lvgl with monocrome display not working

[1Gootch1]

PROBLEM DESCRIPTION

When switching from 15.1.0 to 15.2.0 my monochrome SH1106 display is not working anymore.

Displaying Text via the Console works. But using berry lvgl doesn't.

I used the same configuration option in both version also switching back again to 15.1.0 to make sure hardware is ok. It seems there was a major rework of the uDisplay driver therefore I also compiled my own image (15.2.0) with the uDisplay lib from 15.1.0 and it worked. So the issue seems to be the uDisplay rework between 15.2.0 and 15.1.0

REQUESTED INFORMATION

Make sure your have performed every step and checked the applicable boxes before submitting your issue. Thank you!

• Read the Contributing Guide and Policy and the Code of Conduct
• Searched the problem in issues
• Searched the problem in discussions
• Searched the problem in the docs
• Searched the problem in the chat
  Same problem with ST7735S and 15.02.0
• Problem is not scripter related, in this case open a discussion and tag gemu2015
• Device used (e.g., Sonoff Basic): WS32 ETH01
• Tasmota binary firmware version number used: 15.02.0
  • Pre-compiled
  • Self-compiled
• Flashing tools used: web installer
• Provide the output of command: Backlog Template; Module; GPIO 255:

  Configuration output here:
09:05:13.464 RSL: RESULT = {"NAME":"WT32_ETH01","GPIO":[1,1,1,1,1,1,0,0,1,0,1,1,3840,576,5600,0,0,0,0,5568,0,0,0,0,0,0,0,0,1,1,0,1,1,0,0,1],"FLAG":0,"BASE":1}
09:05:13.671 RSL: RESULT = {"Module":{"0":"WT32_ETH01"}}
09:05:13.876 RSL: RESULT = {"GPIO0":{"Option A3":6210},"GPIO1":{"None":0},"GPIO2":{"None":0},"GPIO3":{"None":0},"GPIO4":{"I2C SDA1":640},"GPIO5":{"None":0},"GPIO6":{"None":0},"GPIO7":{"None":0},"GPIO8":{"None":0},"GPIO9":{"None":0},"GPIO10":{"None":0},"GPIO11":{"None":0},"GPIO12":{"None":0},"GPIO13":{"None":0},"GPIO14":{"I2C SCL1":608},"GPIO15":{"None":0},"GPIO16":{"Output Hi":3840},"GPIO17":{"LedLink_i":576},"GPIO18":{"ETH MDIO":5600},"GPIO19":{"None":0},"GPIO20":{"None":0},"GPIO21":{"None":0},"GPIO22":{"None":0},"GPIO23":{"ETH MDC":5568},"GPIO24":{"None":0},"GPIO25":{"None":0},"GPIO26":{"None":0},"GPIO27":{"None":0},"GPIO32":{"None":0},"GPIO33":{"None":0},"GPIO34":{"None":0},"GPIO35":{"None":0},"GPIO36":{"None":0},"GPIO37":{"None":0},"GPIO38":{"None":0},"GPIO39":{"None":0}}

• If using rules, provide the output of this command: Backlog Rule1; Rule2; Rule3:

  Rules output here:

• Provide the output of this command: Status 0:

  STATUS 0 output here:
09:10:19.335 CMD: Status 0
09:10:19.337 RSL: STATUS = {"Status":{"Module":0,"DeviceName":"Tasmota","FriendlyName":["Tasmota"],"Topic":"tasmota_693328","ButtonTopic":"0","Power":"1","PowerLock":"0","PowerOnState":3,"LedState":1,"LedMask":"FFFF","SaveData":1,"SaveState":1,"SwitchTopic":"0","SwitchMode":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"ButtonRetain":0,"SwitchRetain":0,"SensorRetain":0,"PowerRetain":0,"InfoRetain":0,"StateRetain":0,"StatusRetain":0}}
09:10:19.371 RSL: STATUS1 = {"StatusPRM":{"Baudrate":115200,"SerialConfig":"8N1","GroupTopic":"tasmotas","OtaUrl":"http://ota.tasmota.com/tasmota32/release/tasmota32-lvgl.bin","RestartReason":"Vbat power on reset","Uptime":"0T00:00:07","StartupUTC":"2026-01-21T08:10:12","Sleep":50,"CfgHolder":4617,"BootCount":11,"BCResetTime":"2026-01-20T20:18:51","SaveCount":21}}
09:10:19.403 RSL: STATUS2 = {"StatusFWR":{"Version":"15.2.0(release-lvgl-haspmota)","BuildDateTime":"2025-12-12T10:58:08","Core":"3.3.4","SDK":"5.3.4.251205","CpuFrequency":240,"Hardware":"ESP32-D0WD v1.0","CR":"403/699"}}
09:10:19.426 RSL: STATUS3 = {"StatusLOG":{"SerialLog":2,"WebLog":2,"MqttLog":0,"FileLog":0,"SysLog":0,"LogHost":"","LogPort":514,"SSId":["Porterhouse Steak",""],"TelePeriod":300,"Resolution":"558180C0","SetOption":["00008009","2805C80001000600003C5A0A192800000000","00000080","00006000","00004000","00000000"]}}
09:10:20.576 RSL: STATUS4 = {"StatusMEM":{"ProgramSize":2608,"Free":271,"Heap":108,"StackLowMark":18,"PsrMax":0,"PsrFree":0,"ProgramFlashSize":4096,"FlashSize":4096,"FlashChipId":"16405E","FlashFrequency":80,"FlashMode":"DIO","Features":["0809","8FAAC7DF","00048021","000006CF","010013C0","40000981","40004080","00200000","5400003D","800200A0","00000004"],"Drivers":"1,2,!3,!4,!5,!8,9,10,12,13,!16,!20,!24,26,!27,29,38,50,52,54,55,!56,62,!67,!68,82,!88,!121","Sensors":"1,2,3,5,6,8,9,85,127","I2CDriver":"7,9,10,58,59,77"}}
09:10:20.621 RSL: STATUS5 = {"StatusNET":{"Hostname":"tasmota-693328-4904","IPAddress":"192.168.25.167","Gateway":"192.168.25.1","Subnetmask":"255.255.255.0","DNSServer1":"192.168.25.1","DNSServer2":"0.0.0.0","Mac":"40:F5:20:69:33:28","IP6Global":"","IP6Local":"fe80::42f5:20ff:fe69:3328%st1","Ethernet":{"Hostname":"tasmota-693328-4904-eth","IPAddress":"0.0.0.0","Gateway":"0.0.0.0","Subnetmask":"0.0.0.0","DNSServer1":"192.168.25.1","DNSServer2":"0.0.0.0","Mac":"00:00:00:00:00:00","IP6Global":"","IP6Local":""},"Webserver":2,"HTTP_API":1,"WifiConfig":4,"WifiPower":16.0}}
09:10:20.664 RSL: STATUS6 = {"StatusMQT":{"MqttHost":"","MqttPort":1883,"MqttClientMask":"DVES_%06X","MqttClient":"DVES_693328","MqttUser":"DVES_USER","MqttCount":0,"MqttTLS":0,"MAX_PACKET_SIZE":1200,"KEEPALIVE":30,"SOCKET_TIMEOUT":4}}
09:10:20.686 RSL: STATUS7 = {"StatusTIM":{"UTC":"2026-01-21T08:10:20Z","Local":"2026-01-21T09:10:20","StartDST":"2026-03-29T02:00:00","EndDST":"2026-10-25T03:00:00","Timezone":"+01:00","Sunrise":"08:33","Sunset":"17:29"}}
09:10:20.710 RSL: STATUS10 = {"StatusSNS":{"Time":"2026-01-21T09:10:20"}}
09:10:20.716 RSL: STATUS11 = {"StatusSTS":{"Time":"2026-01-21T09:10:20","Uptime":"0T00:00:08","UptimeSec":8,"Heap":106,"SleepMode":"Dynamic","Sleep":10,"LoadAvg":99,"MqttCount":0,"Berry":{"HeapUsed":5,"Objects":61},"POWER":"ON","Wifi":{"AP":1,"SSId":"Porterhouse Steak","BSSId":"FC:EC:DA:1A:C0:6E","Channel":6,"Mode":"HT40","RSSI":50,"Signal":-75,"LinkCount":1,"Downtime":"0T00:00:03"},"Hostname":"tasmota-693328-4904","IPAddress":"192.168.25.167"}}

• Set weblog to 4 and then, when you experience your issue, provide the output of the Console log:

  Console output here:
00:00:00.001 HDW: ESP32-D0WD v1.0 
00:00:00.028 UFS: FlashFS mounted with 304 kB free
00:00:00.037 CFG: Loaded from File, Count 23
00:00:00.043 QPC: Count 1
00:00:00.043 CFG: CR 403/699, Busy 0
00:00:00.046 I2C: Bus1 using GPIO14(SCL) and GPIO04(SDA)
00:00:00.050 TFS: File 'mcp23x.dat' not found
00:00:00.050 MCP: Invalid template
00:00:00.050 TYA: Active=0
00:00:00.053 ROT: Mode 1
00:00:00.059 BRY: GC from 3794 to 3594 bytes, objects freed 4/22 (in 0 ms) - slots from 38/61 to 30/61
00:00:00.079 CFG: No '*.autoconf' file found
00:00:00.088 BRY: GC from 6870 to 5187 bytes, objects freed 9/48 (in 1 ms) - slots from 73/91 to 50/91
00:00:00.088 BRY: Berry initialized, RAM used 5187 bytes
00:00:00.096 BRY: No 'preinit.be'
00:00:00.115 DSP: File descriptor used
00:00:00.115 I2C: SH1106 found at 0x3c
00:00:00.243 DSP: SH1106 initialized
00:00:00.248 SRC: Restart
00:00:00.252 Project tasmota - Tasmota Version 15.2.0(release-lvgl-haspmota)-3.3.4(2025-12-12T10:58:08)
00:00:00.255 LVG: Allocating buffer1 10 KB in main memory (flushlines 40)
00:00:00.262 LVG: LVGL initialized
00:00:00.646 ETH: Bad EthType 0 or init error
00:00:00.674 BRY: No 'autoexec.be'
00:00:00.936 WIF: Checking connection...
00:00:00.937 WIF: Attempting connection...
00:00:01.255 WIF: Connecting to AP1 Porterhouse Steak Channel 6 BSSId FC:EC:DA:1A:C0:6E in mode HT40 as tasmota-693328-4904...
00:00:02.566 WIF: IPv4 192.168.25.167, mask 255.255.255.0, gateway 192.168.25.1
00:00:03.491 WIF: IPv6 Local fe80::42f5:20ff:fe69:3328%st1
00:00:03.701 WIF: Checking connection...
00:00:03.702 WIF: Connected
00:00:03.960 HTP: Web server active on tasmota-693328-4904 with IP address 192.168.25.167
00:00:03.962 NTP: Sync time...
00:00:03.980 WIF: DNS resolved '2.pool.ntp.org' (78.47.93.191) in 18 ms
00:00:04.034 RTC: UTC 2026-01-21T08:10:58Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00

TO REPRODUCE

Steps to reproduce the behavior:
Use a SH1106 Display and try to display something via berry lvgl

EXPECTED BEHAVIOUR

A clear and concise description of what you expected to happen.
same behavior of the display in 15.2.0 as in 15.1.0

SCREENSHOTS

If applicable, add screenshots to help explain your problem.

ADDITIONAL CONTEXT

Add any other context about the problem here.

(Please, remember to close the issue when the problem has been addressed)

[lz64]

I am having the exact same experience with the display in my WT32-SC01 PLUS display

[Jason2866]

Try latest development, changes done in uDisplay driver.

[1Gootch1]

Nop I just compiled the latest development branch same result as with 15.2.0.
Display Text works but no splash screen and no berry lvgl.
The lvgl screen mirror extension shows the correct display content but the screen is blank.

[lz64]

that is what i am experiencing as well i had claude take a stab at it for about an hour yesterday but nothing done in that hour made any difference to the end the result so i discarded all the changes

…

On Thu, Jan 22, 2026 at 12:59 PM 1Gootch1 ***@***.***> wrote: *1Gootch1* left a comment (arendst/Tasmota#24376) <#24376 (comment)> Nop I just compiled the latest development branch same result as with 15.2.0. Display Text works but no splash screen and no berry lvgl. The lvgl screen mirror extension shows the correct display content but the screen is blank. — Reply to this email directly, view it on GitHub <#24376 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AMFTYI5Q2O3GDEH3EF5VKM34IEFY3AVCNFSM6AAAAACSL4VV2CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTOOBVHA3TQNJYGE> . You are receiving this because you commented.Message ID: ***@***.***>

[sfromis]

Did a small test with ESP32 + SSD1306, using DisplayText first (countdown with timestamp), and then a simple HASPmota text. As HASPmota sits on top of LVGL, this should test both. To make it self-contained, I'm creating test.jsonl in the oneliner Berry code in the last rule of the set.

Rule1
on System#init do Backlog Power1 on; var1 5; RuleTimer1 1 endon
on Rules#Timer==1 do Sub1 1 endon
on var1#state>=0 do Backlog RuleTimer1 1; DisplayText [zx0y0s1]%timestamp%[x0y16s2]%var1% endon
on var1#state<0 do Br var fh=open('test.jsonl','w') fh.write('{"page":1,"id":1,"obj":"label","x":0,"y":0,"w":128,"align":0,"text":"Hello World","bg_color":"#000000","text_color":"#FFFFFF"}') fh.close() import haspmota haspmota.start(false,'test.jsonl') endon

For me, DisplayText works on all versions, but on 15.1.0 the HASPmota example gets a white background without text. On 15.2.0 no signs of initialization as display stayed on last DisplayText output. Only got both tests to work by going back to version 14.5.0, and the textless white background behavior starting with version 14.6.0

No improvement upgrading from release 15.2.0 to latest dev 15.2.0.4. Testing done with tasmota32-lvgl.bin

[arendst]

Although latest fix might not solve the OPs issue, it does solve rotation issues on SPI displays.

[sfromis]

Indeed no difference for my SSD1306 test case with latest dev.
"Version":"15.2.0.4(f2ea225-lvgl-haspmota)","BuildDateTime":"2026-01-26T14:01:49"

[sfromis]

@gemu2015 While your fix from today made a difference to my test case above, to no longer just leave the DisplayText results visible when starting HASPmota, now returning to the behavior seen from 14.6 to 15.1, where the HASPmota step merely produces a white (or whatever color the monochrome pixels have) background, I'm still having the issue of not getting the text rendered. Of course, this regression did not happen with 15.2, as I found out that I only see it working as expected by going back to version 14.5.

Using latest precompiled tasmota32-lvgl.bin from today:
"Version":"15.2.0.4(7f7a2ce-lvgl-haspmota)","BuildDateTime":"2026-01-27T10:28:45"

[gemu2015]

we now use the original (identical) push colors monochrome routine as with 14.5.

i tested with several jpeg pictures and not with haspmota but i can't figure out a difference in code from 14.5

try to change this (in 14.5 it is called from LVGL with "true")

void uDisplay::pushColors(uint16_t *data, uint32_t len, boolean not_swapped) {

if (lvgl_param.swap_color) {
    not_swapped = !not_swapped;
}
if (!universal_panel->pushColors(data, len, not_swapped)) {
    //pushColorsMono(data, len, not_swapped);
    pushColorsMono(data, len, true);
}

[sfromis]

With that attempt, I saw nothing changed, still no text rendered, only getting the bright background painted.

[gemu2015]

with lvgl enabled i get this screen

note:
// pixel is white if at least one of the 3 components is above 50%

[gemu2015]

btw the exact call must be as follows

if (!universal_panel->pushColors(data, len, not_swapped)) {
    pushColorsMono(data, len, !not_swapped);
}