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If you've been reading my latest blogposts or if you know me personally, you'd have known that the so-called "Toy Motor Controller" had been dead since last year. This blogpost describes what exactly had happened and how it died.
All of the previous official blogposts made for this project was just smoke and mirror. The true nature of this so-called "Toy Motor Controller" is that, it's an edging machine sex toy. It's meant to bring someone close to orgasm without ever reaching it. I made it for my own use and hope that I can sell it for cheap so that people can enjoy this technology.
I was thinking of purchasing an edging machine. There is a design available for sales in the market. Unfortunately, it's way too expensive ($400) that I decided to make a clone because I could use the same $400 as the budget for the entire project. I thought that it'd be easy because firmware was open source. After working on it for a few months, I found that my clone wasn't working and I started asking around on the internet and I was shocked to find that the design I was trying to clone didn't work consistently across all people. In fact, most people found it not working.
Then I spent like another 3 years on trying on figuring out an algorithm to make it work, with some of the time sidetracked on maintaining the smoke and mirror by implementing irrelevant feature. While I managed to make some progress on the algorithm and setup, I never got it working fully. I've finally given up last year.
As it's a hobbyist project, I'm not here for the hustle. I'm not gonna ever sell a non-working product. I'd rather to let this project die. So be it.
I've actually made a hardware revision 4 that I haven't made a blogpost about, which's the final prototype. Compared with revision 3, revision 4 has 10 buttons instead of two knobs and two buttons. I've also used off-the-shelf key caps instead of 3D printing ones.
This design change was made mainly because edging requires fast response time. I found that it's quicker to press buttons than to press the giant knobs. Plus, cheap buttons have better long term reliability than cheap knobs. Don't ask me how I found out.
The arousal sensor mainly measures either the size of the prostate and the girth of the cock. I've tried the following five designs (from left to right, off-the-shelf inflatable buttplug, analog tube-coil buttplug, electronic tube-coil buttplug, tube-coil cock side ring, resistive cock side ring):
I started off with an off-the-shelf inflatable buttplug with a pneumatic tee that fed into the pressure sensor on my device, which's the same design as the device that I was trying to clone. It gave terrible signal. Someone in an edging machine community figured out the same and designed an analog tube-coil buttplug, which's quite a bit better because the signal gets amplified by the coil. But the problem was that moving hips and breathing would affect the reading of the buttplug. Then I made an electronic tube-coil buttplug, which gives even better signal due to even shorter tubing but still helpless against noise introduced by hip movement and breathing. That's when I designed a tube-coil cock side ring installed onto the base of my cock. The cock side sensor does mitigate the signal noise of breathing. But I still couldn't find a good-enough algorithm for that. Finally I briefly tested with resistive cock side ring (with resistive pressure strip instead of pneumatic tubing) and eventually gave up. I don't have enough data on resistive cock side ring to determine on if it's better than the tube-coil cock ring sensor.
None of them led me to a functional edging machine.
My device can output a strength signal to the vibrator based on the arousal detected. At first I used off-the-shelf vibrators. Some of them are meant to be mounted onto my cock but those are not good enough because the exact spot of stimulation shifts during the long edging session, which causes the change of amount of stimulation even if the same vibration strength got applied. Then I tried wrapping my cock with a thin onahole and use my hand to mount a vibe onto my onahole-wrapped cock, which introduce another problem because how tight I'm holding the vibe would have an effect on the amount of stimulation generated. Finally I 3D printed an Hitachi magic wand-compatible device with a R-555 vibration motor, with off-the-shelf adapter for mounting the wand onto my own cock. The problem was that it isn't hand-free and I still had to hold the wand with my own hand, which's an undesirable variable on the amount of stimulation given.
Again, none of them led me to a functional edging machine.
At first, I didn't know that there weren't any working algorithm and I ported the existing algorithm I found online to my firmware written in C.
After realizing that I had to come up with a new algorithm, I brought up the UART interface of the microcontroller and connected it to my computer. And my computer would run a Python script, which's easier for prototyping than C. That script would read the sensor and control the strength of the vibrator and also perform datalogging. The Python script shows the sensor reading by printing to the CLI console. It also reads the button press of gamepad attached to the computer for controlling the vibe and switching sensitivity and mode and alike. I revised the script many many times.
At later stage of the project, for better visualization and ease of control, I upgraded the Python script that it runs a webserver, which provides a few sliders, a few buttons and a real time graph of the sensor readings. I used the web interface on my phone. Below is the mock up of the webpage in my diary entry back in 2025-05-12 (written in Sadalian):
And here's the actual web interface:
Yet again, none of them led me to a functional edging machine.
After recording and analyzing data for 80 sessions over 3 years, I managed to make some... progress? It isn't exactly consistent but the later sessions do have better result than the older sessions. Unfortunately, it's still not good enough. The best algorithm and setup I've got can get me to the edge like for maybe 30 times but eventually I'd get overstimulated and just cum. And it isn't working quite consistently either.
I consider myself as a good problem-solver. I often manage to revise and improve algorithm I found all around the internet. Unfortunately, this one is a difficult problem. I have no idea on how much more time I'd need to invest to solve this problem. There's no guarantee that a working solution even exist either. So I decided to give up.
Another user of the edging machine community had verified my finding that cock-side sensor has better sensitivity than butt-side sensor. He claimed that he might have figured out a working design for edging machine. Instead of using vibrator tho, he's using e-stim for stimulation, and he used some kind of magnetic sensor for sensing the cock girth for figuring the arousal level. The e-stim strength is based on the calculated arousal level. His algorithm of arousal detection is similar to what I've been exploring. No neural network, no PID control, just some simple algorithm. The good thing about e-stim is that it's hands-free so the physically stimulation can be fully machine-controlled with no variance introduced by the hands.
However, I'm not gonna test this one out for now. I've got better projects to do that'd keep me occupied for at least a couple of years. And yes, since I've abandoned this project, I've successfully completed the ilo nena keyboard, and I'm working on a game console right now which's on track for completion by the end of this year, and I've got two more other projects lined up. After I finished all these projects tho, maybe I could try verifying this e-stim design and make a cheaper version by then. Or perhaps I could just make an orgasm-ruining device instead of an edging machine, which's pretty much a solved problem even without e-stim.
Let's hope that someone would figure out a working setup sooner rather than later. Quite a few people are interested in using that as evidenced by the amount of sales of the "non-working design" that I was trying to clone (at least not working to me. YMMY). To me, it isn't about the profit. It's about letting the users to enjoy the tech. Fuck profit extraction! Fuck capitalism!
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