THANK YOU! couldn't have made this without all the help from this forum!

[plasmaninjaa]

Hey guys, some of you might remember a while back the endless questions I had on topics such
as RGB leds, serial communication, frequency adjustment, circuit designs etc...


I would like to officially present to you the result of all that hard work! https://www.youtube.com/watch?v=CapW1XaoJUU



It was 2 years of struggling and asking questions. As a high school student back when I started, I had zero schooling on electronics (and still don't!).

But with the help from this community, I was able to overcome all the complications and questions I had,
to finally have a fully working prototype that will be taken to market!


Cheers and thanks! You know who you are.


(if you have any questions about the design, feel free to ask)

 

[Goeytex]

What a very nice project!. One of the best I have seen with a Picaxe.

I wish you success in your marketing endeavors.

Goey

 

[RexLan]

Priced right you can probably sell 1-2 million units fairly easily.

Be careful or someone will steal your idea and take it out from under you. I dislike shysters but it may be pertinent to see about a trademark or some form of protection.

 

[eclectic]

significantly snipped

(if you have any questions about the design, feel free to ask)

Probably iconoclastic, but,
from my personal (English) point of view,

how much are you willing to share
with the Forum?

e

 

[HertzHog]

Perhaps you should say what your project does. It is a fancy LED light for a board?

 

[plasmaninjaa]

Priced right you can probably sell 1-2 million units fairly easily.

Be careful or someone will steal your idea and take it out from under you. I dislike shysters but it may be pertinent to see about a trademark or some form of protection.

Yeah, it is in the works of getting a patent asap.

 

[plasmaninjaa]

so I guess I should go over the design.
Basically I am using a surface mount 28x2 (I will be converting to PIC to bring down manufacturing costs).
The picaxe communicates to a ws2803 chip which is an 18 channel PWM driver which drives the leds under the touch screen and the two 12v LED strips.

The touch screen is a methode I invented for myself. It consists of 5 touch pads which are printed on a transparent film using conductive carbon nano-particle ink.
Here is the print out of the touch pads:


the terminals of the pads connect to pins on the circuit board which connect to 5 pins on the 28x2 which detect touch.

This means I have a fully functional touch screen which costs pennies to produce.

 

[plasmaninjaa]

Perhaps you should say what your project does. It is a fancy LED light for a board?

Longboarding is essentially a very popular version of skateboarding where you ride down hills (more cruising and speed than tricks). The boards are longer.

It is incredibly popular in the USA, and when I lived there for a year at school, it was all anyone wanted to do at night after school.

The problem was, with no breaks and in the dark, there is a huge safety concern with getting hit by a car.

I had some pretty close calls, so I decided to make myself more visible by putting some green led strips and a 12v battery to the bottom of my board.

I was instantly "the coolest" and all the other longboarders wanted one. So I figured I had a business.

2 years, and some hardcore designing later I have a marketable product!


It is such a cool and unexplainable feeling to be cruising down a hill at night with the cool air. It feels like your flying! And the underglow just adds to that effect. Makes it feel like your on a hover board.

 

[RexLan]

I assume you built in a simple on-board charging circuit so the board can be plugged in at night to charge the battery ......

 

[RexLan]

so I guess I should go over the design.
Basically I am using a surface mount 28x2 (I will be converting to PIC to bring down manufacturing costs).
The picaxe communicates to a ws2803 chip which is an 18 channel PWM driver which drives the leds under the touch screen and the two 12v LED strips.

The touch screen is a methode I invented for myself. It consists of 5 touch pads which are printed on a transparent film using conductive carbon nano-particle ink.
Here is the print out of the touch pads: View attachment 17496


the terminals of the pads connect to pins on the circuit board which connect to 5 pins on the 28x2 which detect touch.

This means I have a fully functional touch screen which costs pennies to produce.

To me that is beyond clever ... good for you.

I would like to see how this is done and how did you make the physical connection from your graphic overlay to the PCB. Also, did you use a common ink jet printer and what substrate did you use for the overlay?

I can see a great application for this in a lot of DIY projects for everyone. The face is generally the problem and if you can incorporate touch pads replacing keypads or buttons - the possibilities are endless. You can also reverse print the window for an LCD or LED display and incorporate it all in one laminate applied to almost any project box.

I've made a fair amount of overlays but I have always reverse printed (silkscreen) the lexan sheet and the process is difficult and complicated. Using an ink jet printer seems to be simple.

 

[plasmaninjaa]

I assume you built in a simple on-board charging circuit so the board can be plugged in at night to charge the battery ......

it is just a 12v lipo battery with a 12v dc jack connected in parallel.

it will come with a 12v adaptor.


one cool thing is you could technically put this in your house or anywhere! just order like 10meters of led strips and plug them in! run it continuously off the 12v adaptor!
Doesn't have to be just for longboards, and you can use as much length of LED strips as you want, limited to the current rating of the power adaptor

 

[plasmaninjaa]

To me that is beyond clever ... good for you.

I would like to see how this is done and how did you make the physical connection from your graphic overlay to the PCB. Also, did you use a common ink jet printer and what substrate did you use for the overlay?

I can see a great application for this in a lot of DIY projects for everyone. The face is generally the problem and if you can incorporate touch pads replacing keypads or buttons - the possibilities are endless. You can also reverse print the window for an LCD or LED display and incorporate it all in one laminate applied to almost any project box.

I've made a fair amount of overlays but I have always reverse printed (silkscreen) the lexan sheet and the process is difficult and complicated. Using an ink jet printer seems to be simple.

Thanks! I really appreciate that! That was the biggest challenge I had to overcome is how to make a cheap touch screen!

I actually got a company to silkscreen print them for me. I don't think there is any technology yet to inkjet carbon conductive ink, only silver (which is like $1000/500ml!!!!)
The carbon ink i'm using is from china and is only $30/L!

As for connecting it to the PCB I just used spring-loaded connectors from digikey

 

[plasmaninjaa]

btw here is where i bought the ink from http://www.alibaba.com/product-detail/High-Conductive-Carbon-Screen-printing-INK_1955943637.html

don't have them do any printing for you though. the quality of their prints is crap, but the ink works well if you use a local professional silk screener

 

[Jeff Haas]

Those are nice LED strips - where did you get them? I got a sample recently but they were not mounted as close together, so certain effects are not as good.

 

[bpowell]

it is just a 12v lipo battery with a 12v dc jack connected in parallel.

it will come with a 12v adaptor.

Do you have any protection for low-voltage on the battery? LiPo's don't like getting too low.

Also, you're charging just by putting 12V on it? No charging circuit?

 

[plasmaninjaa]

Those are nice LED strips - where did you get them? I got a sample recently but they were not mounted as close together, so certain effects are not as good.

they are from alibaba, however they are pretty standard. They are ip65 i believe (ip means what kind of weather protection they have and 65 means soft flexible silicon covering)

The LEDs are 5050 smd and they are I believe 30/m


So just go on aliexpress or whatnot and look up 5050 smd rgb led ip65 and you should find some. Also the ones I use for the project have a black pcb.


Here's an example of one with white pcb: http://www.aliexpress.com/item/EOSS-Lighting-5M-waterproof-12V-SMD-5050-150Leds-RGB-LED-Strips-30Leds-m-free-shipping-with/2053964688.html



Also, if you're looking for an LED strip where you can individually control each LED look up the ws2812b led strip. Much more expensive, but pretty cool!

 

[plasmaninjaa]

Also, you're charging just by putting 12V on it? No charging circuit?

Yep, seems to be working fine.

 

[JimPerry]

IP65 means dust and water protection - 6 is complete dust 5 is heavy seas or strong jet of water.

 

[westaust55]

IP65 means dust and water protection - 6 is complete dust 5 is heavy seas or strong jet of water.

To International standard IEC 60529 upon which many other countries base their own version.

 

[RexLan]

it is just a 12v lipo battery with a 12v dc jack connected in parallel.

it will come with a 12v adaptor.


one cool thing is you could technically put this in your house or anywhere! just order like 10meters of led strips and plug them in! run it continuously off the 12v adaptor!
Doesn't have to be just for longboards, and you can use as much length of LED strips as you want, limited to the current rating of the power adaptor

I already use LED strips in my coffered ceilings at the house and mu kitchen for under counter lighting ..... they are dirt cheap and work really well. Converted an old PC power supply to run a 12v bus in the house for the lights.

Too bad about the ink jet printer. I can do the silkscreen but that is out of reach for average home DIY projects.

Good job. Be careful and you stand to make a handsome sum.

 

[Armp]

Do you have any protection for low-voltage on the battery? LiPo's don't like getting too low.

Also, you're charging just by putting 12V on it? No charging circuit?

Yep, seems to be working fine.

You don't indicate in which country you're located, or where you expect to sell this product. In my experience as a design consultant I urge you to be very careful with 'Product Liabilty' issues when using LiPos.

 

[plasmaninjaa]

You don't indicate in which country you're located, or where you expect to sell this product. In my experience as a design consultant I urge you to be very careful with 'Product Liabilty' issues when using LiPos.

Im in canada, but the biggest longboard scene is in the USA.
And yes, now that most of the elctronics and design is sorted out, I'm faced with the new venture of marketing /selling and business side of things which will provide tougher problems then I ever faced in the design portion I'm sure!

 

[srnet]

I recall building a longboard in around 1966, from a discarded oak shelf, a roller skate and some nails.

At the time LEDS were hard to come by though.

 

[goom]

LiPo batteries are notoriously sensitive to under discharging and over charging.
Feeding them with a "constant" voltage for charging is asking for trouble. There is a real danger of fire/explosion.
Over discharging will permanently damage them.
Please consider a proper LiPo charger and a low voltage cut-off for your own sake for the sake of your customers.

 

[Technical]

it is just a 12v lipo battery with a 12v dc jack connected in parallel.

it will come with a 12v adaptor.

This setup is dangerous. Just youtube 'lipo battery explosions' such as this, model aircraft people using a correct charger can still have problems, let alone a design that is not using a charger circuit at all!

https://www.youtube.com/watch?v=k9mcNvOGKtI

 

[plasmaninjaa]

LiPo batteries are notoriously sensitive to under discharging and over charging.
Feeding them with a "constant" voltage for charging is asking for trouble. There is a real danger of fire/explosion.
Over discharging will permanently damage them.
Please consider a proper LiPo charger and a low voltage cut-off for your own sake for the sake of your customers.

SORRY GUYS

I don't know why, I completely forgot. The lipo batteries I am using have a very small protection circuit built in. It protects from overcharging, undercharging, shorting etc...
So I have never had to worry about any charging circuits.

 

[srnet]

I don't know why, I completely forgot. The lipo batteries I am using have a very small protection circuit built in. It protects from overcharging, undercharging, shorting etc...So I have never had to worry about any charging circuits.

Wrong !!!!!!!!!!!!!!!!!!

Those Protection circuits are not, I repeat NOT for charge control, they are safety circuits designed to protect against explosion, when the proper charging circuit, that you should always fit goes wrong.

The circuits do prevent against extreme overdischarge, but at such a low voltage around 2.4V per cell typically, that the cell is toast anyway.

For even reasonable life out of a Lipo the low discharge cutoff needs to be around 3.0V per cell or possibly higher.

 

[eclectic]

Just to make absolutely sure,
could you supply the datasheet for the

"never had to worry" batteries?

I'm just imagining a scenario.

Driving at 60 mph.
There's a fire at the side of the road.

There's a nasty bump under my wheels.
I stop and look back.

A skateboarder lying in the road.

 

[techElder]

plasmaninjaa, solve your battery problems by looking at remote control vehicle sites for batteries and chargers.

Sites such as Hobby King ( http://hobbyking.com ).

 

[plasmaninjaa]

Just to make absolutely sure,
could you supply the datasheet for the

"never had to worry" batteries?

I'm just imagining a scenario.

Driving at 60 mph.
There's a fire at the side of the road.

There's a nasty bump under my wheels.
I stop and look back.

A skateboarder lying in the road.

I get them from china. I was told that the circuit it comes with is a charging circuit so no external charging circuit is needed.
I have used these batteries for years for other projects with no problems.

With a product involving risk like this, a tonne of money will have to be spent getting it completely looked over safety-wise, getting it safety approved etc...

I'm not that guy, I design. Trust me, there is probably a lot more wrong with the design than just the battery at this point as I just finished the first prototype.
I'm already finding tonnes of problems with my code and circuit design and all kinds of things, which will all get weeded out overtime.

trust me, this won't ever be commercially sold until it is fail proof

 

[plasmaninjaa]

Just to make absolutely sure,
could you supply the datasheet for the

"never had to worry" batteries?

I'm just imagining a scenario.

Driving at 60 mph.
There's a fire at the side of the road.

There's a nasty bump under my wheels.
I stop and look back.

A skateboarder lying in the road.

haha I hear you

 

[srnet]

I get them from china. I was told that the circuit it comes with is a charging circuit so no external charging circuit is needed.
I have used these batteries for years for other projects with no problems.

Well they would say that would'nt they ?

Doubt the supplier in China knows what the circuit is really for.

What does the data sheet say about the low voltage cut off level, and what is is the actual value ?

 

[Jeremy Harris]

There are quite a few cells being sold with built in charge/discharge protection now. I have some (intended primarily for use in torches/flashlights I think) that have come from various Far Eastern sources and they all seem to use much the same protection circuit. AFAICS, this is identical to the protection scheme that's used in many tens of million of consumer devices with lithium polymer cells.

As long as you only need modest amounts of discharge current they are a good choice for projects, as they are pretty safe to use. Similarly, many of the common laptop size cells (18650) are now made with a remarkably safe chemistry, ever since the infamous Sony laptop problems of a few years ago. Not good for high output current requirements, because one way they limit the risk is to change the chemistry to limit the discharge rate (and hence limit the risk from over-heating if shorted) but ideal for most projects where you only need up to a couple of amps or so.

There are an awful lot of old horror stories around about lithium cells, the vast majority of which relate to lithium cobalt oxide cells as used by the model aircraft people. These have no protection at all, are often of dubious quality and do present a substantial risk if not charged and discharged within the right limits. I've used a lot of them (as in many hundreds) in high power projects and have never once had a catastrophic failure, but I have had a LOT of duff cells over the years, and had I not always used a proper battery management system that works at the cell level I'd probably have had a charge-related incident, may be even a fire.

After a few years of working with lithium cells I'm convinced they are no more dangerous than any other cell type if properly managed, but their management is different from other chemistries and must be done at the cell, rather than the battery, level, unlike lead acid, nickel cadmium or nickel metal hydride, where you can get away with battery level management for strings of a few cells in series. The only two battery related incidents I've had were with lead acid (overcharge by human error leading to a battery boiling dry) and nickel metal hydride (over charge from a charger fault that led to a pack exploding in the early hours of the morning and then catching fire very dramatically).

All batteries pose potential hazards, but if managed sensibly and carefully can be made safe. After all, pretty much every household in the country has many devices with lithum cells in, from 'phones through to laptops, hand held games consoles, sat navs, cameras, tablets etc. The incidence of battery related fires and explosions, even from the really cheap stuff imported from the Far East, is extremely low.

 

[plasmaninjaa]

There are quite a few cells being sold with built in charge/discharge protection now. I have some (intended primarily for use in torches/flashlights I think) that have come from various Far Eastern sources and they all seem to use much the same protection circuit. AFAICS, this is identical to the protection scheme that's used in many tens of million of consumer devices with lithium polymer cells.

As long as you only need modest amounts of discharge current they are a good choice for projects, as they are pretty safe to use. Similarly, many of the common laptop size cells (18650) are now made with a remarkably safe chemistry, ever since the infamous Sony laptop problems of a few years ago. Not good for high output current requirements, because one way they limit the risk is to change the chemistry to limit the discharge rate (and hence limit the risk from over-heating if shorted) but ideal for most projects where you only need up to a couple of amps or so.

There are an awful lot of old horror stories around about lithium cells, the vast majority of which relate to lithium cobalt oxide cells as used by the model aircraft people. These have no protection at all, are often of dubious quality and do present a substantial risk if not charged and discharged within the right limits. I've used a lot of them (as in many hundreds) in high power projects and have never once had a catastrophic failure, but I have had a LOT of duff cells over the years, and had I not always used a proper battery management system that works at the cell level I'd probably have had a charge-related incident, may be even a fire.

After a few years of working with lithium cells I'm convinced they are no more dangerous than any other cell type if properly managed, but their management is different from other chemistries and must be done at the cell, rather than the battery, level, unlike lead acid, nickel cadmium or nickel metal hydride, where you can get away with battery level management for strings of a few cells in series. The only two battery related incidents I've had were with lead acid (overcharge by human error leading to a battery boiling dry) and nickel metal hydride (over charge from a charger fault that led to a pack exploding in the early hours of the morning and then catching fire very dramatically).

All batteries pose potential hazards, but if managed sensibly and carefully can be made safe. After all, pretty much every household in the country has many devices with lithum cells in, from 'phones through to laptops, hand held games consoles, sat navs, cameras, tablets etc. The incidence of battery related fires and explosions, even from the really cheap stuff imported from the Far East, is extremely low.

thanks for the input. Could you link me to your battery source? It's always good to compare prices, especially on the most expensive component of each unit.

also the batteries I am running are 2000mah 11.1v I believe.
And yes with this project, the current draw is always going to be very low

 

[Jeremy Harris]

The safest cells with built in protection are the 18650 laptop size cells, and any of the good name brands will be pretty bulletproof. They are only single cells, though, so you do need to arrange a system to charge each cell separately. You cannot easily just wire these in series to get the voltage you want without some form of charge balancing system (discharge should be fine, as they have discharge protection usually).

I know of no 3S 11.1 V pack with built in protection, 99% of them at that voltage are lithium cobalt oxide with no built in protection, especially if they are marketed for the model aircraft market, and are probably the most risky cells around if charged without a proper cell level BMS system or dedicated charger. Such a 3 cell pack needs a charge control system that ensures that no cell ever, ever, exceeds 4.2V on charge, with an active shut off or shunt system to make absolutely certain that no cell voltage can exceed 4.2V. Similarly, for discharge protection (which isn't really a safety issue, just a cell protection one) there needs to be a system to cut the power from the battery pack if any cell drops below about 3.4V as an absolute minimum (I set mine to never go below 3.6V, really to give a longer life).

 

[plasmaninjaa]

The safest cells with built in protection are the 18650 laptop size cells, and any of the good name brands will be pretty bulletproof. They are only single cells, though, so you do need to arrange a system to charge each cell separately. You cannot easily just wire these in series to get the voltage you want without some form of charge balancing system (discharge should be fine, as they have discharge protection usually).

I know of no 3S 11.1 V pack with built in protection, 99% of them at that voltage are lithium cobalt oxide with no built in protection, especially if they are marketed for the model aircraft market, and are probably the most risky cells around if charged without a proper cell level BMS system or dedicated charger. Such a 3 cell pack needs a charge control system that ensures that no cell ever, ever, exceeds 4.2V on charge, with an active shut off or shunt system to make absolutely certain that no cell voltage can exceed 4.2V. Similarly, for discharge protection (which isn't really a safety issue, just a cell protection one) there needs to be a system to cut the power from the battery pack if any cell drops below about 3.4V as an absolute minimum (I set mine to never go below 3.6V, really to give a longer life).

I see, I will definitely look into this further. thanks!

 

[RexLan]

Actually a couple of simple options depending on teh amount of time the unit needs before the battery can be recharged. The lights will work down in the 9V range so a single or dual 9V battery setup would work. They can be simply removed for charging with a simple off the shelf nicad charger that plugs into a std. outlet.

Or this unit looks to be doable ... http://www.amazon.com/Portable-4500mAh-Rechargeable-Battery-Wireless/dp/B008UKKXRC/ref=sr_1_4?ie=UTF8&qid=1417702205&sr=8-4&keywords=12vdc+rechargeable+battery

 

[geezer88]

I've built three of these into projects:

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=41163

They will properly charge two or three cells, and balance the charge for each cell. They take an unregulated 12volt DC input. I've only used them for old laptop cells, and if the cell is undervoltage or bad they will blink a light at you. The only downside is the really sketchy instructions, but for less than $5 US, I'm happy.

tom

edit: By the way, your project is AWESOME! Excellent work.

 

[Jamster]

I can't help thinking that with those lights you're going to get pulled over for impersonating a police officer

Absolutely love it