MkI

00314S2D-ASCII 14 Segment 2 Digit LED Display Module MkI

00314S2D-ASCII is a Daisychain-able 14 Segment, 2 Digit Display Module, designed around the CH32V003 MCU.
It receives 115200 Baud UART Data, in standard ASCII Format, then displays up to 2 Chars per Module. Any Additional chars will be transmitted down the chain of displays.

How to Use

Connect a standard UART TX line, running at 115200 Baud to the RX connection of the module, it is now ready to accept data.
Any ASCII characters will be printed to the display, when one displays buffer is full, it will echo the data on to the next display.
Transmit \n or \r to clear the displays, this will propegate and clear all displays at once.

To Daisychain the displays, connect TX from one, to RX of the next, along with VCC and GND - this will allow you to connect [theoretically] infinite displays in one chain, the only limit being current on VCC.

Building a Module

BOM

RN1        330R 4*0603 Resistor Array
RN2        330R 4*0603 Resistor Array
RN3        330R 4*0603 Resistor Array
RN4        330R 4*0603 Resistor Array
R1         10R 0603
R2         2K2 0603
Q1         AO3400 N-Ch MOSFET SOT-23
Q2         AO3400 N-Ch MOSFET SOT-23
Q3         AO3400 N-Ch MOSFET SOT-23
C1         100nF 0603 MLCC
C2         1uF 0603 MLCC
U1         CH32V003FxPx TSSOP-20
DISP1      Red/Green/Blue 14 Segment 2 Digit Common Cathode Display

Programming

Programming is done via the SWIO TestPoint on the back of the PCB. Once programmed, SWIO is disabled to be used as a normal GPIO. To Reprogram the deivce, connect a programmer to the SWIO pin, and power cycle the device - this will put the device into program mode.

1. Connect SWIO Pin
2. Apply Power to the Module
3. Run minichlink -D to allow NRST to be a GPIO Pin
4. Flash the binary to the IC

NOTE: make will do both of these steps automatically if the user chooses to use that toolchain

[TODO] Make MkII PCB with better programming ports
Make MkII PCB have MCU and resistors on rear side for easier repair (?)
Build automatic testing jig to validate modules before displays are attached
Investigate segment failure issue

MIT License Copyright (c) 2024 ADBeta