After protecting the boot loader, did you experience any more bricking issues?
After protection, it has never bricked on my 10 XIAO_SAMD21.
If this is the solution, you would think Seeed would have started shipping them like that, or made a thread on this forum about it. Has there been any comments from Seeed on this issue ?
XIAO_SAMD21 brick issue has been discussed in several threads on this forum, but I donāt think Seeed has ever commented on this issue. FYI, Adafruitās SAMD21 bootloader is factory protected.
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Have sent this over PM
HI there,
So just in generalities , that speed is fast @500K
The SPI rule of
" Syntax
SPI.beginTransaction(SPISettings(14000000, MSBFIRST, SPI_MODE0)) Note: Best if all 3 settings are constants
SPISettings mySetting(speedMaximum, dataOrder, dataMode) Note: Best when any setting is a variableāā
and
If you donāt need to modify the strings or data while your sketch is running, you can store them in flash (program) memory instead of SRAM; to do this, use the PROGMEM keyword.
I recall a LIB you can place in the code that will tell you how much ram is available.
Are you certain it is a BRICK situation and not any other revivable bad reset or halt, temperature ?
always after 4 months, You try a stripped down version with no OLED or graphics, (fonts and drawing)
text only.?
WiFi and MQTT both ?
not on samd21 lots of globals ā¦WOW!
Iāll keep looking.
GL 
PJ 
btw, get same warning to, compiler output.
open C:\Users\Dude\AppData\Local\Arduino15\packages\Seeeduino\hardware\samd\1.8.5\bootloaders\XIAOM0\bootloader-XIAO_m0-v3.7.0-33-g90ff611-dirty.hex: The system cannot find the file specified.
Using library SPI at version 1.0 in folder: C:\Users\Dude\AppData\Local\Arduino15\packages\Seeeduino\hardware\samd\1.8.5\libraries\SPI
Using library Adafruit Zero DMA Library at version 1.0.4 in folder: C:\Users\Dude\AppData\Local\Arduino15\packages\Seeeduino\hardware\samd\1.8.5\libraries\Adafruit_ZeroDMA
Using library Ticker at version 4.4.0 in folder: D:\Arduino_projects\libraries\Ticker
Using library Adafruit GFX Library at version 1.11.10 in folder: D:\Arduino_projects\libraries\Adafruit_GFX_Library
Using library Adafruit BusIO at version 1.16.1 in folder: D:\Arduino_projects\libraries\Adafruit_BusIO
Using library Wire at version 1.0 in folder: C:\Users\Dude\AppData\Local\Arduino15\packages\Seeeduino\hardware\samd\1.8.5\libraries\Wire
Using library Adafruit ST7735 and ST7789 Library at version 1.10.4 in folder: D:\Arduino_projects\libraries\Adafruit_ST7735_and_ST7789_Library
"C:\\Users\\Dude\\AppData\\Local\\Arduino15\\packages\\Seeeduino\\tools\\arm-none-eabi-gcc\\7-2017q4/bin/arm-none-eabi-size" -A "C:\\Users\\Dude\\AppData\\Local\\Temp\\arduino\\sketches\\802399EAD05A4A9BB575E17E783C10E1/UKUS_Toyota_TPMS_Monitor_V12_X.ino.elf"
Sketch uses 63836 bytes (24%) of program storage space. Maximum is 262144 bytes.
I think itās a brick as the Xiao will not respond to reset.
No Wifi or MQTT. The Xiao is communicating with a TI CC1101 though.
Interesting you get the same warningā¦ Was this with a Xiao on the COM port out of interest?
I was previously running that speed at 5MHz
I have not tried a stripped down version but I could. One thing to note is that I implemented this change in the Adafruit lib: Comparing adafruit:master...wmarkow:1.10.7-text-size Ā· adafruit/Adafruit-GFX-Library Ā· GitHub
Hi PJ, any luck?
Sam
Hi there,
No a friend is moving so today was get the truck and load it day, Tonight Iāll give it another look.
Nothing glaring but something is overwriting or a counter is going haywire. (out of bounds)
HTH
GL PJ
No worries. I have a Xiao here that was bricked, is there any way I can read the data off of it and find the cause somehow?
Hi there,
Funny all this time I have never tried that, but I would try with a jlink or programmer just to see what itās status truly is.
HTH
GL PJ
