Question one: The display module interface for the three-wire serial interface (B) type, no display after power-on display, connected to the emulator how to debug also did not reflect what is the reason?
Answer: The module of type three-wire serial interface (B) is automatically put into hibernation after power-on, the display has no waveform output and the display shows nothing, which is normal. If no any reflection when debugging, should first check whether the connection is correct, the connection is reliable, and then find the reasons from the following aspects:
If you use 51 series MCU, please download the interface program, and do not modify any part of the interface subroutine; and then simulator step by step debugging, and measured with a multimeter output port line, confirm the line level and the program corresponds. If not 51 series MCU, please refer to 51 series MCU interface program, and in accordance with the interface timing, single-step debugging, while measuring the output port with a multimeter to confirm the line level and program and interface timing corresponding. If you really can not debug out, please contact with my company, if necessary, send back the module for testing.
Question two: SMC1602 and other character display module Why a row of black block?
Answer: Because the default mode 16X1 of the character display module such as SMC1602 is power-on, a row of black blocks will be displayed on power-up. When your main program to initialize it, the display mode is set to 16X2 successfully, the black block will disappear.
Question three: display module for the digital segment module, why the LCD screen is not displayed on the paragraph is also faint now?
Answer: This phenomenon is called "ghosting", this is because the multi-channel driven display module uses a scanning mode, there is voltage not displayed in the pen segment, under normal circumstances, the voltage away from the threshold voltage of liquid crystal, the pen Segment performance is not displayed, but if the module's operating voltage rises beyond the normal operating voltage, the voltage close to the threshold voltage of liquid crystal, the paragraph will be faintly present. To solve this phenomenon mainly from the following two aspects:
1, plus the main circuit regulator circuit, the working voltage remained stable.
2, notify us, in the display module LCD bias will be lowered. Change the design, inform us to add the regulator circuit in the display module, the LCD bias voltage is fixed, not with the external operating voltage changes.