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lincomatic / open_evse

Firmware for Open EVSE
GNU General Public License v3.0
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PCF8574 support #97

Closed martiinezz closed 5 years ago

martiinezz commented 5 years ago

Hi,

I've been trying to compile firmware with PCF8574 support without luck. I have monochrome based LCD. So far I did get some garbage on the screen while display works great with this library: http://www.mathertel.de/Arduino/LiquidCrystal_PCF8574.aspx

What I did in the code: (openevse.ino) // if using I2CLCD_PCF8574 uncomment below line and comment out LiquidTWI2.h above

include "./LiquidCrystal_I2C.h"

I don't see LiquidTWI2.h anymore. Just doing this didn't help - display acted like dead. So next I did (openevse.h)

// Support PCF8574* based I2C backpack using F. Malpartida's library // https://bitbucket.org/fmalpartida/new-liquidcrystal/downloads

define I2CLCD_PCF8574

No luck as well.

I get garbage (and it's dynamic I can see data changes on the display) only when I do:

define I2LCD

but on the other hand there is

ifndef I2CLCD

undef I2CLCD_PCF8574

endif

I have tried several combinations without luck.

I have also tried to replace LiquidCrystal_I2C.h with LiquidCrystal_PCF8574.h but it seems wire and twi libraries are tied with LiquidCrystal_I2C and it's beyond my skills to fix that :(

lincomatic commented 5 years ago

Hi, make sure you are using the development branch. please try the following, in open_evse.h:

  1. keep I2CLCD enabled
  2. enable I2CLCD_PCF8574
  3. disable RGBLCD
  4. look for the following lines in open_evse.h and make sure LCD_I2C_ADDR is set to the correct I2C address for your LCD
martiinezz commented 5 years ago

Ok, my bad. In the meantime I've build Barbouri THT version and it works fine with your hints. Turned out that by mistake I soldered 24 MHz crystal onto SMD version hence the garbage on the screen. Now what I get is vent error and I don't know how to wire button as PCF expander 8 pins are all used up by LCD.

lincomatic commented 5 years ago

Glad you go it working. You don't have to use I2C for the button. Just look open_evse.h I checked in yesterday. There are instructions for using a SPST-NO button on any available ATmega328P I/O pin. Just set BTN_REG/BTN_IDX properly and connect the switch between the I/O pin and GND.

vegasbrad commented 3 years ago

martiinezz, did you figure out the button pin input, I run a PCF8574 based LCD on some of my builds, and use one of the 6-pin ISP header pins for the button input.