SW8B PCB0042 LSD

Serial Wombat SW8B PCB0042 LSD

Eight Channel I2C Controlled Low Side Driver

PRELOADED FIRMWARE IMAGE:

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LSD Usage Guide (See user manual below for overall Serial Wombat guide):

  • Wombat Pins 0 through 7 enable N-Channel drivers. Digital Output, PWM, or Frequency Output pin modes are typical.

Board is tested up to 4 amps per channel, or 8 amps simultaneous across the board at 24V. Each channel has a flyback diode for switching inductive loads and optional Active LEDs.

Logic voltage is 3.3 to 5V. Transistors are more efficient at 5V.

Header sockets and screw down terminals are available for all load voltage inputs and for channel outputs. Each channel output has a connection for switched low side and for unswitched high side. Marking the low side of the green screw down connectors with a black marker is suggested if the board is to be used for benchtop experimentation in order to reduce the likelyhood of polarity mix-ups.

Header socket connectors are not suitable for full 8A usage. Screw terminals with adequate wire diameter should be used for higher current applications.

Solder Jumper options:

  • I2C address for the Serial Wombat chip can be configured between 0×60 and 0×6F through closing the 4 address solder jumpers located near the corner of the board. 2.54mm headers can optionally be added to allow the address to be set with header pin jumpers.

  • 2200 ohm I2C Bus pull up resistors can be added by closing the pull up solder jumpers at the corner of the board.

  • Channel 1 can be converted from an output to an analog input that measures load voltage by soldering the two jumpers in the WP1 MEAS box. This creates an always-on 1:11 voltage divider that can be measured by configuring the Serial Wombat pin 1 to an analog input. Channel 1 can still optionally be used as an ouput by driving the pin high or low. See schematic for details.

  • A logic voltage indicator LED can be enabled by closing the solder jumper near the 10 pin socket.

  • Channel Active LEDs can be enabled by closing the solder jumper marked “Active LEDs”. This connects a green LED from load Vin to each transistor with a 10k current limiting resistor.

  • A load voltage input indicator LED can be enabled by closing the solder jumper marked “Vin LED”.

Basic Sample Arduino Sketch (see more in the library):

/* This example shows how to use the Serial Wombat PCB0042 LSD to drive outputs 0 and 2 through 7

* And read the voltage feedback on output 1 (assumes the solder jumper is enabled for pin 1)

*

* It cycles through each output setting it to 25, 50, 75, and 100% duty cycle then turning it back off

‍ */

#include <SerialWombat.h>

PCB0042_LSD_PWM swBoard;

#define PCB0042_I2C_ADDRESS 0x60

void setup() {

// put your setup code here, to run once:

Wire.begin(); //Initialize the I2C Bus on default pins

Serial.begin(115200);

delay(3000);

Serial.println("PCB0042 PWM output Example. ");

‍ ‍

swBoard.begin(PCB0042_I2C_ADDRESS, true); // Initialize board and configure pin 1 to be an analog feedback.

‍ ‍

}

uint8_t pin = 0;

void loop() {

Serial.print("Input voltage is ");

Serial.println(swBoard.readVin_mV());

swBoard.outputArray[pin]->writePublicData(0x4000); // 25% duty cycle

delay(500);

swBoard.outputArray[pin]->writePublicData(0x8000); // 50% duty cycle

delay(500);

swBoard.outputArray[pin]->writePublicData(0xC000); // 75% duty cycle

delay(500);

swBoard.outputArray[pin]->writePublicData(0xFFFF); // 100% duty cycle

delay(500);

swBoard.outputArray[pin]->writePublicData(0); // 0% duty cycle

++pin;

if (pin == 1) {++pin;} // Using pin 1 for Vin analog input

if (pin == 8) {pin = 0;}

}

Online PCB Viewer / Model Download

Revision History

PCB0042_V3:

First Public Release

PCB0042_V2:

Internal Version

PCB0042_V1:

Internal Version

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