DAVEga: Battery monitor, odometer, speedometer

[totalgeek9224]

Love the collab going on here. I’d love to help in anyway possible! Keep up the great work guys

[Andy87]

I thought you speak about the proton or photon. The other guy who made a display too… Looks like I understood it wrong

[moon]

Yeah I was talking about designing a case for this, it looks like @mmaner is going to do it so I will leave it to him

[Andy87]

Than forget about what I said… Sorry for that.

[mmaner]

Im happy for you to do one too, its not a competition

[Skunk]

More opinions are always a good thing

[moon]

Yeah ofc, I love open projects so let me know when you have critical dimensions and I will also try something. I think there are some dimensions online for the display. I would probably design a case for the display and arduino so waiting for pcb aswell

[mmaner]

I think its going to have to be an inclusive model, meaning meaning both pieces actually cannot be split as there is button that needs to be accessible from the display section but connects to the arduino.

[Skunk]

@mmaner @moon whem making the mount, if you’re going for over the truck like x things. Please keep in mind spacing for those who mount drop through. Maybe a small second piece to act as a riser so those that dont mount drop save the exta few mm of height.

[mmaner]

good idea, will make the gasket difficult, but I think it can be solved.

[Skunk]

Thanks bud

[AreaKruzer]

Hey janpom,

Great work so far. I was wondering if using a SMD Atmega2560(Arduino mega processor) would be good.

The atmega have 4 uart ports. Meaning 2 vesc can feed data into it to do a coulomb counting and also possibly forward the data using another uart connected to the bt module

Also instead of writing the data of the EEPROM, is it possible to write it onto a microSD? Of cos EEPROM, will write faster than a microSD,but at least microSD will be easier to replace as compared to the EEPROM, which is the chip itself.

[Jake2k17]

This is pretty awesome man, nice job. Is there any way to convert the measurements to Imperial instead of metric?

[janpom]

I’m still thinking what would be the best way to distribute the parts. The main components are the PCB, display, chip, and USB-UART adapter. As for the latter three, we don’t really save anything by me doing the distribution since everyone could order those themselves from AliExpress (or similar) with free shipping. For example:

• display
• chip
• USB adapter

What remains are only small parts, such as

• 10k resistor
• 20pF and 100nF capacitors
• 16 MHz crystal
• diode
• pins / headers / JST connectors
• PCB spacers

Each you can get like 100 pieces for $1. Unfortunately, if you need just 1, it’s about the same price. So it does make sense to make kits with these, but at the end of the day, the savings will likely be less than $5 per kit. Not sure if it’s worth it.

The PCB is the only tricky one. I think it will be much more expensive if everyone orders their own. Please correct me if I’m wrong. And then if one person (me) orders all the PCBs to distribute to others, it makes sense to distribute at least the small parts as well. What do you guys think? I have never done this before so some advice would be much appreciated.

[janpom]

There are definitely many ways you can do this. I tried to keep it simple. SMD would be difficult to solder for some people (me included). MicroSD is a valid option, but why bother if the EEPROM lasts for 10,000 km after which you need to replace a $2 chip?

BTW, the display does have a MicroSD slot. I haven’t looked into this, but maybe it’s possible to wire it to the PCB and update the firmware to use it instead of the EEPROM.

[janpom]

@Jake2k17

Is there any way to convert the measurements to Imperial instead of metric?

I don’t have it implemented, but it’s straightforward. I’m putting it on my todo list.

Though I would recommend that you guys really start rethinking this imperial units idea.

[deucesdown]

@janpom

imperial units

I used to feel this way, but amazingly, this blog post (and the comments) really made me think. Imperial has its advantages.

Metric Vs Imperial - The English Woodworker

I’ve now readjusted my stance, and have an absolute mess again. lol.

[deucesdown]

from comments in above,

Base 12 and base 16 divide into more equal parts then base 10, metric only divides by 2 and 5. This means it is MUCH easier to think proportionally using imperial. Halves, quarters, eighths, thirds (in the case of inches) and sixteenths, easy in imperial, next to impossible in metric. I work in professional theater, I’ve seen dozens of designers from overseas, (metric using countries) that can’t see proportionally. Their designs tend to look like your looking at them through a warped lens. You can work proportionally in metric, you just end up with some weird numbers, which as mentioned in this article, can be hard to locate on your layout tools, and aren’t standard sizes of materials or hardware.

I took a lot of physics in college, loved metric for that.

The divisibility of 12 is a major advantage of inches and feet. 10 is only divisible by 5 and 2, but 12 is divisible 2,3,4,6 (and sort of 8). This makes measuring 1/4, 1/3, 1/2, 2/3, 3/4 of a length much easier with feet & inches. Consider that there are 360 degrees in a circle for similar (but not quite the same) reasons. This is not accidental. Metric seems easier to us today in the age of digital calculators, but in the age of mechanical dividers and slide rules, 12 segments is superior. The imperial system is not arbitrary or random, as I had long suspected; it has a logic of its own.

[Skunk]

I would definitely prefer MPH, but its not a deal breaker

[thisguyhere]

@janpom

And then if one person (me) orders all the PCBs to distribute to others, it makes sense to distribute at least the small parts as well.

absolutely agree. if you could source the parts, get the PCB printed, etc, then mail in bulk to one person in north america.

does not make sense for you to send these out individually across the ocean.

in terms of assembly, from your photo in the original post, looks like components are through-hole mounted? if so, i can try assembling one and maybe take on the task of kitting them out for people on this side of the world.