Absolute Encoder RM22SC interfacing with IC DS26LS32CN and Launchpad F28379D
Mukendi Alonso
am 11 Jul. 2024
Hi everyone,
I need deep orientation to make calculation of speed and Angle for the absolute encoder RM22SC with signal (data+, Data-, Clock +, Clock -) using Launchpad F28379D and Simulink.
I did interface the absolute encoder with IC DS26LS32CN and I did get signal Data and Clock. I did use the GPIO20 for Data and GPIO21 for Clock and connect both to the Matlab Function block to get as output the position. See the code on attached. The output of the Matlab function times 2*pi/8192 to get the angle. However, I don't get anything as value.
Matlab Fuction Block code
function position = decodeSSI(data, clock)
%#codegen
persistent bitCounter shiftRegister prevClock
if isempty(bitCounter)
bitCounter = uint32(0);
shiftRegister = uint32(0);
prevClock = uint32(0);
end
% Parameters
numBits = 13; % Number of bits in the SSI word
% Rising edge detection for clock
clock = uint32(clock); % Ensure clock is of type integer
clockRisingEdge = (clock == 1) && (prevClock == 0);
prevClock = clock;
if clockRisingEdge
bitCounter = bitCounter + 1;
% Shift in the data bit
shiftRegister = bitor(bitshift(shiftRegister, 1), uint32(data));
% Check if we have received the full word
if bitCounter == numBits
position = shiftRegister;
% Reset for the next word
bitCounter = uint32(0);
shiftRegister = uint32(0);
else
position = uint32(0); % or NaN to indicate incomplete data
end
else
position = uint32(0); % or retain the last valid position
end
end
