Prototype 4 (Raspberry Pi hat PCB)

[thijstriemstra]

I see a start for a 4th prototype has been started in the repository's main branch @corrados

Awesome!

Will it be an easy upgrade for users of v3? Any schematic changes? What is the plan for v4?

[corrados]

The new prototype is a Raspberry Pi Hat design similar to Exadrumino Nano Every. Here is an early model:

It uses a Roland Multi-Core instead of separate trigger input jacks.
The schematic have not changed in this prototype.

[corrados]

Prototype 4 is progressing:

[corrados]

The new prototype 4 is ready:

See the ChangeLog for details.

[thijstriemstra]

looks great!! Is the prototype 3 codebase compatible with prototype 4? Can/did you tag the old code?

[corrados]

The codebase is compatible to both prototypes. Yon can select it with a compile flag:

edrumulus/edrumulus.ino

Line 19 in cf4f507

//#define USE_PROTOTYPE3 // based on Roland HD-1 pads

[thijstriemstra]

Thanks!

[thijstriemstra]

I like the new design but it looks the Roland cable plugging into the new prototype is at least 60 euros, plus I can't re-use my existing cables. A set of 8 jack female sockets is about $15 and with some resistors it looks like a cheaper option to me. Also, the Raspberry Pi is currently in high demand and quite pricey. So to me it's a different pricepoint compared to the prototype v3 and because this project is 'competing' with other cheap edrum solutions out there I hope it'll stay compatible with the budget v3 implementations one could make :)

At the end of the day, if Roland releases a quality module that matches the price of a 'hobbyist' (my own soldering, wiring, your awesome code) implementation, what would you choose?

[thijstriemstra]

Thanks for the feedback and your vision for edrumulus.

Would you be interested in such a PCB?

For sure! I'd love to make my prototype a lot smaller by having a pcb. If you end up creating something like that, my email is in the git log and I'll send you money (paypal?) for these costs and shipping; let me know how it works, I've not ordered a custom pcb before). I also saw you had oldskool MIDI in/out female sockets planned, that would be much appreciated as well.

the cheapest Roland module with positional sensing support is over 1000 €.

Ah, I didn't research it properly and thought it was more in area of 600 euro. But that 1000 euro pricetag has to come down at some point, Moore's law etc right?! :-)

Keep up the great work!

[corrados]

For sure! I'd love to make my prototype a lot smaller by having a pcb.

Ok, good to know. It will take some time to work on this since I first want to finish the other prototype. I'll keep you informed.

[thijstriemstra]

Ok, good to know. It will take some time to work on this since I first want to finish the other prototype. I'll keep you informed.

Perhaps a new discussion topic can be started when you're ready for that; feel free to tag me there for feedback.

[corrados]

I like the new design but it looks the Roland cable plugging into the new prototype is at least 60 euros, plus I can't re-use my existing cables. A set of 8 jack female sockets is about $15 and with some resistors it looks like a cheaper option to me.

Just one more comment regarding the prices. The entry level Roland drum kits all use the DB25 connector.
In your case you already have the cables available. If you start from nothing, you'll have:

1. With DB25:

• DB25 connector: 0.70 €
• Roland multi core cable: 49 €

2. With jack sockets:

• jack sockets: 8 x 0.47 € = 3.76 €
• kabels: 8 x 8.90 € = 71.20 €

So, it is actually more expensive not to use the DB25 cables. I assume you can save some money if you buy the parts for the cables and solder them yourself. But at the same time, one could find out the cable assignments of the cheap Millenium MPS-850 Cable Loom and redesign the Edrumulus DB25 connector to support this product instead of the Roland cables. This would be half the price. But since Roland sets standards for the e-drums, it makes sense to develop the support for their cables in Edrumulus.

[corrados]

After that, I'll eventually create a new PCB which is much larger and uses normal jack sockets and also normal sized components (i.e., no SMD parts).

Here is the PCB I have created:

It is called prototype 6.

[thijstriemstra]

kabels: 8 x 8.90 € = 71.20 €

wowow, hold on :-) We should really use ebay/aliexpress for these comparisons. reichelt and thomas are 99% of the time the most expensive options out there.

[corrados]

the Roland cable plugging into the new prototype is at least 60 euros [...] We should really use ebay/aliexpress for these comparisons

Maybe you get a Roland cable clone on aliexpress for much less than 60 € ;-)