Sprockit is now available in the HackMe Store. For now, it’s only available without the case, either as a kit or as a built synth. I’m hoping to get the case done soon, but I’m waiting on the graphic design from my better half, who has presently got her hands more than full. I will make the case design, sans graphics, available for those who will be making their own.
I’ve been hard at work on Rockit’s firmware and am proud to put out Version 1.1. There are a number of improvements, bug fixes, and a new feature. I’ve also made a few adjustments/hacks to resistor values which greatly improve Rockit’s sound. Click through for a list of the software and hardware updates. Continue reading
The Rockit case is finally finished. I got the third and final prototype of the Rockit case in, put it together, and did the happy dance. I’m going to make some small adjustments for the production order, but nothing that will require another round of prototypes. I’m going to put up the case for pre-sale today. I need to hit a threshold of about 50 orders in order to buy it. The lead time from the laser cutter is three weeks, so these should ship in February. The cost will be $50. Click through for more pictures. Continue reading
Sprockit Mini-Synth
Rockit’s getting a little brother, Sprockit. My goal with Sprockit it to take a lot of Rockit goodness and compress it down to something smaller and a bit cheaper. I’m achieving both goals by having a very dense design and by reducing some of the features. Sprockit is 4″x4″ versus Rockit’s 5.1″x8.6″, so it’s substantially smaller, like pocket sized (I would’ve called it Pockit Rockit, but there are some products out there already). There are obviously fewer knobs, LEDs, and switches. All of the control parameters are still there though and will be accessible via an external MIDI controller. The microcontroller is downsized from an ATMEGA644 to an ATMEGA328. I’m also incorporating a lot of the things that I’ve learned from doing Rockit and rolling those improvements into Sprockit. This image is my first prototype and I’m well into prototype two, which will be much improved. I’ll be doing a workshop with Dorkbot Chicago at the end of February where people can build Sprockit with me. I’ll probably do another Kickstarter project after that. I’ve learned from Rockit that I’ll need to get the case designed before I release it though. Click through for a complete feature rundown. Continue reading
It was my intention to have the case ready for sale by now but events have intervened. I managed to get the design done and ordered but there were some snafus at the laser cutter and what was delivered was not what was designed. I’m getting another set made but I couldn’t get it before the holidays, so it’ll be done in January. I did get to see how the two-tone material is going to look and it’s gonna be officially dope. I know it’s been a while but this case is going to be worth the wait.
I’m working on a software update for Rockit to fix a few bugs and to improve some features. I’ve got a feature in mind to add as well, but I’m going to keep it a surprise til it happens.
I’ve got another thing in the works as well and I’ll probably announce it in the next week.
Cheers and Happy Holidays.
I’ve spent a fair amount of time detailing the hardware that Rockit uses for it’s Voltage-Controlled Amplifier. It’s a transconductance amplifier-based design and you can read about it here. I haven’t, however, discussed the software behind implementing the envelope generator. It ends up being more useful than just controlling amplitude. The same envelope generator code works for the filter envelope too. I didn’t end up using exactly the same code, but it could be made entirely modular, taking some basic inputs like timing and parameter data and returning an appropriate value for an envelope. Let’s just focus on how to code an ADSR envelope for now. If you’d like to get the source code for Rockit, please download it from Rockit’s Sourceforge Page.
I finished shipping all the Kickstarter orders. Altogether, I’ve shipped about 175 Rockits in some form. I’m happy to say that no problem that I encountered along the way was unresolvable. Everyone that has one built has it working. That was a lot of work and it’s kind of weird to be on the other side of such a monumental effort. I’ve been working 60+ hour weeks between my real job and Rockit for as long as I can remember. The real lesson I learned from doing this has been persistence, sheer dogged persistence. There were several times I sat at my workbench (kitchen table) and thought that if I didn’t figure out what was wrong pretty soon, I was going to cancel the Kickstarter project. But I just kept coming back and trying again. I did two board revisions between the beginning of the project and when it was funded and then spent an entire more month tweaking the software. I added the drone/loop feature after the Kickstarter project started! All in all, Rockit took two years of my evenings and weekends to design, and several more years of learning before I had the courage to start it. All in all, there were six Rockit prototypes from breadboard to the present board. I have a hard time estimating the amount of time that I put into it, but it must be a couple thousand hours.
Rockit is now available for sale in the HackMe Store. The case is coming along and should be finished and available in December.
So, what’s next? I’m going to be working on the software a bit to come out with a 1.1 release with some fixes, some changes, and some new features. I’ve received some requests and I’m going to do my best to incorporate those requests. Some people would like some envelope changes, some LFO changes, and I think I could figure out some surprises too. There are different oscillator modes that leave open some clock cycles that could be put to use. That’s all I’ll say on that for now.
I’m also starting work on the next project. It’s not super-secret. I just want to have gotten a little further before I show it and why not have a little surprise. I’m thinking it’ll be ready to show in a few weeks. Now that Kickstarter is over, I’ve got some time on my hands.
The majority of the kitted synths shipped this week, not all, but most. The first one was built this week by someone other than me. I’m glad to see that the build was successful. I love the smell of validation. At the very least, it means that everything is coming out correct. And I couldn’t be happier than that. Built synths start to ship next week. Tomorrow, I’m having a little solder party with some friends to hopefully get close to finishing the Kickstarter orders entirely. I’ve got about 10 finished, and another 10 in some state of finish. Tomorrow, we’ll be taking down a good portion of the last 10.
If you hadn’t read in the forum, the pcb house neglected to cut slots for the DC power jack. This means you’ll have to basically flush cut the tabs and solder it on. I haven’t noticed any mechanical problems with that, but you’ll want to have it close to the board when the case comes together.
On that note, I’ve finished the case design and will be getting samples next week. I’m waiting for my wife to finish jazzing up the engraving to order it. It’s going to be made from black acrylic. I think it’ll be pretty sweet
The journey continues. I’ve put in some good time with the firmware this week and developed some good stuff. I’ve been tweaking wavetable playback to make some dynamic sounds. I’ve made similar changes to the LFO waveshapes that have made those pretty interesting. I’ve tightened up the filter envelope timing and found a handful of little bugs. This work will continue. More waveshape stuff. Tweaks to the pitch shifting. There have been requests for portamento which is just a subcategory of pitch shifting. I’ll try to squeeze it in.
The PCBs are on order. I’m ordering parts pretty soon.
Here’s a little gem I made to tide you over. I’ve got only oscillator 2 on. The LFO is working the Detune, so it’s swinging the pitch. This is one of the new LFO waveshapes. Then, I’m messing with knobs while its running. The bandpass filter is on and it’s perfect for this sorta thing.
In less than half the time I allotted for it, the Kickstarter project reached 100% funding. Thank you to everyone who took the leap to fund this project. I thought it would take longer and actually thought in the beginning that it might not work out at all. In the first few days, I considered the possibility of what I might do with myself if it didn’t pan out. Well, I don’t have to wonder now. I know that I’ll be working on fulfilling all the orders. I really can’t wait to see what all of you end up doing with it when you get it.
In the meantime, I’m wrapping up the pcb layout. I’ll probably stare at it for a few days just to make sure that it’s perfect before I put in an order for a few to build. If all that pans out, which it should as the changes were minor, I’ll begin ordering the boards and parts potentially before the end of the project just to speed things along. No promises there, but I’m going to do my best to get these to you as soon as I can. There’s still the need to develop the case, but I’ve prioritized function over the case for the time being. I’ll get back to it soon.
Thanks again!