First of all,..very nice project,..nice work !!
Is the PCF8574 chip supported, or will it be supported in the future ?
And can I use it with a max of 8 chips on the same I2C bus ?
support for PCF8574 ?
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Re: support for PCF8574 ?
Hi,
they use the 8574 for the lcd display on port 0x27.
Best is u use the MCP23017, double ports and the possibility of 8 pieces.
And, ... it´s running.
Don´t forget the pull-up resistor in the reset line.
BerndJ
they use the 8574 for the lcd display on port 0x27.
Best is u use the MCP23017, double ports and the possibility of 8 pieces.
And, ... it´s running.
Don´t forget the pull-up resistor in the reset line.
BerndJ
Re: support for PCF8574 ?
As of R41 it is supported. Only available on development branch on github.ILoveIOT wrote:Is the PCF8574 chip supported, or will it be supported in the future ?
Yes you can. Ports in the webgui are numbered 1-8 for the first chip, 9-16 for the second, etc.ILoveIOT wrote:And can I use it with a max of 8 chips on the same I2C bus ?
I guess you know how to work with this device. For newbees, we do advice using the MCP23017 because its a lot easier to use. The PCF8574 has sort of open drain outputs, can only source about 100 uA, so active high output is limited. Ouputs are active high after power on, so active high relay boards go immediately to the active state during boot.
And remember that the ESP is not as stable as one would like... So controlling outputs can lead to undesirable effects during unexpected ESP reboots. Just of word of warning... Used as inputs should be OK.
Re: support for PCF8574 ?
Thank you for the anwsers, I've allot of the PCF8574, so that's why my question, but as you explained,
I will order the MCP23017 chip, and wait a bit Thanks !!
I will order the MCP23017 chip, and wait a bit Thanks !!
Re: support for PCF8574 ?
I got a PCF8574 board here from China.
I jumpered it so that it shows up on address 0x3f (PCF8574, MCP23017, LCD Modules) when scanning the I2C bus.
So far so good.
However, when is set up a task called "Switch input - PCF8574" i don't get any valid status of the corresponding input.
Am i right, that when i set PORT to 1, then i should get the status of the first input?
I tried ports 1..8 but no reaction to signals on any input-pin.
Does anybody know what i am doing wrong?
(I am running build 77)
thanks
chunter
I jumpered it so that it shows up on address 0x3f (PCF8574, MCP23017, LCD Modules) when scanning the I2C bus.
So far so good.
However, when is set up a task called "Switch input - PCF8574" i don't get any valid status of the corresponding input.
Am i right, that when i set PORT to 1, then i should get the status of the first input?
I tried ports 1..8 but no reaction to signals on any input-pin.
Does anybody know what i am doing wrong?
(I am running build 77)
thanks
chunter
Re: support for PCF8574 ?
Port numbering depends on the jumper settings. I've updated the Wiki with a table to get the right portnumbers.
http://www.esp8266.nu/index.php/PCF8574#Input
But at the same time, if discovered a bug within the plugin for the PCF8574A and that one does not currently work!
(if your device is recognized at 0x3F, you must have a PCF8574A type)
Will be fixed in R78 (although I can't really test it because I only have the PCF8574 type)
http://www.esp8266.nu/index.php/PCF8574#Input
But at the same time, if discovered a bug within the plugin for the PCF8574A and that one does not currently work!
(if your device is recognized at 0x3F, you must have a PCF8574A type)
Will be fixed in R78 (although I can't really test it because I only have the PCF8574 type)
Re: support for PCF8574 ?
Thank you very much for the fast update!
Works like a charm in both directions
Works like a charm in both directions
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