Spectrum Next LED inserts…..Big steps

I’ve been updating the Dev group on facebook more regularly than here

Progress has been slow but constant!, the new Jumper method of getting the LED inserts to connect to the controller works well, if a little fiddly. I think there’s some changes I can make to allow for an easier installation experience.

A big milestone also – The BETA hardware is at such a point now that i’m happy to send it to the core Dev team for actual installation inside a Next….err, except they can’t have the bottoms on as the USB cable doesn’t fit, D’oh!, another re-design needed!

AND – software – My Arduino code’s finally quite stable – Also, from the Next side of things – the i2c code is great – it runs well at 14MHZ, allowing for some interesting sequences on 8 segments…..I’ll start uploading BASIC programs in the next month or two.

Also, a kind of fork in the road….

Throughout this project, I’ve had an end goal of maybe 5-10% of Next owners owning a Blinkenator. at 3000 Nexts, that’d be maybe 150-300 devices sold over a year or two, making my beer money fund quite happy

Things recently changed……and have made me realise that I’ll probably need to step up my game a little…..

The Latest Kickstarter………. https://www.kickstarter.com/projects/spectrumnext/zx-spectrum-next-issue-2

Means that now, there’s over 8000 Nexts in the wild!.

Assuming the same targets, I’d now need to manufacture between 400 and 800 devices…

May not sound much – but at a top level, for just 800 units…….that means some big numbers…..

sourcing 3,200 Plastic inserts….

Sourcing 26,000 LED’s

and with big numbers comes Big Money….and long lead times.

IF someone landed me with an order for 800 Blinkenators tomorrow, at (say) 45 minutes per board, I’d need 600 hours to complete the order.

I have a day job that demands my attention for 160 hours a month. Wife and kids that demand me for a further 80 hours a month…then there’s the whole sleeping and eating thing..

It’d take me a year to be able to fulfil that order 😛

So, the fork in the road……….I may need to do my own Kickstarter!

I’m investigating larger scale manufacture – Full PCBA including through hole, better DFM and Plastic Injection moulding.

All that costs big up front ££…..hence the Kickstarter………is my 5-10% adoption figure massively optimistic. Is it woefully inadequate?

To have any chance at a successful Kickstarter, I need to turn this hobbyist , good quality (7/10, could do better) project into a slicker experience, a better presented finish and professionally produced, not at my dining room table package that would obtain a Crash Smash award, a solid 9.5/10 experience. I KNOW I’m capable of creating the hardware (i’ll learn the software). I’m genuinely uncertain at this time if I would be able to DELIVER that package.

Saying that, I know my limitations, I have a grasp of the fundamentals and i’m costed to the penny for small batches.

Extrapolating that upwards and figuring out where costs stand for different adoption rates is my focus now the BETA 1 boards are ready.

If 30% of Next owners buy this thing, that’s 1800 hours of ‘work’ to do. That’s a FULL TIME JOB!!

scary isn’t it. I have to create budgets that allow for an employee!!

The Beta Board – installed
close up of the new connection method for the LED’s
another closeup
A big milestone – SIX Beta Boards
8291 times a routine ran from Basic without crashing at 14MHZ!!

The Spectrum Next LED Inserts

The spectrum Next has a new Kickstarter! Currently sitting about 1.2 MILLION!!

And, the professionally produced LED inserts PCB’s have arrived at Bleugh.Biz HQ

Tiny! That’s a British 10p
The Resin printed plastics fit perfectly

One slight error on my part, I forgot to ask them to send individual pcb’s, meaning I have to hand cut out 600+ of them :-p

But, they Fit and give me back a tiny amount of space for me to make the walls of the inserts thicker…

Happy!

Zx Spectrum Next Blinkenlights …inserts arrived!

Not a huge post this one, just a quick couple of photos

A bit more diffused! Still a bit more work to do
It’s tiny! That’s a British 1p. 8 LED’s
Lots of hand soldered inserts ready for the dev boards.

The inserts fit perfectly into the case also. I’m going to experiment a bit with diffusion methods, surface finishes and colours.

I picked up about 80 of the inserts so plenty to experiment with and get the dev boards done

Spectrum Next Blinkenlights – PCB’s arrived and First Light

A christmas tree creation for a JLC PCB competition

and i’m well chuffed to say – they’re almost alive!

There’s a few teething problems however,

My ‘excellent’ idea as can be seen on my last post – https://bleughbleugh.wordpress.com/2020/05/19/spectrum-next-light-strips-more-first-light/

to use some PCB grounding spring contacts to provide a quick fit connection didn’t really pan out – the contacts simply didn’t solder on easily, too difficult to align correctly and quite weak – I tore a few pads off trying to get them aligned and correctly ‘grippy’ on the insert.

multiply that by 16 each board – the first one took me about 2 hours to get to be in an ‘ok’ state – Not really acceptable for a mass production product – not that this’ll be mass production but I’d rather not spend half a day on each of these getting them ready for sale……..

The second slight issue – See the photo below

The PCB is laid out on top the next board in the position it’ll be installed in.

There’s a prize for someone that spots the goof-up

Have a further look at the PCB powered up………..

First Light! – The board works 🙂

Yeah, I got the inserts ‘back to front’ – That’s the result of working on a bottom mount PCB from the bottom…….

There’s two ways I can fix this

Simply rotate each LED by 180 degrees on the PCB and install a bodge wire to swap the input and outputs around………

OR….

I can simply re-design the LED insert and improve upon it!

a few reasons to re-design,

The first 6 LED version still has a bit of point brightness – I fear that even with the SLA printed inserts it won’t be diffuse enough..

Some statistics

8 LED’s – This should spread out the light more, reducing the hotspots a bit

0.4mm Slimmer – this lowers the LED’s further into the case, allowing much more plastic to sit above. I’m hoping this will de-focus the light more

Reversed connections to match the reversed controller board!. reversed is the new non-reversed now 🙂

New insert PCB’s are on order and should be here in a couple of weeks, I’ve bitten the bullet and ordered FIFTY….Also a few hundred more LED’s and a large tube of solderpaste.

Doing these first 10 dev boards is going to be fun – 320 1.5mm LED’s to be hand soldered!

The Controller board fits inside the case almost perfectly

I’ve slightly offset the J15 connector on my PCB to the one on the next. This offset gives a lot of friction, but needs some long term testing – the standard header I installed on one of my boards seems to work well as a friction fit. BUT, i’m not convinced that 32 LED’s, each pulling 5-20mA, (depending on which datasheet I refer to) – or between 160-800mA total depending on how I end up setting the brightness…..800mA is a LOT to pull

I’ve purchased a new gadget – A Riden RD6006 Benchtop ‘power supply’ so once i’m set up, i’ll charaterise the LED’s and current draw to set the software limits appropriatley

I doubt i’ll take nearly an amp on this board 😛

One further small mistake on the dev board –

That 3V3VCC – it should say just VCC

When originally designing this controller board, I was to use a 3.3v Arduino to make it compatible with the Next’s 3v3 i2c.

For a few reasons, I’ve changed to using a 5V arduino and putting on-board a level translator device – this gives a 5V buffered i2c output that anyone can easily plug into

I forgot to change the net names….The board still ‘thinks’ the Arduino is either powered from RAW (it’s ‘unregulated input’) or 3V3 VCC…

The RAW input drops a few volts through a voltage regulator on the arduino to give the arduino a nice regulated 5V.

The next output is 5V….it’s not enough to power the Arduino through the RAW pin…

Took me quite a while – and a bit of soldering hackery to figure that one out as the speccy picked the board up perfectly when patch wired in place..

USB powered, it works perfectly

in the Next it doesnt….

The fix – I think I can just short the RAW pin to the unconnected VCC pin on this first batch –

and, finally

See that i2c device, found at address 0x45………..That’s the Blinkenlight 2000 PCB :-), alive and inside the Next!!!

Spectrum Next Blinkenlights – part 5 – More PCB’s

Specnext inserts - 4mm Hole drilled - Bottom Up looking
One idea that I may need to do –  Partially Drilling out the 1.6mm holes to a wider diameter – to allow for easier Inserts PCB manufacture

 

Specnext inserts - 3.2 mm Hole drilled - Top Down
Potential idea – drilling out the hole from the underside – you can almost double the diameter without touching the case – This could be quite tricky to get right though…

 

 

Continue reading “Spectrum Next Blinkenlights – part 5 – More PCB’s”

Something on the side – Spectrum Next Blinkenlights

Back a few years ago (wow, it was that long!) I backed the Spectrum Next

Problem is, those lovely coloured bars over on the righta2ql6z-spectrum-next-black-1.39

They’re not LED’s………….

Well, I’m gonna try to fix it……

Continue reading “Something on the side – Spectrum Next Blinkenlights”