Download - Special Design Report
Special Design ReportSpecial Design Report
IMDL Summer 2002
Matthew Chernosky
July 11, 2002
OverviewOverview
Additional hardware Pulse Width Modulation channels
Need for additonal PWM channelsDesignResults
Need for additional channelsNeed for additional channels
Atmel ATMega163 – 3 PWM channels built-in
Motion – Requires 2 channels (left and right)
Golf ball pickup– Needs more than one channel
DesignDesign
2 additional channels to be implemented
Channels used for locomotionAltera MAX7032 CPLDDevelopment in VHDL
DesignDesign
3 Settings for each channel– Forward– Reverse– Stopped
A 2-bit wide input bus selects desired setting for each channel
4 output port pins of uP
DesignDesign
AlteraMAX7032
AtmelMega163
1 MHzoscillator
MicrocontrollerCPLD
PWM A Out
PWM B Out
Chan A select
Chan B select
DesignDesign
15-bitcounter
CPLD
PWM A
PWM B
FF
FFLogic
Chan A select
Chan B select
1 MHz clock
Reset
VHDLVHDL
ENTITY motor_pwm_580 IS
PORT(
clk : in STD_LOGIC;
PWM_IN_A: in STD_LOGIC_VECTOR(1 downto 0);
PWM_IN_B: in STD_LOGIC_VECTOR(1 downto 0);
PWM_OUT_A: out STD_LOGIC;
PWM_OUT_B: out STD_LOGIC
);
END motor_pwm_580;
VHDLVHDL
cnt: PROCESS (clk)BEGIN
IF (clk = '1' and clk'EVENT) THENif (count < COUNT_MAX) then
-- increment countercount <= count + 1;
else-- reset counter when COUNT_MAX reachedcount <= COUNT_RST;
end if;END IF;
END PROCESS;
ResultsResults
Oscilliscope waveform tests
Works with servos
20 ms
1.75 ms
