ssd1306 heltec wireless-stick oled not work correctly

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alien1983
Posts: 9
Joined: Fri Sep 07, 2018 4:52 pm

ssd1306 heltec wireless-stick oled not work correctly

Post by alien1983 » Fri Aug 30, 2019 5:29 pm

Hi,
I'm having trouble displaying pixel text on the screen correctly!


Board: https://heltec.org/project/wireless-stick/

System Image: LoBo MicroPython.

Library:
ssd1306.py

Code: Select all

# MicroPython SSD1306 OLED driver, I2C and SPI interfaces

import time
import framebuf


# register definitions
SET_CONTRAST        = const(0x81)
SET_ENTIRE_ON       = const(0xa4)
SET_NORM_INV        = const(0xa6)
SET_DISP            = const(0xae)
SET_MEM_ADDR        = const(0x20)
SET_COL_ADDR        = const(0x21)
SET_PAGE_ADDR       = const(0x22)
SET_DISP_START_LINE = const(0x40)
SET_SEG_REMAP       = const(0xa0)
SET_MUX_RATIO       = const(0xa8)
SET_COM_OUT_DIR     = const(0xc0)
SET_DISP_OFFSET     = const(0xd3)
SET_COM_PIN_CFG     = const(0xda)
SET_DISP_CLK_DIV    = const(0xd5)
SET_PRECHARGE       = const(0xd9)
SET_VCOM_DESEL      = const(0xdb)
SET_CHARGE_PUMP     = const(0x8d)


class SSD1306:
    def __init__(self, width, height, external_vcc):
        self.width = width
        self.height = height
        self.external_vcc = external_vcc
        self.pages = self.height // 8
        # Note the subclass must initialize self.framebuf to a framebuffer.
        # This is necessary because the underlying data buffer is different
        # between I2C and SPI implementations (I2C needs an extra byte).
        self.poweron()
        self.init_display()

    def init_display(self):
        for cmd in (
            SET_DISP | 0x00, # off
            # address setting
            SET_MEM_ADDR, 0x00, # horizontal
            # resolution and layout
            SET_DISP_START_LINE | 0x00,
            SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0
            SET_MUX_RATIO, self.height - 1,
            SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0
            SET_DISP_OFFSET, 0x00,
            SET_COM_PIN_CFG, 0x02 if self.height == 32 else 0x12,
            # timing and driving scheme
            SET_DISP_CLK_DIV, 0x80,
            SET_PRECHARGE, 0x22 if self.external_vcc else 0xf1,
            SET_VCOM_DESEL, 0x30, # 0.83*Vcc
            # display
            SET_CONTRAST, 0xff, # maximum
            SET_ENTIRE_ON, # output follows RAM contents
            SET_NORM_INV, # not inverted
            # charge pump
            SET_CHARGE_PUMP, 0x10 if self.external_vcc else 0x14,
            SET_DISP | 0x01): # on
            self.write_cmd(cmd)
        self.fill(0)
        self.show()

    def poweroff(self):
        self.write_cmd(SET_DISP | 0x00)

    def contrast(self, contrast):
        self.write_cmd(SET_CONTRAST)
        self.write_cmd(contrast)

    def invert(self, invert):
        self.write_cmd(SET_NORM_INV | (invert & 1))

    def show(self):
        x0 = 0
        x1 = self.width - 1
        if self.width == 64:
            # displays with width of 64 pixels are shifted by 32
            x0 += 32
            x1 += 32
        self.write_cmd(SET_COL_ADDR)
        self.write_cmd(x0)
        self.write_cmd(x1)
        self.write_cmd(SET_PAGE_ADDR)
        self.write_cmd(0)
        self.write_cmd(self.pages - 1)
        self.write_framebuf()

    def fill(self, col):
        self.framebuf.fill(col)

    def pixel(self, x, y, col):
        self.framebuf.pixel(x, y, col)

    def scroll(self, dx, dy):
        self.framebuf.scroll(dx, dy)

    def text(self, string, x, y, col=1):
        self.framebuf.text(string, x, y, col)


class SSD1306_I2C(SSD1306):
    def __init__(self, width, height, i2c, addr=0x3c, external_vcc=False):
        self.i2c = i2c
        self.addr = addr
        self.temp = bytearray(2)
        # Add an extra byte to the data buffer to hold an I2C data/command byte
        # to use hardware-compatible I2C transactions.  A memoryview of the
        # buffer is used to mask this byte from the framebuffer operations
        # (without a major memory hit as memoryview doesn't copy to a separate
        # buffer).
        self.buffer = bytearray(((height // 8) * width) + 1)
        self.buffer[0] = 0x40  # Set first byte of data buffer to Co=0, D/C=1
        self.framebuf = framebuf.FrameBuffer1(memoryview(self.buffer)[1:], width, height)
        super().__init__(width, height, external_vcc)

    def write_cmd(self, cmd):
        self.temp[0] = 0x80 # Co=1, D/C#=0
        self.temp[1] = cmd
        self.i2c.writeto(self.addr, self.temp)

    def write_framebuf(self):
        # Blast out the frame buffer using a single I2C transaction to support
        # hardware I2C interfaces.
        self.i2c.writeto(self.addr, self.buffer)

    def poweron(self):
        pass


class SSD1306_SPI(SSD1306):
    def __init__(self, width, height, spi, dc, res, cs, external_vcc=False):
        self.rate = 10 * 1024 * 1024
        dc.init(dc.OUT, value=0)
        res.init(res.OUT, value=0)
        cs.init(cs.OUT, value=1)
        self.spi = spi
        self.dc = dc
        self.res = res
        self.cs = cs
        self.buffer = bytearray((height // 8) * width)
        self.framebuf = framebuf.FrameBuffer1(self.buffer, width, height)
        super().__init__(width, height, external_vcc)

    def write_cmd(self, cmd):
        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
        self.cs.high()
        self.dc.low()
        self.cs.low()
        self.spi.write(bytearray([cmd]))
        self.cs.high()

    def write_framebuf(self):
        self.spi.init(baudrate=self.rate, polarity=0, phase=0)
        self.cs.high()
        self.dc.high()
        self.cs.low()
        self.spi.write(self.buffer)
        self.cs.high()

    def poweron(self):
        self.res.high()
        time.sleep_ms(1)
        self.res.low()
        time.sleep_ms(10)
        self.res.high()




ssd1306_i2c_example.py

Code: Select all

import machine
from ssd1306 import SSD1306_I2C

#PG MOD
testPin = machine.Pin(16, machine.Pin.OUT)
testPin.value(1) #VEXT ON

WIDTH = const(128)
HEIGHT = const (64)
sda_pin = machine.Pin(4)
scl_pin = machine.Pin(15)

i2c = machine.I2C(scl=scl_pin, sda=sda_pin, speed=400000)

ssd = SSD1306_I2C(WIDTH, HEIGHT, i2c)

import freesans20

from writer import Writer
wri2 = Writer(ssd, freesans20, verbose=True)

Writer.set_clip(True, True)
Writer.set_textpos(0, 0)
wri2.printstring('MicroPython\nby LoBo\n10/2017')

ssd.show()
ssd.pixel(1,1,1)
ssd.pixel(2,2,1)
ssd.pixel(3,3,1)
ssd.pixel(4,4,1)
ssd.pixel(5,5,1)
ssd.pixel(6,6,1)
ssd.pixel(7,7,1)
ssd.pixel(8,8,1)
ssd.pixel(9,9,1)
ssd.pixel(10,10,1)
ssd.pixel(11,11,1)
ssd.pixel(12,12,1)
ssd.pixel(30,30,1)
ssd.show()
Most pixels do not display!
Text do not display correctly,
most are out of the screen.

New settings with :

Code: Select all

WIDTH = const(64)
HEIGHT = const (32)
Setting to the real display value (64x32) also does not work correctly! :/

kindmartin
Posts: 1
Joined: Sun Apr 26, 2020 7:30 am

Re: ssd1306 heltec wireless-stick oled not work correctly

Post by kindmartin » Sun Apr 26, 2020 7:36 am

I have same heltec wireless stick and i cant make this 64x32 oled work!

Any hint?

using this ssd1306 lib >> https://github.com/lemariva/uPySensors/ ... ssd1306.py


from machine import Pin, I2C, SPI, Timer
import ssd1306

oledrst = Pin(16, Pin.OUT)
oledrst.value(0)
oledrst.value(1)

scl_pin = Pin(15, Pin.OUT, Pin.PULL_UP)
sda_pin = Pin(4, Pin.OUT, Pin.PULL_UP)
i2c = I2C(scl=scl_pin, sda=sda_pin, freq=400000)
i2c.scan()

oled = ssd1306.SSD1306_I2C(64, 32, i2c, 0x3c)
oled.fill(0)
t = 'OLED TEST'
oled.text(t,0,0)
oled.show()

User avatar
Roberthh
Posts: 2054
Joined: Sat May 09, 2015 4:13 pm
Location: Rhineland, Europe

Re: ssd1306 heltec wireless-stick oled not work correctly

Post by Roberthh » Sun Apr 26, 2020 8:34 am

You should try the official MP driver here: https://github.com/micropython/micropyt ... ssd1306.py
It was recently updated to deal for instance with that 64x32 display.

b.t.w.: I have uploaded a firmware package for the heltec wireles stick here: https://github.com/robert-hh/Shared-Stuff
It is based on the MicroPython variant of Pycom and contains their LoRaWan support. The easiest way to install that is to use the Pycom installer at https://github.com/pycom/pycom-micropyt ... fw_updater.
That is a wrapper to esptool.py. User the -r option for the espressif reset mode, e.g.:
./updater.py -r -p /dev/ttyUSB0 -s 460800 flash -t HELTEC-1.20.2.rc6.tar.gz
This is just for private use. Since the heltec device has no PSRAM, the heap is rather small. If you have large amounts of data, the Pycom devices are a better choice.

elschopi
Posts: 9
Joined: Tue May 12, 2020 5:12 am
Location: Bavaria, Germany

Re: ssd1306 heltec wireless-stick oled not work correctly

Post by elschopi » Tue May 12, 2020 5:35 am

@Roberthh: first of all, thank you for your work =)
but unfortunately, I do have a small problem using the updater. I'm only beginning my journey with micropython (or python as it is :D) so maybe I've made a stupid mistake.
First, I could not run the updater because my python version was wrong - expected version 2, I had only python 3.x installed - easy fix. But now it gives an import error with serial.tools.list_ports ('No module named serial.tools.list_ports'). Are there any dependencies I need to install first before being able to use it? The esptool.py works fine on my PC (Win 10 32bit).
I'm also using a Heltec Wireless Stick.

Best regards, and thanks in advance

Chris

User avatar
Roberthh
Posts: 2054
Joined: Sat May 09, 2015 4:13 pm
Location: Rhineland, Europe

Re: ssd1306 heltec wireless-stick oled not work correctly

Post by Roberthh » Tue May 12, 2020 5:49 am

You might have to install pyserial for Python2. try
pip2 install pyserial

elschopi
Posts: 9
Joined: Tue May 12, 2020 5:12 am
Location: Bavaria, Germany

Re: ssd1306 heltec wireless-stick oled not work correctly

Post by elschopi » Tue May 12, 2020 6:00 am

Oh. I'll try that, thank you. Unfortunately I can't try it now, as my company PC is not able to use pip (for python 3.x I installed everything needed for esptool by hand :lol: )

edit: I've installed the pyserial module by hand, and now the updater seems to work. It gave me a 'flash operation successful" at least :D

So, thank you again! Have a nice day =)

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