Title: EE 647 Digital Signal Processor DSP Based Control of Electric Machines and Drives Laboratory
1EE 647 Digital Signal Processor (DSP) Based
Control of Electric Machines and Drives
Laboratory
- Laboratory Experiment 2
- Lecture Part
Course Supervisor Prof. Ali Keyhani Lab
Instructor Sachin Puranik
2Digital Interfacing- Relays and Switches
- Objective Utilize GPIO ports of 2407 EVM to turn
on or off AC light bulbs using relays - Read digital data from DIP switches
3Circuit Configuration
- Optocoupler Interface Circuit Board
-
- A Hex Inverter Buffers (7406)
- Six Optocouplers (4N35)
- Purpose Used to separate the power supplies of
the microcontroller and the relays
4Optocoupler Interface Circuit Board
- To avoid the large load current fluctuation in
the relay circuit that may get linked to the
logic power supply
5Relays and Lamps Box
- Relay Rating 12 Vdc, 30 mA, SPDT (with contact
rating 10A, 125Vac) - Lamp Rating 25 watts, 115Vac
6Pin Multiplexing and GPIO Overview
- Need of Multiplexing
- - GPIO pins are limited in
- Two functions are multiplexed onto most pins
- Each pin Primary or Secondary Function
7Pin Multiplexing and GPIO Overview
- GPIO pins are grouped in sets of eight pins
called ports (A-F) - What controls pins Primary / Secondary
functionality? - Ans MCRX - MUX Control Register (16-bit register)
8Pin Multiplexing and GPIO Overview
- Write 1 to corresponding bits for primary
function - Write 0 for secondary function
9Pin Multiplexing and GPIO Overview
- When in GPIO mode, what controls the direction ?
(Input or Output) - Ans PxDATDIR Port Data and Direction Control
register (16-bit register)
10Pin Multiplexing and GPIO Overview
- MSBs Control the direction (input or output)
- LSBs Pin data
- (1-output, 0-input)
11DIP Switch Board and EVM Connection
12Relay Interface Circuit and EVM Connection