Hi all, A few months ago, I’ve made a DIY Arduboy on a breadboard. The project was…well it was a half success. Ever since, I’ve wanted to make a new one and solder everything on some perfboard, add lipo battery/boost charger and many more things. I have some questions. The first one is, schematics. I found some schematics online. will these work?
On my ArduBreadBoy, the main board is a pro micro. I use a clone version. I am aware that the pro micro is a board developed by Sparkfun, and I always get errors about bootloaders and can’t upload to board ( and even when I can get it to work, something always goes wrong, like I have to reburn a new bootloader). If I use a genuine pro micro (Sparkfun) then will the errors stop and will the bootloader on the board be fine? Also, for charging, will the adafruit power boost 500 work well? If so, and if these schematics are good, where do I connect a 3 pin power switch, rgb led (positive anode) and powerboost 500?
I lost my password to my old account “ArdFlamingo” Lol.
It definitely does! Two actually. But It’s also pretty overkill for use in an arduboy, imo. I tend to use cheap charging circuits from old vapes, but if you want to source compnents from online instead of salvage, adafruit has a couple other chargers that should be perfect. This one is neat because the usb connections are part of the PCB, though they could easily be brought out if this was an inconvenient form factor. This one is just a basic chrager circuit that would be perfect for a pro micro. Both are WAY cheaper than the powerboost 500 and will work just as well.
Are you having to reburn the bootloader every single sketch or just once when you first use them? Sometimes pro micros will be shipped with a different bootloader than the standard arduino core for whatever reason, and you have to burn the correct bootloader onto them so that it works. However, you should only have to do this once when you first get it if you are having issues with it. I don’t think opting for the expensive name-brand is going to change much, they might just have the correct bootloader on them but really you’ll be paying for a label and some red pcb more than anything. The big issue with clones is that they use some lower quality connectors, the micro-usb port tends to come off easily as it’s only a surface-mount connector instead of having through-hole stabilizers.
Those schematics are fine but you may find these more useful and easier to follow. For the 3pin switch it’s up to you how you want your charger and arduboy to behave, but can be as simple as connecting the switch’s middle pin between the charger’s negative(-) output and the battery’s negative(-) wire, and connecting one of the side pins to your pro micro’s GND. When turned on you can and use the battery, when not it should charge.
RGB LED has 4 legs, the longest one is your common, it should be second to last from the side with a flat edge. The arduboy uses common anode which is a positive(+) lead. Connect the common anode to pro micro’s VCC. I’ve also seen people use common cathode paired with a level shifter IC, but doesn’t seem worth it imo.
I don’t know if you’ve used the RGB before, but do NOT just connect everything. It will burn out extremely fast. Each of the leds inside the led (I know, but stay with me, it’s just how it works) requires a different amount of current to safely activate it. over a certain amperage and they’ll just burn and be more useless than a paperweight. You must attach resistors to each of the pins EXCEPT common anode. Most people go with specific resistances for each color to get consistent brightness across all three. Personally, this is a waste of time when it comes to arduboy, and 3 resistors that are around 220-330ohms should be perfect, but you can probably get away with whatever you have on-hand as long as it’s at least 100ohms and less than 1kohms.
Really? You sure? In all the pictures I saw it had the place for one but I wasn’t there. I have the micro lipo (the second link) but I read somewhere on Reddit that you can only connect it through the usb port and also don’t you need 5 volts for the pro micro?
Exactly, and it’s very tedius and most of the time it can’t even upload, and will be impossible once I solder the board to everything. The one I burned is the Sparkfun 5v pro micro one with the package that has extra boards, the one that you guys told me to burn.
I have had a LOT of issues with software so the fact that it comes with the right bootloader is like free nachos. Red pcbs are cool. One time I accidently snapped off the port on my clone and im so worried that I will break another one.
Mmm. That is exactly what I wanted and needed to hear.
^from the adafruit website. The micro-usb port is what charges the battery, that big usb2.0 connector is so you can charge your phone or other device with it, because that board outputs the 5v 1a requirement for most devices. Adafruit went through an “open-source phone charging” phase, I think this is from that line.
Dont’t believe everything on Reddit, lts of people post without so much as googling what they’re talking about. The micro lipo has breakouts on the board itself if you decide you want to nix the micro-usb port to include it in a devices form-factor better. Be careful with this though. While it’s certainly more of a hassle to have two microusb ports n a device (the pro micro’s and the microlip charger in this case), it’s a lot safer. I don’t remember the exact configuration(think it has something to do with VCC vs RAW), but it’s easy to accidentally wire a lipo charger directly to the arduino in such a way that the arduino turns into a very expensive fuse that will blow out in quite a short time usually.
No. While they are rated for 5v at 16mhz, it’s not necessary, and most of the time your production arduboy is floating well below this anyways. You can check this out on any arduboy (DIY or production) using one of my favorite sketches, Ardutosh. It’s a simple Mac-II inspired desktop environment with a few useful tools and applications. Under Sys there’s an option for “Battery” which will show you a real-time plot of your current voltage draw. Checking my production one now I can see it floating at around ~3.8v, which is expected because they batteries in the arduboy are only 3.7v! (although in reality they can hold charges a bit above this, sometimes actually closer to 4.5-4.7v. Don’t ask me why.) I think the 5v label is more of a maximum rated voltage? I certainly wouldn’t go past it.
Yeah, go for Sparkfun’s then. Or if you can find another clone with through-hole USB connectors, that’s usually a good sign that the quality is decent and you shouldn’t have an issue breaking the port. It is super annoying when you get everything set up perfectly and looking nice and the * snap * all the effort is undone and the traces are impossible to solder to, I’ve had it happen too many times. At this point i end up supergluing the connector pins as soon as I get the clone
That said, I’ve never had a bootloader issue like that before! The supplier you got it from probably has a bunch of chips that are fraudulently labeled 32u4 to make a bigger profit. That’s the issue with a lot of the Chinese clones unfortunately, it’s a game of luck it seems. While I’ve never had issues, there’s others that can’t seem to get a single board that doesn’t have any.
I’m absolutely certain. All of my DIY arduboys including ones with the larger SSD1309 display work perfectly with 3.7v supply. I’ve used coin cells, vape batteries, RC toy batteries, and AAs. There’s no noticeable difference between a 3.7v supply and 5v as far as I could test. The only thing I can think might be an issue is if you decided to use extra sensors that might need the full 5v for logic. But I’ve yet to see many people add sensors to their arduboys unforutantely.