HELP!
I want to use a Shunt Matrix Array FSR that I have bought and built using the instructions on this website thats for a Thru Matrix Array Tutorials: FSR MatrixArray
It says it can be adjusted but I can't work it out and I am going round in circles! Can anyone help?
The supplied code is included and the schematic is on the page which I have built my model according to, with the extra rows included on the spare 74HC4051 pins
/**********************************************************************************************************
* Project: MatrixArray.ino
* By: Chris Wittmier @ Sensitronics LLC
* LastRev: 09/09/2015
* Description: FSR MatrixArray Demonstration of Sensitronics' 16x10 element resistive ThruMode. Scanning
* electronics consist of 2 HCT595 shift registers, and 2 4051 multiplexers connected to Arduino Uno.
**********************************************************************************************************/
/**********************************************************************************************************
* MACROS / PIN DEFS
**********************************************************************************************************/
#define BAUD_RATE 115200
#define ROW_COUNT 10
#define COLUMN_COUNT 16
#define PIN_ADC_INPUT A0
#define PIN_SHIFT_REGISTER_DATA 2
#define PIN_SHIFT_REGISTER_CLOCK 3
#define PIN_MUX_CHANNEL_0 4 //channel pins 0, 1, 2, etc must be wired to consecutive Arduino pins
#define PIN_MUX_CHANNEL_1 5
#define PIN_MUX_CHANNEL_2 6
#define PIN_MUX_INHIBIT_0 7 //inhibit = active low enable. All mux IC enables must be wired to consecutive Arduino pins
#define PIN_MUX_INHIBIT_1 8
#define ROWS_PER_MUX 8
#define MUX_COUNT 2
#define CHANNEL_PINS_PER_MUX 3
/**********************************************************************************************************
* GLOBALS
**********************************************************************************************************/
int current_enabled_mux = MUX_COUNT - 1; //init to number of last mux so enabled mux increments to first mux on first scan.
/**********************************************************************************************************
* setup()
**********************************************************************************************************/
void setup()
{
Serial.begin(BAUD_RATE);
pinMode(PIN_ADC_INPUT, INPUT);
pinMode(PIN_SHIFT_REGISTER_DATA, OUTPUT);
pinMode(PIN_SHIFT_REGISTER_CLOCK, OUTPUT);
pinMode(PIN_MUX_CHANNEL_0, OUTPUT);
pinMode(PIN_MUX_CHANNEL_1, OUTPUT);
pinMode(PIN_MUX_CHANNEL_2, OUTPUT);
pinMode(PIN_MUX_INHIBIT_0, OUTPUT);
pinMode(PIN_MUX_INHIBIT_1, OUTPUT);
}
/**********************************************************************************************************
* loop()
**********************************************************************************************************/
void loop()
{
for(int i = 0; i < ROW_COUNT; i ++)
{
setRow(i);
shiftColumn(true);
shiftColumn(false); //with SR clks tied, latched outputs are one clock behind
for(int j = 0; j < COLUMN_COUNT; j ++)
{
int raw_reading = analogRead(PIN_ADC_INPUT);
byte send_reading = (byte) (lowByte(raw_reading >> 2));
shiftColumn(false);
printFixed(send_reading);
Serial.print(" ");
}
Serial.println();
}
Serial.println();
delay(200);
}
/**********************************************************************************************************
* setRow() - Enable single mux IC and channel to read specified matrix row.
**********************************************************************************************************/
void setRow(int row_number)
{
if((row_number % ROWS_PER_MUX) == 0) //We've reached channel 0 of a mux IC, so disable the previous mux IC, and enable the next mux IC
{
digitalWrite(PIN_MUX_INHIBIT_0 + current_enabled_mux, HIGH); //Muxes are enabled using offset from MUX_INHIBIT_0. This is why mux inhibits MUST be wired to consecutive Arduino pins!
current_enabled_mux ++;
if(current_enabled_mux >= MUX_COUNT)
{
current_enabled_mux = 0;
}
digitalWrite(PIN_MUX_INHIBIT_0 + current_enabled_mux, LOW); //enable the next mux, active low
}
for(int i = 0; i < CHANNEL_PINS_PER_MUX; i ++)
{
if(bitRead(row_number, i))
{
digitalWrite(PIN_MUX_CHANNEL_0 + i, HIGH);
}
else
{
digitalWrite(PIN_MUX_CHANNEL_0 + i, LOW);
}
}
}
/**********************************************************************************************************
* shiftColumn() - Shift out a high bit to drive first column, or increment column by shifting out a low
* bit to roll high bit through cascaded shift register outputs.
**********************************************************************************************************/
void shiftColumn(boolean is_first)
{
if(is_first)
{
digitalWrite(PIN_SHIFT_REGISTER_DATA, HIGH);
}
digitalWrite(PIN_SHIFT_REGISTER_CLOCK, HIGH);
digitalWrite(PIN_SHIFT_REGISTER_CLOCK, LOW);
if(is_first)
{
digitalWrite(PIN_SHIFT_REGISTER_DATA, LOW);
}
}
/**********************************************************************************************************
* printFixed() - print a value padded with leading spaces such that the value always occupies a fixed
* number of characters / space in the output terminal.
**********************************************************************************************************/
void printFixed(byte value)
{
if(value < 10)
{
Serial.print(" ");
}
else if(value < 100)
{
Serial.print(" ");
}
Serial.print(value);
}
