Search found 8 matches
- Sat Jan 06, 2018 7:35 pm
- Forum: Interface
- Topic: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
- Replies: 18
- Views: 63388
Re: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
I attached a 4x3 keypad to this Port Expander. Works nice with the standard i2ckeypad.h library I also attached an LCD with I2C Backpack SHield. In this way an I2C keypad is achieved. But.... if I have NO LCD attached, this fails after a couple of keypresses. It seems that the I2C bus is messed up. ...
- Mon Nov 27, 2017 3:54 pm
- Forum: Interface
- Topic: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
- Replies: 18
- Views: 63388
Re: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
Hi Andrew, Many thanks. Now it works as a charm. I and my friends completely overlooked that Mode is a Boolean, not a byte, so the bit manipulation in the previous .cpp were not allowed. A small but important difference. (It would be great if the Arduino compiler would have complained..) My sincere ...
- Sun Nov 26, 2017 2:23 pm
- Forum: Interface
- Topic: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
- Replies: 18
- Views: 63388
Re: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
Would be great if this issue can be solved. I too checked the library and neither do I see any explanation why the order makes any difference. Of course knowing the issue is also the way to get around. But I included this Port Expander in a course for my students. And it is difficult to explain to t...
- Sat Nov 25, 2017 6:23 pm
- Forum: Interface
- Topic: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
- Replies: 18
- Views: 63388
Re: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
I am just blinking two leds as a demonstration of this phenomenon. My code: My code: #include "HCPCF8574.h" //Include the HCPCF8574 library byte I2C_ADD = 0x20; //I2C address of the PCF8574 HCPCF8574 Port(I2C_ADD); //Create an instance of the library int PortLedpinA = 0; int PortLedpinB = 1; void se...
- Sat Nov 25, 2017 11:24 am
- Forum: Interface
- Topic: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
- Replies: 18
- Views: 63388
Re: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
Hi all, I have a problem with the PCF8574 port expander I can not explain. 2 led's are connected by means of 330Ohm resistor to Vcc and to pin0 and pin1. They are supposed to blink simultaneously. The code is of maximum simplicity. When I define the Port.pinMode in increasing order it works. Port.pi...
- Wed Nov 01, 2017 12:12 pm
- Forum: Interface
- Topic: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
- Replies: 18
- Views: 63388
Re: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
Many thanks. I got it!
- Tue Oct 31, 2017 6:12 pm
- Forum: Interface
- Topic: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
- Replies: 18
- Views: 63388
Re: PCF8574 I2C to 8-bit digital port expander (HCMODU0120)
I received 3 of these and tested them, there Hex Address start at 0x20 for the current devices which are PCF8574T. if the chip is PCF8574A the start Address is 0x38 the Sketch will need to be altered accordingly. I.E #define I2C_ADD 0x20 I can't find the library. Could you post a working link pleas...
- Tue Oct 31, 2017 6:08 pm
- Forum: Arduino
- Topic: HCPCF8574 - Library for PCF8574 8 bit port expander
- Replies: 11
- Views: 33005
Re: HCPCF8574 - Library for PCF8574 8 bit port expander
The link to the HCPCF8574 library is broken.
Can anyone provide me with this library?
Thanks in advance!
Paul
Can anyone provide me with this library?
Thanks in advance!
Paul