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olikraus / u8g2

U8glib library for monochrome displays, version 2
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update display timeout > ignore update display? #753

Closed StefanMeGit closed 5 years ago

StefanMeGit commented 5 years ago

Is there any change to check that the display is working while updating it?

I want to handle the case if the SSD1306 breaks or disconnect while running u8g2.clearBuffer(); 8g2.sendBuffer(); or u8g2.firstPage(); u8g2.nextPage()

My program simply stops when I disconnect the display which is not good...

olikraus commented 5 years ago

What kind of communication do you use? I2C? Which Arduino Board?

I assume, the problem will not happen with SPI. It should also not happen with SW-I2C. Actually the problem is not a problem of U8g2 but a problem of the Arduino Wire library on AVR systems (Arduino Uno). The problem might be solved by using proper pullup resistors. Well all in all I can not say much without having more information from your side.

StefanMeGit commented 5 years ago

Oh sorry... I run it on an Samd21 (Adafruit Feather M0) on HW I2C (4 wire connection).

U8G2_SSD1306_128X64_NONAME_F_HW_I2C

PullUp resistor to what?

olikraus commented 5 years ago

Just to clarify: I2C, right? (not SPI, because 4-wire connection usually referes to SPI)

Pull-up resistors for I2C refer to 2K to 10K resistors which connect the clock and data line towards power supply (3.3V in your case). See here: https://www.i-programmer.info/programming/hardware/9124-exploring-edison-i2c-bus.html

StefanMeGit commented 5 years ago

Ok, but I use 4 wires for I2C: VCC GROUND SDA SCL Didn't u need more wires for SPI? VCC GROUND MOSI
CLK DC
CS
RESET

Ok, this pull-ups I am missing. The should be close to the SDA SCL pins on the Ardunios u guess...

EDIT: of course 2 Wire Connection and i2c. I count the vcc and ground as well.

Ok thanks, so the pull-up restores should solve this problem?

olikraus commented 5 years ago

Ok thanks, so the pull-up restores should solve this problem?

It is more like an idea. I know that the hardware I2C subsystem of the AVR (ATMega uC) will halt the uC if there is no I2C device and no pullups. Not sure about the MKR uC.