Devices
Output shift registers
Wiring

Wiring

The following components are required for an output shift register or LED driver:

  • The output shift register or LED driver chip.
  • LEDs.
  • Assorted resistors.
  • 0.1µF capacitors.

Pay close attention to the orientation of the LEDs: the anode (long leg) should be connected to the chip and the cathode (short leg) should be connected to GND. This is the opposite of how LEDs are connected to LED driver chips. The 200Ω resistors are required on every output pin with an LED attached.

Schematic for wiring a single 74HC595 chip.

Tip

Using a DM13A or other similar LED driver chip is a better choice than using the 74HC595 for driving LEDs.

Pay close attention to the orientation of the LEDs: the anode (long leg) should be connected to +5V and the cathode (short leg) should be connected to the chip. This is the opposite of how LEDs are connected to a 74HC595.

Schematic for wiring a single DM13A chip.

The value of $R_{\text{ext}}$ determines the amount of current for the LEDs. A 5kΩ resistor results in approximately 12mA per LED, a good brightness level for most situations.

Tip

Connecting pin 21, EN , to a PWM pin on a board enables brightness control of the LEDs as a group from MobiFlight.

Pay close attention to the orientation of the LEDs: the anode (long leg) should be connected to +5V and the cathode (short leg) should be connected to the chip. This is the opposite of how LEDs are connected to a 74HC165.

Schematic for wiring a single TLC5917 chip.

The value of $R_{\text{ext}}$ determines the amount of current for the LEDs. A 1.6kΩ resistor results in approximately 12mA per LED, a good brightness level for most situations.

Tip

Connecting pin 13, OE (ED2), to a PWM pin on a board enables brightness control of the LEDs as a group from MobiFlight.

Output shift registersAdding the device