4.2 inch display can not be flashed

[alexg-k]

You probably don't have all display versions flying around to reproduce and fix this (the error is not even your code, but in the provided NFC.jar from waveshare), but I want to mention it anyway:

Flashing the 4.2 inch version of the display fails for me with "Failed to write over NFC, unknown reason". I modified your code and found out the flashSuccessInt variable shows error code 0 from the returned a()-function.

The following logs appeared during the error:

2022-05-14 16:26:28.005 5150-5150/com.joshuatz.nfceinkwriter I/New intent: New Intent: Intent { act=android.nfc.action.NDEF_DISCOVERED dat=vnd.android.nfc://ext/android.com:pkg flg=0x10000000 cmp=com.joshuatz.nfceinkwriter/.NfcFlasher (has extras) }
2022-05-14 16:26:28.005 5150-5150/com.joshuatz.nfceinkwriter V/Intent.action: android.nfc.action.NDEF_DISCOVERED
2022-05-14 16:26:28.047 5150-5150/com.joshuatz.nfceinkwriter V/Matched!: Tag is a match! Preparing to flash...
2022-05-14 16:26:28.077 5150-5150/com.joshuatz.nfceinkwriter V/NFC Check Loop: START
2022-05-14 16:26:28.695 5150-5501/com.joshuatz.nfceinkwriter W/System.err: java.io.IOException: Transceive failed
2022-05-14 16:26:28.696 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at android.nfc.TransceiveResult.getResponseOrThrow(TransceiveResult.java:52)
2022-05-14 16:26:28.696 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at android.nfc.tech.BasicTagTechnology.transceive(BasicTagTechnology.java:154)
2022-05-14 16:26:28.696 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at android.nfc.tech.NfcA.transceive(NfcA.java:120)
2022-05-14 16:26:28.696 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at waveshare.feng.nfctag.activity.a.a(Unknown Source:48)
2022-05-14 16:26:28.696 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at waveshare.feng.nfctag.activity.a.a(Unknown Source:70)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at waveshare.feng.nfctag.activity.WaveShareHandler.sendBitmap(WaveShareHandler.kt:51)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at com.joshuatz.nfceinkwriter.NfcFlasher$flashBitmap$2.invokeSuspend(NfcFlasher.kt:262)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
2022-05-14 16:26:28.697 5150-5501/com.joshuatz.nfceinkwriter W/System.err:     at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)
2022-05-14 16:26:28.698 5150-5501/com.joshuatz.nfceinkwriter V/Final success val: Success = false
2022-05-14 16:26:28.701 5150-5501/com.joshuatz.nfceinkwriter V/Tag closed: Setting flash in progress = false

Can I provide any more information to find the issue? I will try to contact Waveshare, when I know more about the error.