Tag: vibration motor

Basic Node for the Internet of Sex Toys – part 2: 3d printed form, assembly, molding

In this series of posts we describe how-to make a vibrating sex toy which is part of the Internet of Things.

part 1: Basic Node for the Internet of Sex Toys

part 2: Molding the Basic Node

part 3: Software for the Basic Node

In part 2 we describe how-to make a mold form for the basic node. We need three forms:

  • the mold form which consists of two parts
  • the inlay which protects the electronics of the basic node
  • a “hanging” for the inlay




We used Tinkercad to construct the parts. The molding form is based on Tinkercad’s banana form. You can edit and share them from your browser:

Inlay: https://tinkercad.com/things/h5fFOBqlmjw

Hanging: https://tinkercad.com/things/jUxc2oAamww

Form: https://tinkercad.com/things/6HS3XScOsCM


Print out all forms. The STL files are available at Thingiverse. You might want to use XTC or similar for smoothing the inner part of the mold form.

Assembling the Inlay

We use the inlay to protect the electronics.

Simply put the electronics inside so that the upper body of the switch is on the same level as the upper inlay. We use hot glue to fix the basic node.

Then fix the receiver coil of the wireless charging module on top of the inlay. The next step is to fix the hanging at the inlay.

Now fix the LiPo battery on the bottom side of the inlay using hot glue or similar. Fix the wires. Finally you might fix the wires of the vibration motor next to the middle of the LiPo battery.

Use tinkering wire to fix both parts of the molding form.

Put the inlay in the form. Fix the hanging with a tape or similar. The motors shouldn’t touch the inner part of the form.

Now prepare the silicone. We use Shore A 45 silicone (approx. 250 ml) from Silikonfabrik.de. It is hard but still a bit flexible. You may add color, too. You have about 10 minutes to stir the silicone and poor it in the form.

After some hours you can remove the form. As you can see there is overhang which make removing the form very hard. The form could break when removing. Better preparation of the form (eg rasping) could improve the results.

If the blue LED of the Wemos board is still active you were successful.

Now you need a charging station. The construction is shown here. It is also possible to connect the sender (or transmitter) module with a 5V power source (eg. from the USB port). Just put the bottom of the molded basic node on the sender coil.


In the next part we introduce an updated version of the software including over the air update and WiFi management.

Internet of (sex) things – part 4: Building a sex toy dashboard with Node-RED

In the fourth part of the tutorial we explain the development of a dashboard for our sex toy.

The series has 4 parts:

part 1: Exploring the internet of (sex) things

part 2: MQTT messages

part 3: Node-RED

part 4: Building a sex toy dashboard with Node-RED

The dashboard is used to visualize certain data eg. the speed of the vibration motor and the movements of the vibrator. In addition it can have some control elements eg. for changing the vibration pattern.


The window above is called a tab. You can have multiple tabs. The Motor, Data, Status and Controls – windows are called groups. The Controls – group has buttons to set the motor mode. In addition there is a slider which will set the motor to a constant speed. And there is an on/off button for the LED.

You have to install the Node-RED dashboard. Therefore you need at least version 0.14 of Node-RED. At the time this text was written the standard Node-RED installation is version 0.13 which is not sufficient for the dashboard.

Therefore check your Node-RED version. If it is equal or better than 0.14, skip this step:

  • Download & unzip the latest version from github (eg. https://github.com/node-red/node-red/releases/tag/0.15.2).
  • Now change to newly created directory eg “node-red-0.15.2”
  • On Windows: Start a command shell in adminstration mode
  • Execute “npm install” to install Node-RED.

If your Node-RED version is 0.14 or better install the dashboard:

Some  remarks:

Let’s start and have a look at the new Node-RED interface: On the left side you will find the dashboard or user interface nodes. And on the right side there is new dashboard – tab. It contains all dashboard nodes which are used in the flow ordered hierarchical.


But where is the dashboard? Just open your browser and go to one of the URLs:

http://localhost:1880/ui/#/0 or

How can I get all the flows? You can download all flows here: bi-ui-node-red. Unzip the file and you will get a text file. Open the text file in an editor. Select the text and copy it to the clipboard.

Now we will explain two flows in detail.

Now go the Node-RED window, open the menu (it is on the left top side), select Import -> Clipboard.import1

A new window will open where you can insert the text (CTRL+V). Then press the Import-button.


nodemcu prototype breadboardThe Arduino sketch was updated for the dashboard. Please download the Arduino sketch from here: iost-part4-v12. Unzip the file. Compile and upload to your hardware (see part 1 of the tutorial).


In the first flow we will receive some vibration motor sex toy data which are sent by the MQTT protocol. We will display the data using a gauge and a graph element.

Let’ start with the MQTT input node. There is nothing new. Just connect to the MQTT server and subscribe the topic “BIoutTopic2” – which the sex toy uses to send out data.mqtt-in

Now add the function node “JSON” which will parse the incoming message and places the result in “payload”.

But we want to know the motor speed only. Therefore we need a function node which passes the vibration motor speed as payload and deletes all other data. Please use the following JavaScript code:


To display the speed we need to more nodes. The gauge node gauge-node displays the actual speed. Connect the gauge node with the function node. You can add the range – the minimum and maximum value (0 and 1023).motor-gauge


Now add a chart node chart-nodeand connect it with the function node, too.


Next we want the chart node and the gauge node to be together as shown in the next image.


We have to make a group and put both nodes into the group. Have a look on the dashboard at the right side. Make a new group and move the gauge and chart node below the group called “Motor”.


slider-nodeNow we explain the second flow. It is used to send commands to the sex toy. We will use a slider to control the speed. But there is one problem: the slider should display the actual speed of the vibration motor. Therefore we manipulate the slider. To display the actual motor speed we have to move the slider appropriate to the actual speed. The slider will be part of the control group:


Now get the slider node and edit the node as follows:


Then connect the node with the “get motor speed” function which was introduced in the first flow.

construct-json-motor-speed-function-nodeFinally comes the trick part. Get a new function node and connect it with the slider. This node will construct the JSON message which will be sent to the sex toy using MQTT. The JavaScript code of the function node is as follows:


msg.payload={messageType:"execute", actuator:"motor1",
             actuatorMode:"constant", actuatorValue:msg.payload}
msg.topic = "BIinTopic";
return msg;

Now connect the function node with a new MQTT output node. Leave the topic empty as it will be passed from the input nodes:


Using Node-RED with the Node-RED dashboard we are able to make a user interface for our sex toy(s). We could easily display the motion of the sex toy as well as the vibration motor speed. You could argue that we had a (very simple) user interface already in part 1 of the tutorial, without having to use MQTT, Node-RED and the Node-RED dashboard. That’s true. But imagine you have several sex toys and want to control them. You could easily add a tab in Node-RED for each sex toy. Or you could build more sophisticated flows incorporating several sex toy. Why not interconnecting the vibrating necklace with a penis ring and one of the plugs or dildos?

There are a lot of flows and nodes already available at http://flows.nodered.org/. (Of course not in the sex toy domain)

Why not play music for a given sex toy vibrator mode? Or control the sex toy using another IOT device…

Exploring the internet of (sex) things 1

The internet of things – or short IOT – is getting popular. IOT is a network of physical things like vehicles, buildings, but also everyday objects like lamps, refrigerators. IOT allows objects to be sensed and controlled remotely across the Internet. As a result the physical world will be integrated into the internet and computer systems.

Popular examples are home axiomatization or collection of environmental data.  Even sex toy industry use the internet to connect sex toy users which are far away of each other (like the OhMiBod blueMotion). The vision of remote sex driven by technology is also known as Teledildonics. Unfortunately I didn’t pay much attention to this movement which goes back to 1975. body interaction focused more on wireless connected sex toys for users having sex together and want to integrate his and her’s sex toy. You will find a lot of information at Kyle Machulis site Metafetish. Also have a look at the annual conference Arse Elektronika which focus on the intersection of technology and sex.

In this blog I have already shown how to connect the body interaction development board to the internet. Now I will present some first steps into IOT. I will use the NodeMCU development board which is based on the popular ESP8266 System on a chip. The ESP is a wi-fi enabled microcontroller where you can connect sensors and actuators. It can connect to your wi-fi access point and home and it can be an access point itself and host eg. an internet server.

In my explorations I will try to find out if a IOT sex toy is useful for DIY sex toy community.

In this blog post we will use the ESP8266 as a wi-fi server. The server will connect to your wi-fi access point at home.

The series has 4 parts:

part 1: Exploring the internet of (sex) things

part 2: MQTT messages

part 3: Node-RED

part 4: Building a sex toy dashboard with Node-RED

Building a bread board prototype

nodemcu prototype breadboard

Material needed

  • bread board, wires
  • Node MCU or similar
  • small vibration motor (or LED), eg the Lilipad vibration motor
  • optional: accelerometer  MPU9265
  • optional: another LED and a resistor

WIre MPU9265


  • SCL (on MPU9265) and D1 (on NodeMCU),
  • SDA and D2,
  • VCC and 3V3
  • GND and GND

Wire vibration motor


  • D7 (node MCU) with vibration motor (+) and
  • GND (NodeMCU) and (-)

Wire LED


  • D3 (NodeMCU) and LED (long end)
  • LED (short end) and resistor
  • resistor and GND (NodeMCU)

Using the Arduino IDE

NodeMCU and all other ESP8266 boards are not supported by Arduino. But you can use the Arduino board manager to add other development boards. This short Tutorial explains the necessary steps: http://www.instructables.com/id/Quick-Start-to-Nodemcu-ESP8266-on-Arduino-IDE/

Connect the NodeMCU to your access point (WLAN router)

Upload script to NodeMCU

Copy the code below to the Arduino IDE or download and unzip this Arduino “.ino” file.

Within the sketch you have to change the constants SSID and password. Use the same SSID as you would do to connect your smart phone or computer to the internet.

Select your NodeMCU and the port. Connect your computer and the NodeMCU with USB wire. Upload the script to NodeMCU

#include <ESP8266WiFi.h>
#include <Wire.h>

#define MPU9250_ADDRESS 0x68
#define MAG_ADDRESS 0x0C

#define GYRO_FULL_SCALE_250_DPS 0x00
#define GYRO_FULL_SCALE_500_DPS 0x08
#define GYRO_FULL_SCALE_1000_DPS 0x10
#define GYRO_FULL_SCALE_2000_DPS 0x18

#define ACC_FULL_SCALE_2_G 0x00
#define ACC_FULL_SCALE_4_G 0x08
#define ACC_FULL_SCALE_8_G 0x10
#define ACC_FULL_SCALE_16_G 0x18

const char* ssid = "????"; // Enter the name of your Access point
const char* password = "????"; //Enter the password SSID
int ledPin = 0; // NodeMCU pad D3 = GPI0
int motorPin= 13; // NodeMCU pad D7 = GPIO 13
double sinusValue=0;

// define constants for four different vibration modes
const int off_mode=0;
const int max_mode =1;
const int sinus_mode =2;
const int motion_mode =3;

int motor_mode =off_mode;

WiFiServer server(80);

 // This function read Nbytes bytes from I2C device at address Address.
// Put read bytes starting at register Register in the Data array.
void I2Cread(uint8_t Address, uint8_t Register, uint8_t Nbytes, uint8_t* Data)
 // Set register address

 // Read Nbytes
 Wire.requestFrom(Address, Nbytes);
 uint8_t index=0;
 while (Wire.available())

// Write a byte (Data) in device (Address) at register (Register)
void I2CwriteByte(uint8_t Address, uint8_t Register, uint8_t Data)
 // Set register address

void setup() {

 // NodeMCU D1 = GPIO5 connected to MCU9265 SCL
 // NodeMCU D2 = GPIO4 connected to MCU9265 SDA

 // Configure gyroscope range
 // Configure accelerometers range
 // Set by pass mode for the magnetometers

 // Request first magnetometer single measurement


 pinMode(ledPin, OUTPUT);
 digitalWrite(ledPin, LOW);

 pinMode(motorPin, OUTPUT);
 analogWrite(motorPin, 0);

 // Connect to WiFi network
 Serial.print("Connecting to ");

 WiFi.begin(ssid, password);

 while (WiFi.status() != WL_CONNECTED) {
 Serial.println("WiFi connected");

 // Start the server
 Serial.println("Server started");

 // Print the IP address
 Serial.print("Use this URL to connect: ");


int16_t ax,ay,az,ax1,ay1,az1,gx,gy,gz,gx1,gy1,gz1;
int valueMotor; //vibrator motor speed 0-1023

void loop() {

 // Read accelerometer and gyroscope
 uint8_t Buf[14];

 // Create 16 bits values from 8 bits data

 // Accelerometer
 ax=-(Buf[0]<<8 | Buf[1]);
 ay=-(Buf[2]<<8 | Buf[3]);
 az=Buf[4]<<8 | Buf[5];

 // Gyroscope
 gx=-(Buf[8]<<8 | Buf[9]);
 gy=-(Buf[10]<<8 | Buf[11]);
 gz=Buf[12]<<8 | Buf[13];  // when in "motion_mode" the vibration motor 
//is controlled by motion  
if (motor_mode==motion_mode) {  
  int v = 0;  
  //calculate motion vector 
  // adjust vibration motor speed  
  // if motion vector > 5000 raise speed by 25
  // otherwise lower speed by 10
  // adjust these constants to your needs
  if (v > 5000) {valueMotor=valueMotor+25;} else {valueMotor=valueMotor-10;}
  //values must be above 500 otherwise the motor is off 
  if (valueMotor<500) {valueMotor=500;} 
  // values higher than 1023 are not supported
  if (valueMotor>1023) {valueMotor=1023;} 
  analogWrite(motorPin, valueMotor); // set motor speed

  Serial.print("v: ");
  Serial.print(", valueMotor: ");

  // save values

 // change vibration motor speed according to a sinus curve
 if (motor_mode==sinus_mode) {
 int sin_tmp = ((sin(sinusValue)+1)*.5*(1023-500))+500;
 analogWrite(motorPin, sin_tmp);

 // Check if a client has connected
 WiFiClient client = server.available();
 if (!client) {

 // Wait until the client sends some data
 Serial.println("new client");

 // Read the first line of the request
 String request = client.readStringUntil('\r');

 // Match the request

 int valueLED = LOW;
 if (request.indexOf("/LED=ON") != -1) {
 digitalWrite(ledPin, HIGH);
 valueLED = HIGH;
 if (request.indexOf("/LED=OFF") != -1) {
 digitalWrite(ledPin, LOW);
 valueLED = LOW;

 if (request.indexOf("/MOTOR=MAX") != -1) {
 analogWrite(motorPin, 1023);
 valueMotor = 1023;
 if (request.indexOf("/MOTOR=OFF") != -1) {
 analogWrite(motorPin, 0);
 valueMotor = 0;

 if (request.indexOf("/MOTOR=SINUS") != -1) {

 if (request.indexOf("/MOTOR=MOTION") != -1) {

 // Return the response
 client.println("HTTP/1.1 200 OK");
 client.println("Content-Type: text/html");
 client.println(""); // do not forget this one
 client.println("<!DOCTYPE HTML>");

 client.print("Led pin is now: ");

 if(valueLED == HIGH) {
 } else {

 client.print("Motor pin is now: ");

 client.println("<a href=\"/LED=ON\"\"><button>Turn On </button></a>");
 client.println("<a href=\"/LED=OFF\"\"><button>Turn Off </button></a>");
 client.println("<a href=\"/MOTOR=MAX\"\"><button>Motor Max </button></a>");
 client.println("<a href=\"/MOTOR=OFF\"\"><button>Motor Off </button></a>");
 client.println("<a href=\"/MOTOR=SINUS\"\"><button>Motor sinus curve </button></a>");
 client.println("<a href=\"/MOTOR=MOTION\"\"><button>Motor motion controlled </button></a>");

 Serial.println("Client disonnected");


Controlling the vibrator prototype

After uploading the script above, open the serial monitor. After some time the NodeMCU will report “wifi connected”.

IOT wifi connectdNow start a browser. Use the URL which the NodeMCU reported eg.

If your smart phone is connected to the same Access point as your computer is, you can use your smart phone to control the prototype, too.

You can turn the LED on or off by pressing the “Turn On” and “Turn Off” buttons.

For controlling the motor you have 4 options

  • motor on
  • motor off
  • sinus curve (the motor will speed up and slow down according to a sinus curve)
  • motion controlled (more motion -> motor speeds up)


To build a vibrator prototype based on the ESP8266 MCU is very easy. You can use your Arduino IDE to upload scripts to the prototype. Then you can control the vibration motor through a browser. If you don’t want to use these external control options the vibrator prototype can be controlled by motion similar to the body interaction vibrator development board.

In this blog post series we will  explore other interesting features of the ESP8266:

  • the ESP8266 as an access point (no need for private or public access points)
  • over the air (OTA) uploading of sketches  (wireless – no USB connector needed)
  • MQTT protocol & server
  • Node-RED (visual IOT programming)
  • review of development boards for building IOT vibrators

Go to the second part of the tutorial.

New vibrator design “fusion”


fusion-quer-look-throughbodyinteraction designed a lot of vibrating toys, some are usable as massage devices, some are explicit sex toys (vibrator ring, balls), some are experimental (collar). Everyone is motion controlled. If you have more than one they will influence each other remotely, eg. a vibrator and a vibrator ring.


But a device like a classic big vibrator is still missing. So we designed the “fusion” which is approx 19cm long and up to 4+cm in diameter. It is called fusion as the case is made of silicone and 3d printed material (ABS).


We have put the body interaction vibrator development board, motor and battery in a silicone form. There is an on/off switch – so when you travel the vibrator doesn’t wake up when it is moved. And you can charge the battery with a USB micro connector. There is a spacious inlay for the electronics, so it will be easy to get it done.


  • easy to charge the battery via USB
  • on/off switch
  • hard handle
  • flexible upper part
  • large (if you like this)
  • ISP interface (“hacker port”) accessible


  • only the silicone part of the form can be put under water for cleaning

What do you need?

  • 200 ml silicone with high shore A rate, eg. shore A 45 from silikonfabrik.de
  • optional: special colour for silicone molding
  • 3d print of the molding form, inlay and closure
  • tinker wire
  • body interaction vibrator development board with LiPo and motor (or similar Arduino boards)
  • bin for preparing the silicone, something to stir the silicone

How much is it?

  • Board, battery, motor: 30$ (buy at Tindie)
  • Silicone: 10$
  • 3d Prints: less than 5$

Step by step instructions

Step 1: Print out the inlay, the form and the enclosure


Download as zip-file: Fusion

Download at Thingiverse: http://www.thingiverse.com/thing:1505539

Step 2: Prepare the inlay: Insert the body interaction board and the LiPo battery

The body interaction vibrator development board is inserted into the provided rails. It it doesn’t fit in use a file to remove printing artefacts. Use some glue to fix the board. Then insert the battery and fix it.

Important: The Micro USB connector must be above the upper part of the inlay.

inlay with description

Step 3: fix the wires of the vibration motor

The vibration motor will hang down from the inlay as the inlay will be put in the form upside down. You can influence the position of the motor by shortening the wire or fixing the wire to e.g. to the battery. In this case the wire of the motor was threaded between battery and board. Therefore the  motor will be in the middle of the vibrator.

inlay-inner-partfusion-looking-through-2in the center there is the overmolded vibration motor

Step 5: Prepare the form

Use some tinker wire to “press” both parts of the form tight together.molding-form-emptyUse some wax to fix little holes in the form where the printer failed. (These are the white spots)


Step 6: Insert inlay into the form

There must be some space between inlay and form for the silicone.

Remark: The two wedge like forms at both sides of the inlay help to hold the inlay. The wedge can be removed after molding.inlay-in-molding-form

Step 7: Cast the silicone

Prepare the silicone as the producer recommends. It takes some time to pour the large amount of silicone into the narrow form. The silicone we use must be used within 10 minutes. So start at once after preparing the silicone.

Important: The USB micro connector, the switch and the ISP connector shouldn’t be dashed with silicone. If this happens remove the silicone. Maybe some silicone will remain behind. This can be removed later when the silicone is solid.molded

The battery is covered with silicone, the USB connecor and switch are not.drying-seen-from-top

Step 8: Remove the form

Remove the tinker wire. Remove overhanging part of the silicone. Carefully tear both parts of the form away. You can use a knife, but be careful not to “hurt” the vibrator. Remove overhanging silicone at the vibrator. Also remove the two wedge like forms at both sides of the inlay.

unboxing-fusionfusion looking through complete

Step 9: Install the closure

Now you can put the closure on the inlay. Fix the closure with glue. (Be careful! The USB connector is not very strong.) closed-inlayround_something_055_final_cap_onlyfusion-closure

Tinker, share and download from Tinkercad:

form and inlay: https://tinkercad.com/things/b8nQxRn4XWl

closure: https://tinkercad.com/things/dhgtgeaYG0B

Download as zip-file: Fusion

Download at Thingiverse:



New fusion 3d printed and silicone molded vibrator

fusion tinkercadThis is the initial design. The round curved form will be in silicone with vibration motor within (vibration motor not shown on sketch). The red part is 3d printed. It is the enclosure for the body interaction vibrator development board and LiPo battery. You can plug-in the Micro USB connector for battery charging. In addition there is an on/off switch e.g. for travelling.

Silicone overmolded vibrator – balls revisited

molded-quermolded-with-ueberh-querBuilding your own silicone molded vibrator becomes now easier. We already have presented 3d printed forms for building your personal vibrator (massage wand, wireless charged vibrator). The vibrator uses the body interaction vibrator development board. The body interaction board has a Arduino compatible microcontroller, vibration strength control by motion, a vibration motor and a rechargeable battery.


balls_revisited_3_inlay_part_bWhat is new? The electronics including battery are in the base of the vibrator. We developed a 3d printed enclosure for the electronics. This has several benefits: The assembling of the electronics and the molding itself is easier as everything is fixed within the enclosure. And it is more safe as the enclosure shields the electronics from the environment (and vice versa). In addition we used a different charging module from Seeed Studio. The input voltage is only 5V. Now you can connect the charging module with a USB connector and don’t need another power supply. (Look here for an explanation of wireless charging sender and receiver.)


Another improvement is the placing of the vibration motor. The vibration motor can now be placed in the center of the vibrator and it different heights. Just were you need the power.

balls_revisited_3_inlay_part_aFinally the mounting is improved. The mounting holds the enclosure when it is inserted into the form.

balls_revisited_3_finalThe mounting (together with the enclosure with the electronics) is inserted into the form. The form consists of two parts which must be fastened together by tinker wire. It is a variation of the ball theme.

We present a step by step procedure for tinkering the vibrator. You need:

  • 3d printed form (molding form, 2 parts)
  • 3d printed enclosure
  • 3d printed mounting
  • body interaction vibrator development board
  • silicone with a high shore A value (eg. shore A 45 which is quiet hard but still flexible), approx. 100 ml
  • wireless charging module eg. from Seeed studio
  • soldering station, (hot) glue

Step by step procedure:

A. Print out all forms. You can download the forms from Thingiverse.


B. Connect the wireless charging module to the body interaction vibrator development board.

B.1 You have to solder a wire connecting (-) on the wireless charging module and GND on the body interaction board.

B.2 Now comes the tricky part. You have to connect (+) from the charging module with the body interaction board. Solder a wire at (+) of the charging module. But where do you solder the wire on the body interaction board? Unfortunately the wireless charging option was not taken into consideration during the development of the board. So there is no appropriate connection on the board.

circuitThe best solution is to unsolder the USB connector and connect to + of the USB connection. The easiest way to unsolder the surface mounted USB connector is done with a hot air soldering station.  Alternatively you can solder the wire directly to the MAX1555 module – this solution is presented here. In any case: Be careful not to break the tiny pads connecting pcb and USB connector.

B.3 Connect the sender module with a 5V power supply. You can use a USB cable, dismantle the cable and connect the black and red wires.


C. Place the receiver charging coil on top of the enclosure. The diameter of the top side is a bit larger than the diameter of the bottom side. Use some glue to fix the coil. Don’t fix the mounting now. It is easier to do it later (step E).


D. Put the electronics into the enclosure: Begin with the body interaction board. The RFM12b is quite large so place it at an outer position. Then insert carefully the LiPo battery. Don’t force it! The plugs for the battery and the motor could break. If you have done so insert the tiny wireless charging receiver board. At the end fix the wires of the vibration motor in the middle of the enclosure.

E. Connect the mounting with the enclosure. There are 2 holes provided where the mounting fits into the enclosure. Use some glue to stick together both parts. (see picture above step C).



F. Put together both parts of the molding form. Use tinkering wire to attach both parts tight together. Then insert the enclosure into the form. Check the wireless charging function. The yellow LED must be on when you place the charging coil over the receiver coil.


G. Now poor silicone into the molding. We use Shore A 45 silicone which is rather hard. The silicone has to dry for some hours or days. Read the instructions of your silicone provider.


H. When the silicone is hard, you can remove the tinkering wire. Then carefully remove the form.


I. Remove the overhang.


J. Test the wireless charging. The orange LED must be on when both coils are near together.

molded-bottom IMG_20160303_184830

K. Remove the mounting.


Design your own forms using Tinkercad. Start now and share!

Old versions of the enclosure:Enclosure & mounting togther, Enclosure , Mounting

Download the STL files for 3d printing from Thingiverse.

Update 2016/03/12: Added image of circuits showing where to solder the wireless charging module.

Update 2016/04/05 redesign of mounting and enclosure due to different versions of the wireless charging receiver coil

Programming Tutorial part 4: Sinus

Nervous Optic by Ben Felten, CC BY-ND 2.0

Nervous Optic by Ben Felten, CC BY-ND 2.0

In tutorial 3 – “ramps” we learned how to repeat instructions again and again using the for statement. In this tutorial we need the for loop again, bur instead of changing the motor speed by a constant value we want a more dynamic behavior. Therefore we use the sinus function – a classical pattern used for controlling vibrators.

Here is a straight forward approach:

for (float i = 0; i < 20000; i = i + 0.05) {
  analogWrite(motor, (sin(i)); //motor speed set to sin(i) 

We are changing the variable i in small steps of 0.05. So the variable i will become 0, 0.05, 0.1, 0.15, 0,2 … and so on.

But this doesn’t work. Let’s have a look at the sinus function. Just use the google search and type in “sin(x)”. You will see  the following curve:

sin(x) in google

There are two problems:

  • There are values below 0 (on the vertical or y-axis). If the value is 0 or below 0 the motor is off.
  • The maximal value is 1. But  we need values between the minimal motor speed (around 40) and the maximal speed (always 255).

You can try to adjust the function and visualize it with google search. Maybe you will discover an interesting variant of the sinus curve.

We use the following function:

(sin(x)+1) 0.5 * (maximal motor speed – minimal motor speed)) + minimal motor speed

  • Sin(x)+1: add 1 to get positive values only between 0 and 2 instead of -1 and 1.
  • Multiply by 0.5: get values between 0 an 1 instead 0 and 2
  • Multiply with maximal motor speed  (255) – minimal motor speed (40): values are now between 0 and 215
  • Add minimal speed: values are between 40 and 255. So the motor will always be on.



This is the script. Please have a look at tutorial 2 if you don’t know how to upload the script.

 // www.bodyinteraction.com tutorial sinus 
int motor = 3; 
int minimal_motorspeed = 50; 

void setup() { 
  pinMode(motor, OUTPUT); 
void loop() { 
  for (float i = 0; i < 20000; i = i + 0.05) { 
    analogWrite(motor, ((sin(i) + 1) * 0.5 * 215) + 40); 

If you want to slow down the changes in the motor speed change delay(5) and take larger values.

Go back to tutorial 3: ramps

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