STC12C5A60S2 flashing

[kazoe]

Hi, Im a beginner in electronics and i found this old mcu that i got from an old led cube from aliexpress. I wanted to reflash it for other purposes, but it does not work... When I click on check MCU, it checks the target MCU, but does nothing. Any advice? Edit: on the power rail is a 10nf and 100pf and at the crystal 2x 47pf.

[WattsThat]

Not familiar with the 12C series but I can suggest two things.

1. RST line needs a 10uf cap in addition to the 10k pull up resistor. Refer to page 383 of the datasheet.
http://www.stcmicro.com/datasheet/STC12C5A60S2-en.pdf

2. Be sure to download an empty program into the Arduino to use the usb<->serial converter as a standalone converter. If the Arduino program has any debug.print statements, there will be activity on the tx pins, confusing the processor.

PS: note the datasheet says <47 pf for the loading caps. 22 pf would probably be a good choice.

[wraper]

47pF capacitance on crystal is a lot. Generally you need about half of that and datasheet shows <47pf, not 47pF.

[coromonadalix]

normally 22pf to 33pf is the go to ??