Paul & Sabrina's cheap DIY 144v motor controller

[dcb]

[quote=squiggles;108042 No point having the controller do any data processing that some external device can easily do.[/quote]

Well it could at least be human readable for dumb terminals, or possibly formatted for a $20 serial lcd or something. I wouldn't plan on sending out binary numbers.

But do we have to go here already?

[dcb]

I think the reason I'm hesitant about the uart stuff is because it is really utilized by such a small percentage of users, mostly developers at that. And to do it right (in a motor controller you don't have much choice) it takes some effort and space and testing and complicates things a bit, where most people will be like "hey it works, whats a uart?"

[NiHaoMike]

Originally Posted by dcb

I think the reason I'm hesitant about the uart stuff is because it is really utilized by such a small percentage of users, mostly developers at that. And to do it right (in a motor controller you don't have much choice) it takes some effort and space and testing and complicates things a bit, where most people will be like "hey it works, whats a uart?"

Serial communication is a great way to interface to a LCD or data logger.

[Tango Charlie]

Originally Posted by dcb

...where most people will be like "hey it works, whats a uart?"

*raises hand, uncertainly*

*stage whispers to Intrigued, "...or a mosfet, or an interrupt, or modbus slave type protocol, or..." *

Hey!
You guys rock! Keep up the awesomeness!

[squiggles]

Originally Posted by dcb

I think the reason I'm hesitant about the uart stuff is because it is really utilized by such a small percentage of users, mostly developers at that. And to do it right (in a motor controller you don't have much choice) it takes some effort and space and testing and complicates things a bit, where most people will be like "hey it works, whats a uart?"

I think that is the significant point. The majority of those that have an interest in the serial data will connect some sort of smart device that can handle raw data. Keep the controller process as lean as possible.

[slurryguy]

If I may be so bold as to offer a suggestion.

Serial data out (or in) would be an excellent feature for the NEXT VERSION.

Keep
It
Simple
Software gurus.

There will be plenty of time to guild the lilly as future versions come out. Get the fundamental functionality and responsible safety features working well on the first version. Worry about getting fancy with future versions.

JMHO

[squiggles]

A very valid point from the slurryguy.
Although being able to alter parameters would be a a bonus for testing / setting up.

[MPaulHolmes]

Want to see a picture of the control section?



If this thing blows up, I'm going to be real reall real mad! hahaha!

Maybe you guys are right about the serial communication. It's there if anyone wants to use it, or it could be ignored. No big deal ya!

By the way, somebody out there keeps hogging all the good mosfets from Digikey! They got their supply of them replenished less than a month ago! Maybe Curtis is stockpiling them? hehe. Now they won't ship until June 22! makes me mad!

Digi-Key - IRFP4668PBF-ND (International Rectifier - IRFP4668PBF)

[nubie]

Originally Posted by esoneson

Paul,

Why don't you have him mount sockets instead of the AtMega8's? This would make life a lot easier at this stage of the game.

Eric

I think it would make life easier at every stage of the game, they should be required on every controller. (saving hours and hours of work for under a buck is always the smart way to go.)


That control section looks

Keep it Paul, we need these controllers zooming around urban areas asap

(anybody got a source for electric forklift parts in Sacramento CA? My friend and I figured I could convert a Ranger to EV with a long chevy driveshaft linked directly to a motor, no transmission, then put the batteries under the bed and under the hood )

EDIT:

Paul, please see if you can fix the pictures on your website, you need to generate thumbnails for large photos, don't use the IMG tag to re-size, it creates poor looking pictures:

http://www.paulandsabrinasevstuff.co...e/100_0165.JPG

2032px × 1354px (scaled to 260px × 180px) Not cool.

Also, it isn't a great idea to change the aspect ratio of a picture.

I like Picasa (free from Google), it can track a ton of photos fast, also thumb-nailing them and creating smaller versions with ease.

[squiggles]

Originally Posted by nubie

I think it would make life easier at every stage of the game, they should be required on every controller. (saving hours and hours of work for under a buck is always the smart way to go.)

Certainly during development, a definite no in production though. These things are going to live in a high vibration environment, sockets not recommended.

On that note any leaded device (capacitors, large resistors) should have mechanical support in addition to their solder leads. Vibration will cause solder joints to fatigue and fracture. Support with a little glue or 'neutral cure' silicone. Be aware that some glues and silicones are acidic and will attack copper. Bad solder joints on pcb's can cause very hard to diagnose intermittent faults and believe me you don't want to go there!!