From GreyMatter
Jump to: navigation, search
Seems legit


EDGE-209 is a biofeedback device designed to hold a person as close as possible to orgasm without actually reaching orgasm. This practice is generally known as edging.

The project was previously known as Project Neurokink and focused solely on consumer-grade EEG brain activity sensors, but the name was changed after it became apparent that no single sensor was going to be able to provide data of usable quality.

High-level diagram

In one end, out the other.


Photo Type Manufacturer Model Notes
Polar T34 Education Kit.jpg Heart rate Polar T34 Educational Kit A reliable wireless heart rate monitor designed to be fitted as a chest strap.

Advantages over an optical sensor include higher sensor accuracy, prebuilt wireless communications with a pulse-per-beat output on the receiver board, and resilience to movement by the subject.

Unfortunately the battery is not user-replaceable, though it is rated for 2,500 hours of operation.

Myndplay headset.jpg EEG MyndPlay MyndBand BLE Any modern NeuroSky-based headset is a solid option here.

The MyndBand BLE is designed for comfort and is less obtrusive than the MindWave Mobile - meaning it'll be easier to integrate with hoods and other gear.

MyoWare Muscle Sensor.jpg EMG MyoWare Muscle Sensor Pads can be given further reach using the MyoWare Cable Shield.

Placement for monitoring pelvic floor muscle contractions needs further research. These muscles tense and pulse involuntarily as orgasm approaches.

Alternative monitoring might be possible using a buttplug and testing for compression, as the pelvic floor contractions tighten the sphincter.

Custom build.jpg Plethysmography (internal) Homebrew E209-SPLE-INT Internal plethysmograph, as insertable.

Detects contractions and internal volume changes.

May include internal optical skin flush sensor.

Custom build.jpg Plethysmography (external) Homebrew E209-SPLE-EXT External plethysmograph, as sleeve.

Detects erectile response and contractions.

May include testicular retraction sensor.

Custom build.jpg Skin flush Homebrew E209-SSFL Clip-on or self-adhesive skin flush sensor.

Detects vascular changes in sampled tissue.

Custom build.jpg GSR Homebrew E209-SGSR Clip-on or self-adhesive galvanic skin response sensor.

Detects emotional changes through sweat gland activity.

Biological response envelope presents a very fast attack, but relatively slow decay.


Input aggregator


Responsible for sampling the various sensors and outputting a frame at least once per input sample rate tick.

Tuples (containing sensor identifier, raw sensor value, and normalised signed-int8 sensor value) will be grouped as possible without violating the maximum time between samples (as determined by the input sample rate).

As such, a frame will contain between 1 and [number of sensors] records. A frame will also contain a UNIX timestamp as a float with enough precision to allow for milliseconds. It may also contain debugging information.

Frames are sent via MQTT, over IP, to the core logic.


Since the IA will deal with heterogenous input protocols, including raw pulse-per-event, realtime is very important. However, since the IA will also deal with high-level protocols like Bluetooth LE, a basic MCU is unlikely to be sufficient.

The ESP32 seems a good fit. More than capable of the sample rates needed, it offers plenty of GPIO and wire protocols, as well as integrated 802.11 and Bluetooth (vanilla and LE) stacks. The core clock can run at up to 240MHz, which is more than sufficient.

It is also Arduino-compatible for rapid prototyping.

Core logic





Output controller