Weird bevaviour with STC15W408AS

[Kobbe1]

Hi there,

I have what I believe is one of the banggood kits. I did successfully flash this firmware a while ago, I can't quite remember what settings though. Recently I fried the µ-controller while trying to flash - I think by connecting it incorrectly.

I therefore replaced the micro - however not with the STC15F204EA as originally but with an STC15W408AS I thought to be pin compatible.

I played with the compile options - but I only get the result as attached. The right most digit goes on/off with light level.

I swapped the segment port and digit and interestingly the pattern changes completely, telling me that the micro is indeed driving the segments somehow.

Any ideas? Maybe pullups one of the µ-controllers has and the other does not?

Thanks a lot,

-Kobbe

[zerog2k]

This looks different from the ones this firmware is for. This firmware is for variants which drive individual 7 segment digits. Yours looks like maybe it has a 4x 7-segment display driven as a single unit, which probably has slightly different pinout.

The STC15F204EA and STC15W404AS/408AS are essentially same pinout, just the others have more ram, code, and peripherals

Do you have a schematic?

[zerog2k]

If you are sure it was working before with this firmware, perhaps it's one of the variants, e.g. HW_MODEL_C review this issue: https://github.com/zerog2k/stc_diyclock/issues/20 and if it is, likely you could try building it with this option added to platformio.ini: build_flags = -DHW_MODEL_C

[Kobbe1]

Sorry for the delay but wanted to try it again to be sure. I had played around with the DHW_MODEL_C flag in the makefile before, tried it again, but 0 change. The only thing that makes a difference is to swap digit and segment port in the code - still not readable but the readout changes. Just in case below is a log of the last build in case you spot any dumb mistakes ...

`~/stc_diyclock$ make sdcc -o build/ src/main.c --code-size 4089 --xram-size 0 --data-loc 0x30 --disable-warning 126 --disable-warning 59 -Dstc15f204ea -DWITH_ALT_LED9 -DWITHOUT_LEDTABLE_RELOC -DSHOW_TEMP_DATE_WEEKDAY -DHW_MODEL_C build/adc.rel build/ds1302.rel Name Start End Size Max

---

ROM/EPROM/FLASH 0x0000 0x0dff 3584 4089
cp build/main.ihx main.hex

~/stc_diyclock$ STCGALPROT="stc15" make flash stcgal/stcgal.py -p /dev/ttyUSB0 -P stc15 -t 11059 main.hex Waiting for MCU, please cycle power: done Target model: Name: STC15W408AS Magic: F51F Code flash: 8.0 KB EEPROM flash: 5.0 KB Target frequency: 11.075 MHz Target BSL version: 7.2.5T Target wakeup frequency: 36.600 KHz Target options: reset_pin_enabled=False clock_source=internal clock_gain=high watchdog_por_enabled=False watchdog_stop_idle=True watchdog_prescale=256 low_voltage_reset=True low_voltage_threshold=3 eeprom_lvd_inhibit=True eeprom_erase_enabled=False bsl_pindetect_enabled=False por_reset_delay=long rstout_por_state=high uart2_passthrough=False uart2_pin_mode=normal cpu_core_voltage=unknown Loading flash: 3584 bytes (Intel HEX) Trimming frequency: 11.057 MHz Switching to 19200 baud: done Erasing flash: done Writing flash: 3648 Bytes [00:03, 1038.72 Bytes/s]
Finishing write: done Setting options: done Target UID: F51F44B103089C Disconnected! `

[zerog2k]

Can you share schematics? It’s the only way I can see what is different.

[Kobbe1]

I have another one coming from banggood, will scan schematic once I have it. Is there a way to backup the original firmware or is this locked?

[zerog2k]

No, no known way to readout flash - the STC uart bootloader rom does not support reading (by design).

[Kobbe1]

Hi there, the new kit arrived. Guess what - it is a different hardware altogether. I will close this issue here, the old clock has a hardware issue I am convinced now.

I will open a new one as also the new kit gives me trouble, this clock drives me crazy :)