Code upload results in 'USB device has malfunctioned' Windows error - arduino

Question

I am having the same problem as described in this post on the Arduino forums. I have a slight deviation in that I am using an Arduino Leonardo, but otherwise the core problem is the same.
Trying to upload a sketch to my board results in Windows stating my 'USB device has malfunctioned and Windows does not recognize it'. The COM port used for the board then disappears, as with the post above.
I tried the solution posted by Louis Davis in the linked post, which allowed me to successfully reset the board and upload a known good sketch. When this is completed, the board is able to be recognised by Windows again, and the COM port reappears; the board can be used without issue.
I have two Leonardos and I have confirmed by replicating steps across both that it is my specific code which is causing the Windows error to appear, not down to a hardware issue.
Could anyone offer pointers on what in the below code is causing this? (Code is fully commented to describe purpose/methods used)
//Code including basic setup/loop and a function I created, asking for readings to be taken from 3 sensors
//when called, and to then assign the results to global variables
//The loop function should then print the global variables in question and wait for a while before repeating
//the process
#include <Wire.h> //using an I2C breakout (accelerometer)
#include "SparkFun_MMA8452Q.h" //accelerometer breakout's library
MMA8452Q accel; //create an instance of this accelerometer
int FSR_pin = A1; //force resistor pin
const int PHOTO_pin = A0; //phototransistor pin
//declare variables to use to take a base reading, to later measure against for changes
int base_PHOTO = 0;
int base_FSR = 0;
byte base_ORIEN = 0; //using the method recommended in the accelerometer's startup page to get orientation
//readings, which they say is passed back as a byte; section 'Reading Portrait/Landscape'
//on this page https://learn.sparkfun.com/tutorials/mma8452q-accelerometer-breakout-hookup-guide
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
Wire.begin();
}
void baseReading() {
base_FSR = analogRead(FSR_pin);
base_PHOTO = analogRead(PHOTO_pin);
base_ORIEN = accel.readPL();
}
void loop() {
// put your main code here, to run repeatedly:
baseReading(); //call my own function to get base readings
Serial.println(base_FSR);
Serial.println(base_PHOTO);
Serial.println(base_ORIEN);
delay(5000);
}
int takeReading() {
}
I have taken readings from each sensor individually using test sketches from the component manufacturers; the problem only appeared when I tried to combine them into one bit of code. Here's a hyperlink to the accelerometer breakout guide referenced in the above code.

Answer 1

Solved: The code was missing the line accel.init(); from the setup function.
I first ruled out the FSR & phototransistor I was using, as running code for only these components performed as expected. That left the MMA8452Q's code to look at.
I'd been using the manufacturer's guide as linked above for the accelerometer, and Example #3 (orientation reading) from its library to write my code out; I managed to drop the init and assumed the problem was with the new .readPL method I had put in.
The example code uses .begin instead of .init, and also uses this as part of a print statement, so I didn't immediately catch on that the purpose of its inclusion was the same.
The fixed code is as follows:
//Code including basic setup/loop and a function I created, asking for readings to be taken from 3 sensors when called and assigned to global variables
//The loop function should then print the global variables in question and wait for a while before repeating the process
#include <Wire.h>
#include "SparkFun_MMA8452Q.h"
MMA8452Q accel;
int FSR_pin = A1;
const int PHOTO_pin = A0;
//variables to use to take a base reading, to later measure against for changes
int base_PHOTO = 0;
int base_FSR = 0;
byte base_ORIEN = 0;
void setup() {
Serial.begin(9600);
Wire.begin();
accel.init(); //The new line, which allows this to run as intended
}
void baseReading() {
base_FSR = analogRead(FSR_pin);
base_PHOTO = analogRead(PHOTO_pin);
base_ORIEN = accel.readPL();
}
void loop() {
baseReading();
Serial.println(base_FSR);
Serial.println(base_PHOTO);
Serial.println(base_ORIEN);
delay(5000);
}