The beauty of using the THT is that you can easily solder any additional sensors directly to the MCU pins.
I don’t think it’s worth it to make an designated space on the PCB for ADC add-ons since the size, number of pins, pin distance, etc would vary. However, I could route the unused ADC pins (and maybe the VCC and GND as well) to the border of the PCB so that the add-ons are easier to connect. These new pins could possibly replace the DEBUG pins, which I haven’t even used myself yet and I actually don’t think they are very useful after all.
Scrolling is complicated, but toggling between multiple screens with a button would be fairly easy and I do like the idea. In fact, I believe the display layout will be the most common thing people will want to customize. A good way to design this would be by making the display layout a pluggable module. People could then contribute various display layouts as plug-ins. The end-user would be able to select the layouts they like, register them all to their Dave FW and toggle between them with a button.
Since OOP (C++) is natively supported by Arduino, this would be easy to implement. It’s a matter of defining a sharp interface for the display layout (which is already done to a large extent anyway) and have multiple implementations as class objects. Plus, class inheritance would come handy.
Just noticed something. My screen seems to be different. These two guys are smashed against each other. I still have enough meat on the bone to solder. Is this going to be a problem @janpom?
@SeanHacker I looked at the pics of your display that you have posted. It’s indeed different from mine. Is it 2.0" or 2.2"? Do the mounting holes align with the holes on the PCB?
I searched on AliExpress and found this one that looks exactly as yours from the bottom. And that’s the 2.2". If it worked with the Arduino, it should be all good, but if it’s 2.2" it won’t fit into the enclosures that @mmaner and @lrdesign are designing
I have many updates. The most important is that the USB adapters arrived yesterday (the pile in the back) and with that I have all the major parts for the kits. I’m still waiting for crystals, resistors and capacitors, but those I can buy for cheap even in the local electronics shop, which I will do if it doesn’t seem like the missing packages arrive in the next few days.
I opened one of the USB adapters to inspect it. The quality doesn’t look great. The USB connector is bent and there’s some dirt on the PCB. You probably can’t expect much for $1. I think I’ll open and test all before shipping to people. It shouldn’t take that long.
I’ll start the thread for the first batch soon, maybe tomorrow.
Yep. Looks like you’re right. I ordered the 2.2". Dammit. Bought 3 of them too. lol. Probably just going to order some 2" later at some point. Let me know when you’re selling your kits. I’ll buy one or two from you also.
It’s just a test print and the print quality is pretty bad, but it was nice to be able to get hands on it and see how well Dave fits in. I like @lrdesign’s design a lot. Simple and practical.
It would be nice to make it slightly slimmer, so that 20mm bolts can be used more easily. They work even with the current, but it’s a very tight fit.
The space for 3mm protective glass seems a complete overkill to me. Even the 2mm acrylic I have purchased seems too much. I’m actually thinking if it wouldn’t be best to go without any protective glass at all. It’s not like the display is made of sugar and if it gets damaged, it gets damaged. It’s 5 bucks.
If there’s no protective glass it can be slimmer and it would be easier for people to make. Just print it, add bolts and nuts and done. No need to cut and glue glass. The display would probably be easier to read as well.
I’ve been using headers to connect my display to the PCB since the day one. Since I’ve been developing the thing, being able to access the PCB under the display was critical for me. I think it’s actually a good feature to have for anyone. At the very least, you can easily replace the display if needs be.
The problem is that the headers add a lot to the thickness. I looked if there’s something that could be done about it and turned there’s a very simple solution. It’s a matter of removing the yellow plastic and cutting the pins.
It then still holds in the headers and allows for thin enough fit.
I’ll post in here when I am. Note the kits will come without the display though, so you’ll need to order the 2.0" anyway. Or you can just use the 2.2" for science. You already have a nice enclosure for it anyway.
@SeanHacker One extra feature of the 2.2" display is that the brightness is customizable. You could add a jumper wire between the display LED pin and one of the PWM enabled pins on the MCU. Then in the Dave FW, specify that pin number here and adjust the brightness here.
Can you post pics of your wiring to flash firmware to the board? For some reason all I get is “avrdude: stk500_recv(): programmer is not responding” when trying to flash the firmware from the programmer.
I think it would be fine depending on your usage. The goal of my design is to be waterproof and robust. 3mm was overkill, now I have it with 2mm, but 1mm might be ok. The first iteration was quite thick overall as I was guessing many of the dimensions.
I am hoping to laser cut some screens once the design is finalized. I just need to fix a friends laser cutter.
The update now is 17mm thick for the top shell and 20mm bolts do fit now.
I figured out a way to test the LCD without soldering it on. I have not put on the external wires yet but really wanted to see if I could get it working and try the arduino stuff. I stuffed a tissue in the end which put pressure on all the pins for temporary testing.
I had one issue compiling the sketch at first it said “davega_display.h” was not available. After I downloaded all the files the display.h was there but it was not in the davega folder. I moved all the extra files into there and it worked. I also needed to install the drivers for the programmer.
♂
You already have a nice enclosure for it anyway.
