PMOD TC1 Sensor demonstration

This demonstration shows how to use the PmodTC1. You will also see how to plot a graph using matplotlib.

The PmodTC1 is required.

The thermocouple sensor is initialized and set to log a reading every 1 second. The temperature of the sensor can be changed by touching it with warm fingers or by blowing on it.

1. Use TC1 read() to read the current temperature



In [1]:

    
from pynq import Overlay
Overlay("base.bit").download()



In [2]:

    
from pynq.iop import Pmod_TC1
from pynq.iop import PMODB

# TC1 sensor is on PMODB
my_tc1 = Pmod_TC1(PMODB)
r = my_tc1.read()
print('Raw Register Value: %08x hex' % r)
print('Ref Junction Temp:  %.4f' % my_tc1.reg_to_ref(r))
print('Thermocouple Temp:  %.2f' % my_tc1.reg_to_tc(r))
print('Alarm flags:        %08x hex' % my_tc1.reg_to_alarms(r))









    



Raw Register Value: 014416b0 hex
Ref Junction Temp:  22.6875
Thermocouple Temp:  20.25
Alarm flags:        00000000 hex

2. Starting logging temperature once every second



In [3]:

    
my_tc1.start_log()

3. Modifying the temperture

Touch the thermocouple with warm fingers; or
Blow on the thermocouple with cool air

Stop the logging whenever you are finished trying to change the sensor's value.



In [4]:

    
my_tc1.stop_log()
log = my_tc1.get_log()

4. Plot values over time



In [23]:

    
%matplotlib inline

import matplotlib.pyplot as plt
tc = [my_tc1.reg_to_tc(v) for v in log]
ref = [my_tc1.reg_to_ref(v) for v in log]
plt.plot(range(len(tc)), tc, 'ro', label='Thermocouple')
plt.plot(range(len(ref)), ref, 'bo', label='Ref Junction')
plt.title('TC1 Sensor log')
plt.axis([0, len(log), min(tc+ref)*0.9, max(tc+ref)*1.1])
plt.legend()
plt.xlabel('Sample Number')
plt.ylabel('Temperature (C)')
plt.grid()
plt.show()



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