they switched my order with someone else’s and then my boards had broken traces that were 25 mils. Ive switched to pcbway, which is Chinese, but they let you customize a lot, including board thickness, and they’re a lot cheaper and faster order to recieved time.
I’m unimaginative I know but what does anyone do with the Attiy85 other than flash LEDs?
How about a CanBot?
https://arduinoproject.net/arduino-project-attiny85-canbot/
Making a variable speed rapid fire adapter for Atari 2600 controller. It’s still in the early stage. One controller (Hot Stuff line) I have has only fixed speed, the timing sucks for a few games. There are rapid fire adapter with variable speed but it’s rare and long out of production so something new, cheap, and easy to make would make a few hundred fans happy, And it won’t need anyone to mod the system or the controller.
I did this with a 555 back in the late 70’s, who needs a microcontroller?
LONG LIVE ANALOG!!!
You could likely do this with a cam operated switch and a crank, who needs electronics?
LONG LIVE ELECTROMECHANICAL!!!
I have a couple in use:
1) In several spots, to convert a potentiometer into the 1-2ms pulse required for an RC brushless motor speed controller. You could use a RC servo tester, but they are inconvenient with the speed controllers as they require an initial arming sequence. I have the ATTiny85 programmed with all of the signals and delays to arm the motor, and also do some limiting of min and max speeds that the user can select.
2) As a MPPT tracker for an electronic skylight. The ATTiny85 is connected to a H-Bridge which generates a modified square wave suitable for low voltage AC dimmable LED downlights, and by changing the duty on the wave I can have the power consumption of the LED’s match the peak power point of an external solar panel. As the sun gets weaker or brighter the downlights change in response. It looks pretty cool :)
Also just in general, the ATTiny85 could be used in many situations to replace a 555 timer, but with greater finesse and versatility
8K of 8-bit code is actually a heck of a lot. Give a Hackaday search for ATtiny85 and you’ll see that people can do anything with ’em.
Not much RAM on the tiny85, but that’s probably the biggest limitation. OK, maybe pinout, but that’s what shift registers are for. They’re my go-to micro for projects that need one thing done. I don’t use them for the hard math, but for injecting a little smarts virtually anywhere, they’re fantastic.
I’d wager that an ATtiny85 is sufficient for the majority of all Arduino projects out there. (The “you could have done it with a 555” ethos is silly, so shine on you crazy Arduinos! Get it done however you get it done!)
Probably true but a pro mini clone is the same price as an tiny85 and without looking i guess you get two clones for the price of one shift register.
Nah. Tiny is _much_ cheaper, and a shift register is $0.50. Still, your point is taken. If you’re only going to be saving $1, you might as well stick with the devil you know.
But if it’s size, or doing projects in bulk, or whatever that you care about, there’s an application for the small parts. There’s a reason that Atmel/Microchip still makes them…
I think you are paying too much for your shift registers. I’ve seen $1 for 10 74HC595 DIP, and $2.50 for 100 SOIC.
A year ago I found 500 DIP for <$10 that I couldn't ignore. Not that I have a use for that many, so I may donate some to a local hackerspace or college.
The t85 costs more than a STM32f030f4p6. Try the t13, which can be found for about $3 for 10. I like straight AVR C, but you can even program them with the Arduino IDE if that’s your thing.
https://github.com/mcudude/microcore
Neat, my brain meat has been stimulated I’m going to buy some of these :)
i used one to act as a battery monitor on my pi tablet. another one was an i2c joystick for the raspi. i also used one to control a relay once, but that kind of blew up so we dont speak of that.
6 gpio pins are sufficient to do a lot of things. a 1-wire temp sensor chain, a couple I2C humidity sensors, and a serial link, for example, for enviro monitoring in a paper handling machine.
4 channel servo controller with serial input
Two (or three, or four with a little more work… more than that gets to the point of requiring more extra hardware and a processor with more GPIO pins makes sense) channel stepper control with serial input and basic path planning. Tell it where to go and is gets there from here in a straight line.
Just for a few
Also mini theremin (no other components): https://mitxela.com/projects/a_tiny_theremin
And RFID: https://scanlime.org/category/projects/rfid/
I’ve used as the brains behind some fun timer projects (for eg, reading a button and controlling a motor as well as, I confess, blinking some LEDs)
TV-B-Gone, always popular. It is just flashing an LED, but in a clever way… :)
Infra-Red receiver of remote controlled lamp. Features: IR or local button press turns on/off. Set intensity by PWM. Turn off after 15 mins if buttons are not touched. Turn on and off has a nice fade in/out effect.
Works with a Tiny with internal clock – so the whole thing has very few components.
But it is not an ATTiny85 (who needs that much horsepower?) but an ATTiny13 with 1 kB of program memory :-). I have ported this application from an Arduino to Attiny13. Why? Because it was there.
Actually this is a very useful lamp when we have to take care of our baby in the night. We have been using the original Arduino based one for multiple years and now I have decided to “downgrade” it to a Tiny without losing any features. This is the source code: https://github.com/rizsi/Arduino-IR-decoder/blob/master/IR_reader_tsop4838_ATtiny13A/ir-rec-tiny.S
I have built a classic wired AC 8V doorbell (the one with an electromagnet) repeater to a 433MHz wireless doorbell on it. The original functionality of the doorbell was not affected. It runs on the same sets of 3x AA batteries, since i deployed it about 4 years ago :)
“One of the other perks of the Franzininho over the Gemma is that everything is based on through-hole components, making the assembly much easier than the surface mount components of the Gemma.”
I beg to differ. Besides all the drilling you have to do for through-hole I find soldering SMD components (if not too small) way more convenient. No holding down components while flipping the board around, no leads cutting, etc.
Schematic’s on github, I plan to redo the board with all SMD parts and let Chinese place do the dirty work with chemical.
The 85 can be an arduino with no external components – open sourcing a carrier pcb seems… Okay, I guess.
I was hoping for a discussion of the Teensy line of boards. Not much bigger footprint, but really nice when you need some oomph to your project.
For more power at low cost, look at stm32. You can buy 10 blue pill boards for the price of one teensy.
What you say is true except for one little detail: SOFTWARE. Paul Stoffregen, father of Teensy, has contributed, and continues to contribute mightily to the Arduino code base and to many, many libraries for Teensy. The stm32 Arduino support is just now coming on line. If you want to more than blink leds, you’re kinda on your own.
“Only uses through-hole parts because surface mount is scary”
It’s not the 1980s any more. Maybe a decade ago you could get away with this but not any more. Try and keep up with the modern world, or get left behind.
There is no such thing as “a smaller, tinier, less big, space-saving, shrunk” Arduino platform (to expand the tautology). Nor will there ever be. Arduino is essentially (A) the header configuration with the weird messed-up header of the first Arduino, plus (B) a boot loader that allows reprogramming via a UART, plus (C) the programming interface based on Processing. As soon as you take one of those out, it’s not Arduino anymore.
Not that it needs to be. You can use the same ATmega 328 (or whatever) microcontroller (without the headers) in some hardware and program it the same way as you would program an Arduino after you install the boot loader. You can side-step the Processing GUI by using VisualMicro and you can use the same programming language and all the libraries that are available for Arduino, with almost no effort.
You can even do without the boot loader, use ICSP to download a binary generated by AVR-gcc or whatever. And it would still be possible to use mostly the same code and libraries, and get your device to work. You can even use a different microcontroller from a different brand and still use much of the open-source libraries.
It amazes me sometimes how many hoops people will jump through to call a project a derivative of Arduino. Don’t get me wrong, I love Arduino as a way to get beginners to program a microcontroller and quickly accomplish what they want. But is it really that hard for people to take the next step and make a project with the same software, only without the headers, the boot loader and the GUI?
===Jac