MONK MAKES Mosfetti 4 Channel MOSFET Driver Board Instructions

: October 30, 2023
: MONK MAKES

Table of Contents

MONK MAKES Mosfetti 4 Channel MOSFET Driver Board
Product Information
Product Usage Instructions
Downloading the Examples
ASSEMBLY
USING THE MOSFETTI
DOWNLOADING THE EXAMPLES
RASPBERRY PI PICO
ARDUINO
RASPBERRY PI
TROUBLESHOOTING
SUPPORT
MONKMAKES
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

MONK MAKES Mosfetti 4 Channel MOSFET Driver Board

Product Information

Mosfetti 4-way MOSFET switch

The Mosfetti is a 4-way MOSFET switch designed for low-voltage DC projects such as cars, motorhomes, and model railways. It is compatible with Arduino, Raspberry Pi Pico, Raspberry Pi 4, Beagleboard, and any 3V or 5V microcontroller. The board has one input screw terminal for the supply voltage and four output screw terminals for connecting motors, LED strips, or pumps. Each of the four channels is controlled by the corresponding pin on the 5-way pin header. The fifth pin on the header is the ground or GND pin that must be connected to the microcontroller or single-board computer controlling the Mosfetti.

Product Usage Instructions

Assembly

The Mosfetti comes as a kit with all the surface mount components already soldered on. You need to solder on the header pins and screw terminals. Some projects may be better with leads soldered directly to the pads. Solder the header pins first, as they are the shortest. Put the pin headers in place and then flip the board over onto its back and solder the pins. Sometimes a piece of adhesive putty is useful to keep the pins in position until the first pin is soldered. Next, solder the screw terminals into place, being careful to ensure that the part of the screw terminal into which the wire goes is towards the outside of the board.

Using the Mosfetti

Connect 12V DC to the Mosfetti’s input screw terminal and connect the ground pin (GND) on the Mosfetti’s 5-way pin header to the microcontroller’s GND pin. Connect the four control pins (A to D) on the Mosfetti’s 5-way pin header to the microcontroller’s GPIO pins. The Mosfetti can control up to four motors, LED strips, or pumps. Each channel is controlled by the corresponding pin on the 5-way pin header.

Downloading the Examples

To download the ZIP archive containing example programs for all platforms, visit https://github.com/monkmakes/mosfetti. Click on the Code button, select Download ZIP, and then extract the downloaded ZIP archive. If you are familiar with git and would prefer to download the examples using the command line, then you can do so with the command: $ git clone https://github.com/monkmakes/mosfetti.git With the extracted archive, you will find folders called:

Raspberry Pi Pico

Connect 12V DC to Mosfetti’s input screw terminal and power the Raspberry Pi Pico from USB. Use female-to-male jumper leads to connect the Pico’s GND connection to the Mosfetti’s GND. Connect four of the Pico’s GPIO pins (18, 19, 20, and 21) to the Mosfetti’s control pins A to D. Open the 01_sequence.py program in Thonny (https://thonny.org/) and run it on your Pico. You should see the LED lamps light up in turn and then when all are lit, turn off in sequence.

Example Software

In the pico folder of the Examples folder that you downloaded, you will find two programs: 01_sequence.py and 02_fade.py. Each of the four lamps is associated with a different control pin. A list (lamps) is created that contains all four lamps, making it easy to iterate over each one in turn.

4-way MOSFET switch. Perfect for cars, motorhomes, model railways and other low voltage DC projects. Compatible with Arduino, Raspberry Pi Pico, Raspberry Pi 4, Beagleboard and any 3V or 5V microcontroller.

WARNING

This product is for switching low voltage DC only. Under no circumstances should it be connected to AC.

ASSEMBLY

The Mosfetti comes as a kit, with all the surface mount components already soldered on. You just need to solder on the header pins and screw terminals. Some projects may be better with leads soldered directly to the pads.
Solder the header pins first, as they are the shortest. Put the pin headers in place then flip the board over onto its back and solder the pins. Sometimes a piece of adhesive putty is useful to keep the pins in position until the first pin is soldered.
Next solder the screw terminals into place, being careful to ensure that the part of the screw terminal into which the wire goes is towards the outside of the board.

USING THE MOSFETTI

You can think of the Mosfetti as a 4-channel switch controllable from your favourite microcontroller or single-board-computer. You can switch DC loads such as motors and LED lighting modules (low-voltage DC only) that use far too much current to be connected to a GPIO pin directly. The Mosfetti is compatible with any 3 or 5V microcontroller, such as an Arduino or a Raspberry Pi Pico. You can also connect a Mosfetti to a single-board-computer with GPIO pins such as a Raspberry Pi 4. Here’s an example of how you might wire up a 12V DC power supply and four 12V LED lamps and then control it all from a microcontroller. This example has been made with a Raspberry Pi Pico, and Arduino Uno and a Raspberry Pi 4.

The board has one input screw terminal for the supply voltage, and four outputs, to which motors, or LED strips or pumps can be attached. Each of the four channels labelled A to D and is controlled by the corresponding pin on the 5 way pin header. On the 5 pin header, the fifth pin is the ground or GND pin which must be connected to the microcontroller or single-board-computer controlling the Mosfetti.

DOWNLOADING THE EXAMPLES

To download the ZIP archive containing example programs for all platforms, visit https://github.com/monkmakes/mosfetti

Click on the Code button, select Download ZIP and then extract the downloaded ZIP archive. If you are familiar with git and would prefer to download the examples using the command line, then you can do so with the command:

$ git clone https://github.com/monkmakes/mosfetti.git

With the extracted archive, you will find folders called:

pico – MicroPython examples for the Raspberry Pi Pico
arduino – Arduino, ESP32 and other boards that can be programmed with the Arduino IDE
pi – Raspberry Pi Python examples

RASPBERRY PI PICO

You will need

To build this example project you will need the following items:

A MonkMakes Mosfetti Board
A Raspberry Pi Pico
Solderless Breadboard. The MonkMakes Breadboard for Pico has the Pico pinout printed on it, making pin identification a lot easier (https://monkmakes.com/pico_bb.html).
5 x female to male jumper wires
4 x LED lamp modules (12V). We used 6W COB lighting strips intended for use in cars.
12V power supply

Wiring – Raspberry Pi Pico

12V DC should be connected to the Mosfetti and the Pico powered from USB. The female to male jumper leads are used to connect the Pico’s GND connection to the Mosfetti’s GND and four of the Picos GPIO pins (18, 19, 20 and 21) are connected to the Mosfetti control pins A to D.

Example Software

In the pico folder of the Examples folder that you downloaded you will find two programs: 01_sequence.py and 02_fade.py.

Turning Lamps on and off

Open 01_sequence.py in Thonny (https://thonny.org/) and run it on your Pico.
You should see the LED lamps light up in turn and then when all are lit, turn off in sequence.

Here is the code for 01_sequence.py

Each of the four lamps is associated with a different control pin. A list (lamps) is created that contains all four lamps, making it easy to iterate over each one in turn.

PWM

As well as turning things on and off, the Mosfetti is also capable of Pulse Width Modulation (PWM) to control the brightness of a lamp, or the speed of a motor. The example in 02_fade.py illustrates this.

This time, each control pin is a PWM pin and the brightness is set using the lamp_duty_u16 method. This expects a brightness value of between 0 and 65535. The example program increases the brightness in steps of 256. Try running the example, and you should see how the first lamp gradually works its way up to full brightness and then the next light and so on.

ARDUINO

You will need

To build this example project you will need the following items:

A MonkMakes Mosfetti Board
An Arduino Uno, or other Arduino board. If you use another Arduino -compatible board like an ESP32-based board, then you will need to change the pins that you use. Pick pins that are PWM capable.
5 x female to male jumper wires.
4 x LED lamp modules (12V). We used COB lighting strips intended for use in cars.
12V power supply

Wiring – Arduino Uno

Connect the Arduino and Mosfetti grounds, and four control pins using female to male jumper wires. Use Arduino Uno pins 3, 5, 6 and 10, as these are PWM capable.

Example Software

In the arduino folder of the Examples folder that you downloaded you will find two programs: 01_sequence.ino and 02_fade.ino.

Turning Lamps on and off

Open 01_sequence.ino in the Arduino IDE and upload it to the Arduino.
You should see the LED lamps light up in turn and then when all are lit, turn off in sequence.

Here is the code for this

PWM

As well as turning things on and off, the Mosfetti is also capable of Pulse Width Modulation (PWM) to control the brightness of a lamp, or the speed of a motor. The example in 02_fade.ino illustrates this.
For each lamp in turn analogWrite is used to ramp the brightness up from 0 (off) to 255 (fully on).

RASPBERRY PI

You will need

To build this example project you will need the following items:

A MonkMakes Mosfetti Board
A Raspberry Pi 4. Older versions of Raspberry Pi will also work. The Raspberry Pi should have the latest version of Raspberry Pi OS installed.
5 x female to female jumper wires.
A Raspberry Leaf GPIO template (http://www.monkmakes.com/leaf.html) will make it easier to work out which pin is which.
If you have a Raspberry Pi 400, then a GPIO adapter will make it easier to connect the Mosfetti. (http://www.monkmakes.com/pi_400_gpio.html).
4 x LED lamp modules (12V). We used 6W COB lighting strips intended for use in cars.
12V power supply

Wiring

Use female to female jumper wires to connect the ground and control lines of the Raspberry Pi to the Mosfetti. I used GPIO pins 18, 23, 24 and 25 of the Raspberry Pi.

Example Software

In the pi folder of the Examples folder that you downloaded (see Page 6) you will find two programs: 01_sequence.py and 02_fade.py.

Turning Lamps on and off

On your Raspberry Pi, open a terminal session and if you haven’t already done so, download the example code and change to the pi folder using the commands below:

$ git clone https://github.com/monkmakes/mosfetti.git
$ cd mosfetti/pi

You can then run the first example program like this:

$ python 01_sequence.py

Here’s the code

The code uses the gpiozero module to c3ontrol the GPIO pins. Each lamp is assigned its own pin and a list defined to contain all four lamps.

PWM

As well as turning things on and off, the Mosfetti is also capable of Pulse Width Modulation (PWM) to control the brightness of a lamp, or the speed of a motor. The example in 02_fade.py illustrates this.
In this code, the gpiozero class PWMLED is used, as we want to control the brightness of the lamps.
To set the brightness of a lamp, its value property is set to a number between 0.0 and 1.0.

TROUBLESHOOTING

Problem: The orange power LED in the MonkMakes logo on the Mosfetti does not light.
Solution: Make sure that the power terminal block is properly connected to a DC voltage between 3 and 16V with the correct polarity.
Problem: The orange power LED in the MonkMakes logo on the Mosfetti is lit, but none of the green output LED’s light when a control pin is taken high.
Solution: Make sure that there is not a short circuit, or a load greater than 2A on one of the outputs. Also, make sure that the GPIO pin you are using is set to be an output in your code and is properly connected to the GPIO pin. Che
Problem: I accidentally short-circuited one of the outputs. Have I killed my Mosfetti.
Solution: Not necessarily, the Mosfetti includes a self-resetting fuse, that will often (but not always) protect the Mosfetti against overloading. Disconnect the load and let the Mosfetti cool down for a half a minute and then try the board again. If the green indicator LEDs light, then it shows that the output is switching OK.

SUPPORT

You can find the Product’s information page here: https://monkmakes.com/mosfetti including a datasheet for the product.
If you need further support, please email [email protected].

MONKMAKES

As well as this kit, MonkMakes makes all sorts of kits and gadgets to help with your electronics projects. Find out more, as well as where to buy here: https://monkmakes.com you can also follow MonkMakes on Twitter @monkmakes.