The maximum clock frequency for the MAX7219CWG-T is 10MHz. However, it's recommended to operate at a clock frequency of 4MHz or less to ensure reliable operation.
To initialize the MAX7219CWG-T, you need to send a shutdown command (0x0C, 0x01) followed by a display-test command (0x0F, 0x01) and then a scan-limit command (0x0B, 0x07) to set the number of digits to be displayed. Finally, send a shutdown command (0x0C, 0x00) to turn on the display.
The No-Op command (0x00, 0x00) is used to synchronize the microcontroller's clock with the MAX7219CWG-T's clock. It's recommended to send a No-Op command after power-up or after a reset to ensure proper synchronization.
The brightness of the display can be adjusted by sending a intensity-command (0x0A, 0x00 to 0x0A, 0x0F) to the MAX7219CWG-T. The intensity value ranges from 0 (minimum brightness) to 15 (maximum brightness).
The maximum current consumption of the MAX7219CWG-T is 330mA, assuming all segments are on and the display is operating at the maximum brightness.
MAX7219CWG-T datasheet
by Maxim Integrated Products
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