)
I'm sure we can poke at the code and wiring you have.
OK, still getting nowhere.
I'm now convinced that my wiring is OK. I've checked the datasheet and double-checked the board.
I've just found a blog that says Arduino is incompatible wtih 74HC166, and to use 74HCT166 instead. Is this true? They don't explain why.
http://eq-av.com/?p=AVBR&PHPSESSID=ced18f58fbba1a1403817274dfe310cf
It also seems that most people are using the 165, but I couldn't get those without paying £20 postage!
The code is different for 165 and 166, and I can't get my head round it.
What I'm trying to do is write an Input Function that reads the state of multiple switches attached to the 166, and put the results into a byte.
I then assign the bits from the byte into my variables.
My current code is a mess, hacked from numerous examples, so I need to start over.
The code mentioned in previous post LOOKS like it should work, but not for me.
in Main Loop:
byte incoming = readbits();
function for readbits()
set clock high
set latch low
delay
set latch high //to get rising edge to begin read
for i=0 to 7
set clock low
read input pin
set clock high
add pin state to newbyte
end for
set latch high // to end reading
return newbyte
//Define Variables here
int latchPinInput = 7;
int clockPinInput = 9;
int dataPinInput = 10;
byte incoming;
int state;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(latchPinInput, OUTPUT);
pinMode(clockPinInput, OUTPUT);
pinMode(dataPinInput, INPUT);
}
void loop() {
// put your main code here, to run repeatedly:
incoming = readbits();
Serial.print(incoming);
}
byte readbits(){
byte newbyte = 00000000;
digitalWrite(latchPinInput, LOW); // loads her up to be read
delay(15);
digitalWrite(clockPinInput, HIGH);
digitalWrite(latchPinInput, HIGH); // (on a rising signal)
for (int i=0; i <= 7; i++){ // count through the items (bits) in the array
digitalWrite(clockPinInput, LOW);
state = digitalRead(dataPinInput);
digitalWrite(clockPinInput, HIGH);
Serial.print(" Pin ");
Serial.print(i);
Serial.print(": ");
Serial.print(state);
bitWrite (newbyte, i, state);
Serial.print(" ");
Serial.print(newbyte, BIN);
delay(15);
}
Serial.print(newbyte);
Serial.println(); ///////// ==========
digitalWrite(latchPinInput, HIGH); // close her down and switch to display mode
return newbyte;
}Have you poked around in http://www.nxp.com/documents/data_sheet/74HC_HCT166.pdf ?
I put another 'delay' in there and adjusted comments. It looks fine to me at the moment...
You can technically use almost any value... but it's safe to consider the 'input' pin on an Arduino to be 1MΩ .. and if you use resistor values that are too low, you will be wasting energy heating them up. 10k sounds perfect to meYes, I've got Pin 9 HIGH.
I'm about ready to give up on this thing! I'm blaming my less-than-full understanding of Shift Registers, and the 166 being a lot less documented/discussed than the 165.
I've had some ideas on how to save pins using Analogue inputs:
e.g. for the stop/slow/fast, have a 3-way switch that goes across 2 resistors as a Voltage Divider. Stop = 0V, Slow = between resistors. ~2.5V, Fast = 5V.
e.g. something similar for Hull Points up/down. Hold a line at ~2.5V, press UP to momentarily push it to 5V, DOWN button momentarily connects to GND. Arduino spots these pulses and changes Hull Point value accordingly.
(Opens a new question: What value resistors for voltage divider? 10K? Both the same, to get 0V/2.5V/5V)
As I've saved loads of pins using the Output Shift Register (which works fine), I have more Input pins left, less need for Input Shift Register. Would have been nice to get it running, but this is not a "Get a Shift Register to Work" project.
Pinout looks fine to me.. I'm curious why you are having the problems you are... You said Arduino was putting out 5V...
Oh well.)Good to hear.Thanks for your continued help. It is much appreciated.
I am moving on from Shift Register inputs*, and have wired/coded a proof-of-concept Analogue input.
I have a 3-way switch connected to a voltage divider, giving Analogue values of ~0, ~512, ~1023 (actually pretty solid, stable values!), and an if ... else statement assigning variables accordingly.
I shall see about building this into the larger Project.
(Minor issue is the 3-way switch is not designed for breadboard! Have jammed it in, but it falls out easily!
*I might come back to them later. But for now, I'd rather have something that works!
The output register works just fine.
It's pretty similar to your switch idea... the protection resistor will prevent he analogue input from reaching 0 or 1023 depending on which end the analogue input gets connected to.(Was typing when your reply came in!)
3-way speed-selector wired into analogue input on "real" circuit.
Have had to remove all wiring and code for all other inputs.
NEXT: Analogue Input for HP +/-
I was going to have the input wired to the centre of two 10K resistors (holding it at 2.5V) and two switches. One shorts the input to 5V, the other shorts the input to GND.
This looks fine unless both are pressed together (which should never happen, but if I don't protect it, it WILL happen!), shorting 5V to GND - BOOM!
Can each switch have a resistor (what value?) to protect the circuit? (Picture attached)
Voltage Ladder. I vaguely recall that phrase!
Currently I'm thinking of keeping unrelated switches on separate inputs, but yes, can squeeze more in that way!
) (Again, should only press one at once, BUT ...)Yessir! Just like the picture... but you should ignore the values I quoted earlier... The buttons will still provide unique values to the Arduino.Something like this pic?
Sounds good. Better than my idea of shorting 5V to GND!
I can read/display the values to adjust the code (I'm sure you're values are right, but my circuit may be a little off
This means I can put all 3 guns on one button, too!
Excellent! Ditching the shift-register hasn't been a waste of time, we've made great progress here!
Big Thanks again. I owe you a drink!
Sounds good. I'm in no rush
