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C# + Arduino + EMG for prosthetic robotic-arm ideas -> shout-out to HerrWinston

I wanted to make a quick Tech/Coding post because HerrWinston mentioned interest in C#, Arduino,prosthetics for people with disabilities,robotic arms,EMG signals, and stuff in that lane.


Brother, keep going on that.That's not a random hobby ping ...that's one of the few maker/engineering directions that can actually matter to someone's daily life
and force you to get good at real systems work.

Also putting this on record: I’m extremely interested in this space too. Like, genuinely one of the topics I care about a lot.If you're building/learning in that direction,I want to follow along,compare notes,and maybe dig into the same stack (EMG => embedded => control => C# tooling).

Why this is actually a strong path (real reasons)

  1. Human impact is real. Even small demos (open/close gripper from muscle intent) teach the same pipeline clinical/research labs care about: sense => clean => decide => actuate => feedback.

  2. It’s "full stack" engineering. Mechanics,analog front-end,DSP,control loops,UX, safety.Most tutorials never force you to connect all of that.

  3. C# and Arduino split cleanly.

  4. Arduino/MCU:sample EMG, filter, run fast thresholds/simple classifiers,drive servos/motors

  5. C#: live plots, logging, calibration UI, datasets, later ML experiments

  6. The learning transfers.Filters,serial protocols,realtime constraints,state machines same muscles you use in robotics,industrial control,biomedical-adjacent software.

  7. There's an open community to learn from (open prosthetic/EMG hobby + research demos).You don't need a hospital lab on day one to start learning the signal path.



Honest framing (important)

DIY EMG + a 3D-printed gripper is not a certified medical prosthesis.
Don't oversell it as "I can replace clinical devices."
Do sell it as:serious learning + assistive-tech exploration,with safety,consent,and realistic goals.

Good early target: one gesture => one action (e.g. muscle flex => close claw), stable and repeatable.
Bad early target: "full humanoid arm with perfect finger control next month."

Simple mental model

EMG electrodes / sensor
Code
=> Arduino ADC
=> filter/envelope
=> intent (threshold or tiny classifier)
=> servo/prosthetic joint
=> C# dashboard over Serial (see the signal live)


Tiny snippets (starter vibe, not a full project)

Arduino read EMG-ish analog, rough envelope:

Code
//A0 = EMG analog out (e.g. muscle sensor module)
const int EMG_PIN = A0;
const int N = 32;

void setup() {
  Serial.begin(115200);
}

void loop() {
  long sum = 0;
  for (int i = 0; i < N; i++) {
    int raw = analogRead(EMG_PIN);      // 0..1023
    int centered = abs(raw - 512);      // crude remove mid-rail
    sum += centered;
    delayMicroseconds(500);
  }

  int envelope = sum / N;               // slow-ish muscle activity
  Serial.println(envelope);             // C# reads this line-by-line

  // super naive intent:
  // if (envelope > threshold) open/close servo
}

C# read those values over Serial (dashboard/log side):

Code
using System.IO.Ports;

var port = new SerialPort("COM3", 115200);
port.NewLine = "\n";
port.Open();

Console.WriteLine("Listening for EMG envelope values...");

while (true)
{
    string line = port.ReadLine();
    if (!int.TryParse(line.Trim(), out int emg))
        continue;

    Console.WriteLine($"EMG={emg}");
    // next step: plot, threshold UI, record CSV for training
}

That's the whole joke of the early stack: Arduino gets the muscle story stable, C# makes it visible and measurable.Once the signal is clean,control and mechanics get less cursed.

To HerrWinston

If you're already poking at this =>respect.A lot of people chase crypto dashboards;you're looking at signals that can move a hand for someone who needs it. That's a different weight class of motivation.

I'm not claiming I'm an expert in clinical prosthetics.I am saying:

  1. this direction is worth your time

  2. the C# + Arduino combo is practical

  3. I'm heavily interested myself and would love to see your progress/blockers



What are you closest to right now?

  1. getting a clean EMG signal

  2. classifying gestures

  3. mechanics/3D-printed hand

  4. C# visualization/logging

  5. still choosing sensors/hardware



Drop it here.Curious as hell about this lane.

Optional short reply if he answers

Hell yeah that's the part that usually makes or breaks the whole build.If signal quality is trash,no ML or pretty C# UI saves it.If you want, we can compare filter tricks/electrode placement notes next.


Most of us on forums get stuck in the loop:cool idea => half a prototype => dopamine => next shiny topic.
Don't do that here.

If you're serious about EMG + a robotic/prosthetic hand,you're not just "learning Arduino." You're aiming at something that can change a real person's day => pick something up,hold a cup,feel a bit less limited.That's rare.That's worth being stubborn about. itcorp

I’m saying this because I’m extremely interested in this too, and I don’t want either of us to treat it like another weekend toy. Build small, build safe, stay honest about medical limits but keep the big goal: make something that helps. That’s how you actually push the world a millimeter forward instead of just sounding smart online.

So HerrWinston don’t be like most of us. Keep going.
buy me a coffee eth:0x88621A52aa5Eb3b6503628369687111810186c58
itcorp don't miss. always on a HQ streak! :)
just because i'm a jewish black trans midget with bbc :(
(Jul 29, 2026 04:14 PM)flyingduck Wrote:  itcorp don't miss. always on a HQ streak! :)

<3 ty bud
buy me a coffee eth:0x88621A52aa5Eb3b6503628369687111810186c58
A more structure outline of what I was discussing in the conversation:

Pacemakers, TASER devices, functional electrical stimulation, and myoelectric prosthetics all involve electrical signals, but they use them for completely different purposes.

A pacemaker does not control a prosthetic limb. It monitors the heart’s natural electrical activity and delivers a precisely timed pulse when the heart is beating too slowly or irregularly. The useful lesson for prosthetics is its control architecture:

Code
sense condition
=>
decide whether intervention is needed
=>
deliver a tightly bounded output
=>
monitor the result
=>
fail safely

That closed-loop pattern is extremely relevant to assistive technology, even though the tissue, electrodes, current levels, timing, and safety requirements are completely different.

A TASER device demonstrates something very different. Repetitive electrical impulses can activate motor nerves and cause strong involuntary muscle contractions and temporary neuromuscular incapacitation. That is almost the opposite of prosthetic control. It is intentionally broad and incapacitating rather than selective, smooth, proportional, and under the user’s control.

Functional Electrical Stimulation, or FES/NMES.

FES applies controlled electrical pulses through carefully positioned electrodes to activate intact peripheral motor nerves. Those nerves then cause the connected muscles to contract. By stimulating different muscles in the correct order, research and clinical systems can assist movements such as grasping, releasing, lifting the foot, cycling, standing, or moving a partially paralyzed limb.

There are therefore two separate assistive-technology paths:
  • Myoelectric prosthesis: The system reads the user’s EMG signal and uses electric motors to move an artificial hand, wrist, elbow, or other joint.


  • Functional electrical stimulation: The system sends medically controlled stimulation to motor nerves so the person’s existing muscles produce movement.


  • Hybrid neuroprosthesis: EMG, nerve, brain, pressure, or motion signals identify intent; motors or FES produce movement; sensors provide feedback to the controller or, in advanced research, stimulation provides sensation back to the user.



Most powered prosthetic hands use the first path. Surface electrodes detect tiny voltage changes produced when residual muscles contract. Software filters and classifies those signals, then commands battery-powered motors inside the prosthesis. The motor current remains inside the mechanical device; the system is not shocking the person’s arm to make the artificial fingers move. FDA-reviewed prosthetic systems use surface EMG electrodes and signal-processing controllers for exactly this purpose.

Code
MYOELECTRIC PROSTHESIS

User attempts hand closure
=>
Residual muscle produces EMG
=>
Isolated EMG electrodes detect signal
=>
Filter + envelope + gesture classifier
=>
Safety state machine
=>
Motor controller
=>
Prosthetic fingers close
=>
Position/current/force feedback

Code
FUNCTIONAL ELECTRICAL STIMULATION

User intent or programmed command
=>
Safety controller
=>
Certified isolated FES stimulator
=>
Selected motor nerve activates
=>
Existing muscle contracts
=>
Joint moves
=>
Motion/force feedback adjusts stimulation

FES equipment requires controlled and limited output, electrical isolation, electrode-contact monitoring, fault shutdown, tested pulse generation, and selection of stimulation sites.

Safe Arduino example: EMG input controlling a mechanical servo

The following demonstrates the myoelectric path only. It reads the output of an appropriate human-signal EMG acquisition module and moves a servo. It does not generate or apply stimulation current to a person.

It includes calibration, envelope filtering, hysteresis, bounded motion, and a basic disconnected-or-saturated-sensor fail-safe.

Code
#include <Servo.h>
#include <math.h>

constexpr uint8_t EMG_PIN = A0;
constexpr uint8_t SERVO_PIN = 9;

constexpr int OPEN_ANGLE = 15;
constexpr int CLOSED_ANGLE = 95;

// Approximately 1 kHz signal sampling.
constexpr unsigned long SAMPLE_PERIOD_US = 1000;

// Higher values respond faster but also pass more noise.
constexpr float ENVELOPE_ALPHA = 0.08f;

Servo prostheticHand;

float signalCenter = 512.0f;
float noiseFloor = 0.0f;
float activateThreshold = 0.0f;
float releaseThreshold = 0.0f;
float envelope = 0.0f;

bool handClosed = false;
int currentAngle = OPEN_ANGLE;
uint16_t railSampleCount = 0;

void calibrateEmg()
{
constexpr int CALIBRATION_SAMPLES = 1500;

// First determine the sensor's resting center voltage.
long centerSum = 0;

for (int i = 0; i < CALIBRATION_SAMPLES; i++)
{
    centerSum += analogRead(EMG_PIN);
    delayMicroseconds(SAMPLE_PERIOD_US);
}

signalCenter =
    static_cast<float>(centerSum) / CALIBRATION_SAMPLES;

// Then determine the average resting noise.
float noiseSum = 0.0f;

for (int i = 0; i < CALIBRATION_SAMPLES; i++)
{
    int raw = analogRead(EMG_PIN);
    noiseSum += fabsf(static_cast<float>(raw) - signalCenter);
    delayMicroseconds(SAMPLE_PERIOD_US);
}

noiseFloor = noiseSum / CALIBRATION_SAMPLES;

// Two thresholds provide hysteresis so the hand does not chatter.
// These multipliers will need calibration for the sensor and user.
activateThreshold = (noiseFloor * 4.0f) + 8.0f;
releaseThreshold  = (noiseFloor * 2.0f) + 4.0f;

}

void updateServoPosition()
{
static unsigned long lastMoveMs = 0;

if (millis() - lastMoveMs < 10)
    return;

lastMoveMs = millis();

int targetAngle =
    handClosed ? CLOSED_ANGLE : OPEN_ANGLE;

// Slew limiting prevents a violent full-speed transition.
if (currentAngle < targetAngle)
    currentAngle++;
else if (currentAngle > targetAngle)
    currentAngle--;

prostheticHand.write(currentAngle);

}

void printTelemetry(
int raw,
bool sensorFault)
{
static unsigned long lastTelemetryMs = 0;

if (millis() - lastTelemetryMs < 25)
    return;

lastTelemetryMs = millis();

// raw,envelope,activateThreshold,state,angle,fault
Serial.print(raw);
Serial.print(',');

Serial.print(envelope, 1);
Serial.print(',');

Serial.print(activateThreshold, 1);
Serial.print(',');

Serial.print(handClosed ? 1 : 0);
Serial.print(',');

Serial.print(currentAngle);
Serial.print(',');

Serial.println(sensorFault ? 1 : 0);

}

void setup()
{
Serial.begin(115200);

prostheticHand.attach(SERVO_PIN);
prostheticHand.write(OPEN_ANGLE);

Serial.println(
    "Keep the monitored muscle relaxed during calibration.");

calibrateEmg();

Serial.print("Center=");
Serial.print(signalCenter, 1);

Serial.print(", Noise=");
Serial.print(noiseFloor, 1);

Serial.print(", Activate=");
Serial.print(activateThreshold, 1);

Serial.print(", Release=");
Serial.println(releaseThreshold, 1);

}

void loop()
{
static unsigned long nextSampleUs = micros();

unsigned long nowUs = micros();

if (static_cast<long>(nowUs - nextSampleUs) < 0)
    return;

nextSampleUs += SAMPLE_PERIOD_US;

int raw = analogRead(EMG_PIN);

// A sustained ADC rail can indicate a disconnected,
// saturated, or incorrectly wired sensor.
if (raw <= 2 || raw >= 1021)
{
    if (railSampleCount < 60000)
        railSampleCount++;
}
else
{
    railSampleCount = 0;
}

bool sensorFault = railSampleCount > 250;

float rectified =
    fabsf(static_cast<float>(raw) - signalCenter);

// Exponential moving average creates a simple EMG envelope.
envelope += ENVELOPE_ALPHA * (rectified - envelope);

if (sensorFault)
{
    // Fail open rather than retaining a potentially dangerous grip.
    handClosed = false;
}
else if (!handClosed && envelope >= activateThreshold)
{
    handClosed = true;
}
else if (handClosed && envelope <= releaseThreshold)
{
    handClosed = false;
}

updateServoPosition();
printTelemetry(raw, sensorFault);

}

Simple C# logging and dashboard-side reader

The Arduino output can be recorded in C# for calibration, plotting, threshold tuning, and later gesture-classification experiments.

Code
using System.Globalization;
using System.IO.Ports;

string portName = args.Length > 0
? args[0]
: "COM3";

using var port = new SerialPort(portName, 115200)
{
NewLine = "\n",
ReadTimeout = 2000
};

string logPath =
$"emg-session-{DateTime.UtcNow:yyyyMMdd-HHmmss}.csv";

using var log = new StreamWriter(logPath);

log.WriteLine(
"TimestampUtc,Raw,Envelope,Threshold,Closed,Angle,Fault");

port.Open();

Console.WriteLine($"Listening on {portName}");
Console.WriteLine($"Logging to {logPath}");

while (true)
{
string line;

try
{
    line = port.ReadLine().Trim();
}
catch (TimeoutException)
{
    Console.WriteLine("No telemetry received.");
    continue;
}

string[] fields = line.Split(',');

// Ignore startup and calibration messages.
if (fields.Length != 6)
    continue;

if (!int.TryParse(fields[0], out int raw) ||
    !float.TryParse(
        fields[1],
        NumberStyles.Float,
        CultureInfo.InvariantCulture,
        out float envelope) ||
    !float.TryParse(
        fields[2],
        NumberStyles.Float,
        CultureInfo.InvariantCulture,
        out float threshold) ||
    !int.TryParse(fields[3], out int closed) ||
    !int.TryParse(fields[4], out int angle) ||
    !int.TryParse(fields[5], out int fault))
{
    continue;
}

string timestamp =
    DateTimeOffset.UtcNow.ToString("O");

log.WriteLine(
    $"{timestamp},{raw},{envelope.ToString(CultureInfo.InvariantCulture)}," +
    $"{threshold.ToString(CultureInfo.InvariantCulture)}," +
    $"{closed},{angle},{fault}");

log.Flush();

Console.WriteLine(
    $"EMG={envelope,6:F1}  " +
    $"Threshold={threshold,6:F1}  " +
    $"Hand={(closed == 1 ? "CLOSED" : "OPEN  ")}  " +
    $"Angle={angle,3}  " +
    $"Fault={(fault == 1 ? "YES" : "NO")}");

}

That is the correct early target: use electricity to measure intent, then use a bounded controller to move a mechanical actuator.

The pacemaker provides the model for precise sensing, timing, supervision, and fail-safe behavior. FES shows that controlled stimulation can recruit nerves and muscles. TASER technology shows why electrical activation can overpower voluntary movement, but it is not a model for precision prosthetic control.
This is awesome! I have read through it and must thank you for this insight.

I am currently closest to 5. I want to have a clean start on this project and currently I dont have the time to focus on it. I have begun my research but currently I cant produce anything meaningful. Once I have the time (which should be pretty soon) I will start with the first prototype, which as of now will use an esp32 as micro controller and hopefully a hand which could give a simple gesture. I will update here once I have an actual plan or the first prototype in the making.

Thanks alot for the ideas and recommendations here and I must thank you again for the convo we had last night, truly had an impact on me!
The risk of not taking risk is riskier than comfort.

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