freePEMF user manual

Front panel

  This freePEMF page is a free and open-source material decribing the PEMF low-frequency pulsed electromagnetic field therapy device. It has been designed for people who don't necessairly have the electronic background and could put it together by themselves. Amongs other sources, this device has been based on A. Meyers book "PEMF - The Fifth Element of Health". More articles on this and similar topics can be found at page

Device parameters:

  • Output frequency: 0.01 - 60 Hz; Software version mini-freePEMF 2018-10-28 and newer: 61Hz - 16kHz ***
  • Communication socket with PC: miniUSB;
  • FLASH memory for user's therapy script: 1000 bytes:
  • Polarity change: yes - realized with a relay every 2 minutes. Software controlled;
  • Minimum output load resistance: 6 ohms. Output current: 2 A;
  • RMS magnetic induction and impulse: adjustable by coil selection;
  • 14 V power supply;
  • Working time with 50 ohms load: about 3 hours;
  • Signal type: square, default 50/50% fill, program controlled 1-99%

(***) Frequencies above 60Hz should only be used with a specially made coil e.g. yellow, orange with a 100 ohm resistor or a mat. They are used in the bioresonance and informotherapy. Above 60Hz are supported only the frequencies marked in this document in green color.

Sygnał prostokątny

Vcc= 9-12 [V]

The device is equipped with:

  1. Monostable button;
  2. mini USB port for communication with a PC;
  3. Green LED indicator;
  4. Red LED indicator;
  5. Coil/mat,  charger and biofeedback device socket.

The software and hardware version description:

   4.2 - hardware version – Arduino NANO version 4 series, freePEMF hardware 2 modification
   2016-11-12 - software release date

New versions of the software is available for download from the Github website. The update method is described in the fimware upgrade manual.

Safety of use

Magnetic Therapy Contraindications

Based on the textbook: Fizykoterapia, Wydawnictwo Lekarskie PZWL 2006,  Ph. D Tadeusz Mika & Ph. D Wojciech Kasprzak, ISBN 9788320046632.

  1. Cancer
  2. Pregnancy
  3. Electronic implants. For example, pacemakers, hearing aids and electronically controlled prostheses.
  4. Pulmonary tuberculosis
  5. Bleeding from the gastrointestinal tract
  6. Acute coronary insufficiency
  7. Severe infection of bacterial, viral or fungal origin
  8. Steel implants in animals. Steel implants are not used for people. The pulsating EM field should not be used for postoperative treatment associated with the implantation of steel implants (ferromagnetic materials). The use of magnetotherapy is possible after consultation with a doctor.

In addition, avoid placing the following things less than 1 meter away from the coil or mat:

  1. Electronic devices, including telephones and computers;
  2. Watches, including electronic ones;
  3. Compasses;
  4. Payment cards;
  5. Documents with telemetry data, e.g. passports;
  6. Access cards containing RFID tags, etc;
  7. Devices and objects sensitive to magnetic and electromagnetic fields;
  8. Neodymium magnets;

Please consult your doctor before using this device as a part of your PEMF therapy.

 The freePEMF is not a medical device. Remember that you use the freePEMF device only at your own risk. The author is not responsible for the material and legal consequences of using the freePEMF device on its users, animals, lost revenues and financial losses.

The author designed the device based on his experience as an interesting research project. The freePEMF device has not proper clinical trials on humans or animals, so it is not possible to scientifically confirm its efficiency.

Please note that 15 Hz and 20 Hz frequencies cause anxiety and stress in animals. They should not be used. They are part of the therapy No. 1.

Turning device on

Before beginning therapy, connect the coil or mat to the terminal socket (5). It is not necessary to screw the plug by cap, however, make sure that the plug is fully seated in the socket by pressing it.

Turn the device on by pressing and holding button (1 ) for at least 2 seconds until you hear a short sound signal. The button should be released.

After releasing the button, the green LED should be on. User has 5 seconds to select the therapy number. Select the therapy by pressing the button shortly. The type of therapy selected is indicated by numbers of the sound signals.

Therapy number

Sound signals number

Name and application




Standard regenerative therapy or therapy created by the user.

 Standard therapy consists of :

  • pulsating electromagnetic field naturally occurring on Earth,
  • 15Hz, 20Hz – stimulation capillary formation,
  • 10 Hz - ligaments and joins healing,
  • 7Hz – bone growth,
  • 2Hz nerve regeneration.


Creating your own therapies is described in the bioZAP section or you can download them from Therapies section.

14 min.




Apply in the morning. It consists of two minute cycles of naturally occurring frequencies on our planet: Schumann 7.83Hz resonance.

8 min.



Anti-stress and meditative therapy.

Apply in the evening.

Alpha frequency set (including Earth frequency), Theta (including Schumann) and Delta.

16 min.



Anti-stress therapy and meditative with autopilot.

Apply in the evening.

It uses a heart rate monitor to control therapy as a biofeedback device. Based on the pulse**, the user's state of mind is measured and the transition to the next stages of therapy controlled. Therapy consists of the Alpha, Theta and Delta frequencies.



16 min.


1 h

(*)  The device automatically recognizes the connected heart rate monitor and switches from therapy 3a to 3b.
(**) Pre-calibration is required for the user's pulse parameters. The freePEMF device remembers settings for one user only.


Instrukcja obrazkowa

After the therapy is started its change is not possible. The start of the therapy is signaled by the blinking of the green indicator to the rhythm of the operating frequency delivered to the coil / mat.

Therapies have been designed to change the direction of the electromagnetic field generated by the coil / mat every two minutes.

Turning device off

After turning the device on, it can be turned off by holding down the button for at least 1.5 seconds. When button is released the device turns off. Switching off the device is not possible whilst charging.

Stopping therapy

During work it is possible to stop the therapy temporarily. Press the button 1 briefly. This will be signaled by a short buzzer signal and a steady green light. Pressing the button again will start the rest of the therapy.

The maximum pause time is 10 minutes. After exceeding it, the device will turn itself off automatically.

End of therapy

The device will turn itself off automatically after the therapy is finished. This will be indicated by the green light going off and a short buzzer signal.

If the device stays connected to the PC after finishing work, the green LED will light and the device will remain in control mode via PC. It is possible to shut down the device completely by: holding the button for 1.5 seconds or by issuing the command off from the serial port console. If there is no communication with the PC after about 10 minutes, the device will automatically turn off. Please note that the Arduino module will continue to be powered until the PC was turned off or the USB cable is disconnected.

Emergency stop device

If during the therapy the battery level drops to the minimum level, the device turns itself off by signaling it with a red light and a buzzer signaling several times. In this case, recharge the battery.

Battery charging

The device is equipped with a lead-acid gel battery with a voltage of 12V 1,3Ah. In the event of a complete discharge of the battery, the charging time with a typical charger for gel batteries is 1.5 to 2 hours.

Before connecting to the charger, firstly disconnect all devices, such as a coil or mat (socket 5), a heart rate monitor (socket 5), a PC (socket 2). After connecting the charger to socket 5, the red indicator will light up. The device has its own battery charge control. It measures the voltage on its terminals every several minutes. The charged state of the battery is indicated by the green light on. The red one will continue to light, because the charger supplies power to the battery. It is acceptable to leave the device connected to the correct charger after charging the battery and it will not damage it. 

Connection to PC

PC can control the device directly or to be used to create and load your own therapy script, which will be saved in non-volatile memory. For this purpose, the freePEMF should be connected to the computer's USB port using a standard USB miniUSB-cable. The device automatically detects the connected PC and switches to the PC mode. In this configuration, the computer software has access to read data from the heart rate monitor, the battery charge status, direction relay controller and the coil controller. Through commands of bioZAP script interpreter can create their own therapies, publish them and download them from the website. More information can be found in the bioZAP section.

Biofeedback device - a heart rate monitor

Not working yet.

Choosing the coil

Magnetic induction generated by the device is regulated by the use of a coil or a set of coils in the form of a mat. Coils can be connected in serial or parallel way, keeping in mind that the minimum total resistance can not be less than 6 ohms.

Each flat coil can be described by the following parameters:

  • resistance - can be measured with a multimeter,
  • cross-section of copper wire used for winding - measure with calipers,
  • diameter or radius of the coil - to measure with a ruler,
  • number of coils (turns) - to be counted using a toothpick.

Main coils

Color* Resistance [om] Number of turns Coil radius[cm] Wire diameter [mm] Induction during impulse [uT] Induction RMS [uT] Power RMS [W]
Green 50 44 12 0,12 55,3 27,7 1,45
Red 12 79 10 0,3 493 246 6
Yellow (special) 6 13 8 0,15 193 96 12
Orange  9,4 102/204 10 / 5 0,4 877 / 3500 438/1750 7,6
Blue 8,6 240 5 0,45 4400 2200 8,4

For more information, see the coil and mat instructions.

Commonly used medical devices provide induction at 45mT or 450Gs. It should be added that they operate in a much larger spectrum of frequencies. Frequencies up to 30 Hz have the highest properties penetrating the body. They are also the least absorbed by tissues.

Creating your own therapy scripts

Instead of the first therapy, the user can create his own script in bioZAP language. You can use the following diagram depending on the effect that is desired.

PEMF effect


Therapy protocol

Before starting therapy, remove all metal elements from the body. A magnetic induction coil up to 100 [uT] can be applied to any body part. It should be hold as close as possible. For coils with a higher level of magnetic induction, it should not be applied directly to the head. In the case of the upper body, the coil should be applied to the neck at a height such that the upper part of the coil is not above the line connecting the ear. This placement of the coil is recommended for the third therapy. In the case of using the mat, it is necessary to ensure that head and legs are positioned according to the relevant coils.

Therapy to alleviate the effects of stress and insomnia

Accelerate joint regeneration and healing of injury

Daily morning prevention



Terapia 1



Green coil

Therapy no 3

Orange coil

Therapy no 1


TTherapy no 2