Wipy 2.0 and save data on my pc, not in flash memory
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@robert-hh sorry, can I ask you about another problem?
I extract data from I2C and i do lot of calculation in real time.
I need data in real time and I compare them in real time to some reference value to give feedback to the subject. But my code has a problem.MemoryError: memory allocation failed, allocating 1954 bytes``` How I can solve it? Thank you -
@vflorio94 WiPy2 is short of RAM.
If that happens immediately during import, then you may have to put some of your code into frozen bytecode. For that, you have to build you own firmware images. Once set up, that is not complicated. But the way of setting up looks difficult, even if it's not. Just follow the documentation step by step.If the message comes up when the code runs, adding
gc.collect()at certain places in your code may help to reduce heap fragmentation.Some information can also be found here: http://docs.micropython.org/en/latest/pyboard/reference/speed_python.html, sections "Buffers", "Arrays" and "Controlling garbage collection"
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@robert-hh thank you, I use the command gc.collect() as you suggets but the first time that I run my code it works, but then, when I want to run for the second time the same code, it print me the same error in memory allocation.
In my code I define a function and I call it in another part of my code.
I call the function that calculate the position every 1 second during a time interval of 20 second.so, what do you think that it's better to do ?
thank you a lot -
@vflorio94 So it looks like a heap fragmentation problem, and it's hard to tellm what to do without knowing the code. The basic rule with heap fragmentation is to avoid allocation of large objects over and over, and instead to allocate buffers only once and re-use them. If slices are needed, use memoryview to create a slice.
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@robert-hh
in the code, first I collect the data about position in a time interval of 1 second and I immediately use this data to set an output.
But in the next second I need to recalculate the data position and the data that i use before now aren't important and I don't need them.
I go on like this for 20 second or more. -
@vflorio94 The error message shown below:
MemoryError: memory allocation failed, allocating 1954 bytestells, that your code wants to allocat a chunk of memory. What line is causing that? Doese teh code create a buffer, or doesn it try to write to a file?
Just the explanation of the code does not help, we need the source to help you, since it's about the little details. -
@robert-hh the line isn't indicate.
I show you the code if you can help me i'll be greatfulimport machine import pycom from machine import Timer import time import lib_imu from machine import I2C from math import sqrt from machine import PWM import gc def media(sequenza): # calculate mean return sum(sequenza[1:len(sequenza)]) / (len(sequenza)-1) def varianza(sequenza): # calculate variance mean = media(sequenza) return sum([(x-mean)**2 for x in sequenza])/len(sequenza) def dev_std(sequenza): # Calculate standard deviation return sqrt(varianza(sequenza)) def calcolo_position(secondi): # function to calculate the position each second, the number of second is assigned gc.collect() # Configure I2C to extract euler angle lib_imu.set_configmode() time.sleep(0.03) # set unit lib_imu.set_units() time.sleep(0.03) # set mode lib_imu.set_mode('ndof') # create 3 lists lista_heading = [] lista_roll = [] lista_pitch = [] t = Timer.Chrono() t.start() time.sleep(0.1) while 1: t_now = t.read() if t_now <= secondi: eul = lib_imu.get_euler() lista_heading.extend([eul[0]]) lista_roll.extend([eul[1]]) lista_pitch.extend([eul[2]]) time.sleep(0.5) if ( ((secondi - 0.5) < t_now < secondi) & (len(lista_heading) == len(lista_roll)) & (len(lista_roll) == len(lista_pitch))): # Calculate mean and standard deviation print(lista_heading) print(lista_roll) print(lista_pitch) l = len(lista_pitch) print("Calcolo media") for i in range (0,l): mean_pitch = media(lista_pitch) mean_roll = media(lista_pitch) mean_heading = media(lista_heading) mean_pos = (mean_heading,mean_roll,mean_pitch) # Calcolo deviazione standard dev_std_heading = dev_std(lista_heading) dev_std_roll = dev_std(lista_roll) dev_std_pitch = dev_std(lista_pitch) devstd_pos =(dev_std_heading, dev_std_roll, dev_std_pitch) return mean_pos, devstd_pos else: t.stop() gc.collect() del lista_heading[0:l] del lista_pitch[0:l] del lista_roll[0:l] print("Acquisizione terminata") break def acquisizione_interval_pitch(delta_t,sec, mean_pos_ok,mean_pos_no, dev_std_no ): lib_imu.set_configmode() lib_imu.set_units() lib_imu.set_mode('ndof') pwm = PWM(1, frequency=2000) # timer indica il tempo di oscillazione alla specifica frequenza pwm_c5 = pwm.channel(5, pin='P12') #dietro pwm_c4 = pwm.channel(4, pin='P7') # dx pwm_c3 = pwm.channel(3, pin='P6') pwm_c2 = pwm.channel(2, pin='P5') # avanti pwm_c1 = pwm.channel(1, pin='P3') # sx pwm_c5.duty_cycle(0) time.sleep(0.01) pwm_c4.duty_cycle(0) time.sleep(0.01) pwm_c3.duty_cycle(0) time.sleep(0.01) pwm_c2.duty_cycle(0) time.sleep(0.01) pwm_c1.duty_cycle(0) time.sleep(0.01) # DAC dacRight = machine.DAC('P21') #right dacLeft = machine.DAC('P22') #left dacRight.deinit() dacLeft.deinit() # Intervallo di inclinazione if mean_pos_no[2] < mean_pos_ok[2]: position_intervalPitch = (mean_pos_ok[2] - mean_pos_no[2] - (dev_std_no[2])/2 ) elif mean_pos_no[2] > mean_pos_ok[2]: position_intervalPitch = (mean_pos_no[2] - mean_pos_ok[2] - (dev_std_no[2])/2 ) print("intervallo totale", position_intervalPitch) delta_i = position_intervalPitch / 4 #imposto un valore fisso per la suddivisione dell'intervallo # CRONOMETRO chrono_i = Timer.Chrono() chrono_i.start() time.sleep(0.01) position_sec = [] while 1: chrono_i_now = chrono_i.read() x = 500 y = 3 if chrono_i_now <= delta_t: gc.collect() position_sec = calcolo_position(sec) media_pos_sec= position_sec[0] dev_std_pos_sec = position_sec[1] # Calcolo per il pitch : movimento avanti-indietro # Calcolo posizioni di partenza, tenendo conto della std: # - maggiore di 90° indietro # - minore di 90° avanti start_p_av = (mean_pos_ok[2] - (dev_std_no[2])/2 ) start_p_ind = (mean_pos_ok[2] + (dev_std_no[2])/2 ) print("start avanti",start_p_av ) print("start ind",start_p_ind) # Movimento AVANTI: pwm C2 = P5 if media_pos_sec[2] <= mean_pos_ok[2]: if start_p_av <= media_pos_sec[2] < (start_p_av - delta_i): # for x in seq: # pwm_c2.duty_cycle(x) pwm_c2.duty_cycle(0.3) pwm_c4.duty_cycle(0) pwm_c5.duty_cycle(0) pwm_c1.duty_cycle(0) time.sleep(0.01) dacLeft.deinit() dacRight.init() dacRight.tone(x,y) time.sleep(0.01) elif (start_p_av - delta_i) <= media_pos_sec[2] < (start_p_av - (2)*delta_i): pwm_c2.duty_cycle(0.5) pwm_c5.duty_cycle(0) pwm_c4.duty_cycle(0) pwm_c1.duty_cycle(0) time.sleep(0.05) dacLeft.deinit() dacRight.init() x= x + 1000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) elif (start_p_av - 2*delta_i) <= media_pos_sec[2] < (start_p_av - (3)*delta_i): pwm_c5.duty_cycle(0) pwm_c4.duty_cycle(0) pwm_c2.duty_cycle(0.7) pwm_c1.duty_cycle(0) time.sleep(0.01) dacLeft.deinit() dacRight.init() x= x + 2000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) elif (start_p_av - 3*delta_i) <= media_pos_sec[2] < (start_p_av - (4)*delta_i): pwm_c5.duty_cycle(0) pwm_c4.duty_cycle(0) pwm_c2.duty_cycle(0.8) pwm_c1.duty_cycle(0) time.sleep(0.01) dacLeft.deinit() dacRight.init() x= x + 3000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) elif media_pos_sec[2] <= (start_p_av - 4*delta_i) : pwm_c5.duty_cycle(0.5) pwm_c4.duty_cycle(0.5) pwm_c2.duty_cycle(0.5) pwm_c1.duty_cycle(0.5) time.sleep(0.01) dacLeft.deinit() dacRight.init() x= x + 4000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) # Movimento INDIETRO: pwm C5 = P12 elif media_pos_sec[2] > mean_pos_ok[2]: if start_p_ind <= media_pos_sec[2] < (start_p_ind + delta_i): # for x in seq: # pwm_c2.duty_cycle(x) pwm_c2.duty_cycle(0) pwm_c4.duty_cycle(0) pwm_c5.duty_cycle(0.3) pwm_c1.duty_cycle(0) time.sleep(0.01) dacLeft.deinit() dacRight.init() dacRight.tone(x,y) time.sleep(0.01) elif (start_p_ind + delta_i) <= media_pos_sec[2] < (start_p_ind + (2)*delta_i): pwm_c2.duty_cycle(0) pwm_c5.duty_cycle(0.5) pwm_c4.duty_cycle(0) pwm_c1.duty_cycle(0) time.sleep(0.05) dacLeft.deinit() dacRight.init() x= x + 1000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) elif (start_p_ind + 2*delta_i) <= media_pos_sec[2] < (start_p_ind + (3)*delta_i): pwm_c5.duty_cycle(0.7) pwm_c4.duty_cycle(0) pwm_c2.duty_cycle(0) pwm_c1.duty_cycle(0) time.sleep(0.01) dacLeft.deinit() dacRight.init() x= x + 2000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) elif (start_p_ind + 3*delta_i) <= media_pos_sec[2] < (start_p_ind + (4)*delta_i): pwm_c5.duty_cycle(0.8) pwm_c4.duty_cycle(0) pwm_c2.duty_cycle(0) pwm_c1.duty_cycle(0) time.sleep(0.01) dacLeft.deinit() dacRight.init() x= x + 3000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) elif media_pos_sec[2] >= (start_p_ind + 4*delta_i) : pwm_c5.duty_cycle(0.5) pwm_c4.duty_cycle(0.5) pwm_c2.duty_cycle(0.5) pwm_c1.duty_cycle(0.5) time.sleep(0.01) dacLeft.deinit() dacRight.init() x= x + 4000 y = y - 1 dacRight.tone(x,y) time.sleep(0.01) time.sleep(0.01) dacRight.deinit() dacLeft.init() x= x + 1000 y = y - 1 dacLeft.tone(x,y) time.sleep(0.01) else: chrono_i.stop() print("fine prova") pwm_c5.duty_cycle(0) pwm_c4.duty_cycle(0) pwm_c2.duty_cycle(0) pwm_c1.duty_cycle(0) dacRight.deinit() dacLeft.deinit() break # the instruction like the main, in which I use the function print("START ACQUISITION") print("Rilevazione posizione corretta") time.sleep(1) position_ok = [] position_ok = calcolo_position(6) mean_pos_ok = position_ok[0] print("media posizione corretta", mean_pos_ok[2]) dev_std_ok = position_ok[1] gc.collect() print("END FIRST ACQUISITION") time.sleep(2) print("SECOND AQUISITION ") time.sleep(1) position_no =[] position_no = calcolo_position(6) mean_pos_no = position_no[0] dev_std_no = position_no[1] gc.collect() print("END SECOND AQUISITION") time.sleep(1) print("START test pitch") time.sleep(1) acquisizione_interval_pitch(20, 1, mean_pos_ok, mean_pos_no, dev_std_no ) -
@vflorio94 Which line is causing the error?
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@robert-hh I think that the error can be caused by the function "Calcolo_position', because I call it more and more time when the code run
thank you -
@vflorio94 When the error pops ups, there is usually a line number shown. Which line number is it?
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@robert-hh there isn't any line number.
only this message╝MemoryError: memory allocation failed, allocating 2029 bytes ╝> MicroPython v1.8.6-849-56d00234 on 2018-05-18; WiPy with ESP32 Type "help()" for more information.``` -
@vflorio94 A few questions:
So you call calcolo_position() and it never returns, but gives that error?
The intention of calcolo_position(sec) is to collect data for the time sec, about 2 values per second, and return the average values?
Is the exact time the acquisition runs important?
Edit:
what is returned by lib_imu.get_euler()? -
@robert-hh
The intention of calcolo_position(sec) is which you have write. The function collect 2 values each second, calculate mean and re-use this value in the next function "acquisizione_interval_pitch", to generate the output.
I need to mantain this time of acquisition because i work on subject and I want to extract data about their trunk posture in real time. I want to give them some feedback in real time.lib_imu is a simple library create to extract by I2c BNO055.
lib_imu.get_euler return the Euler Angle of pitch, roll and yaw. -
@vflorio94 said in Wipy 2.0 and save data on my pc, not in flash memory:
lib_imu.get_euler return the Euler Angle of pitch, roll and yaw.
I am asking about the data type: Does it return a tuple with three float values?
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@robert-hh Sorry, I didn't understand your question before.
it returns TUPLE
thank you for your help and your patience -
@vflorio94 In the first step, i changed two functions, media and calcolo_position. I simplified calcolo_position and reordered some lines. The major problem as I guess was a termination problem. It simply never hit the 0.5 second window for termination. It still is not perfect in matters of memory allocation, because it would better preallocate the "lists" as arrays. But that is a bigger change.
I changed media(), because the way it is it would implicitely allocate a list. The way it is now it's a little bit slower.def calcolo_position(secondi): # function to calculate the position each second, the number of second is assigned gc.collect() # Configure I2C to extract euler angle lib_imu.set_configmode() time.sleep(0.03) # set unit lib_imu.set_units() time.sleep(0.03) # set mode lib_imu.set_mode('ndof') # create 3 lists lista_heading = [] lista_roll = [] lista_pitch = [] t = Timer.Chrono() t.start() time.sleep(0.1) while 1: t_now = t.read() if t_now <= secondi: eul = lib_imu.get_euler() lista_heading.append(eul[0]) lista_roll.append(eul[1]) lista_pitch.append(eul[2]) time.sleep(0.5) if t_now > (secondi - 0.5): # Calculate mean and standard deviation print(lista_heading) print(lista_roll) print(lista_pitch) print("Calcolo media") mean_pos = (media(lista_pitch), media(lista_pitch), media(lista_heading)) # Calcolo deviazione standard devstd_pos = (dev_std(lista_heading), dev_std(lista_roll), dev_std(lista_pitch)) return mean_pos, devstd_pos else: t.stop() del lista_heading del lista_pitch del lista_roll gc.collect() print("Acquisizione terminata") breakdef media(sequenza): # calculate mean mean = 0.0 for _ in range (1, len(sequenza)): mean += sequenza[_] return mean / (len(sequenza)-1) -
@robert-hh thank you for your help, but also after the changes that you suggest the error stay.
i think that I need to preallocate the list as arrays, but I don't know i can do. i've never programming with python before.
Could you help me please? -
@vflorio94 I simplified calcoco_position() slightly more and added a print statement. can you tell me how far that progresses, and what is the argument you call calcoso:position(9 with?
def calcolo_position(secondi): # function to calculate the position each second, the number of second is assigned gc.collect() # Configure I2C to extract euler angle lib_imu.set_configmode() time.sleep(0.03) # set unit lib_imu.set_units() time.sleep(0.03) # set mode lib_imu.set_mode('ndof') # create 3 lists lista_heading = [] lista_roll = [] lista_pitch = [] t = Timer.Chrono() t.start() time.sleep(0.1) while 1: t_now = t.read() if t_now <= secondi: print("t-now = ", t_now) eul = lib_imu.get_euler() lista_heading.append(eul[0]) lista_roll.append(eul[1]) lista_pitch.append(eul[2]) time.sleep(0.5) else: t.stop() print(lista_heading) print(lista_roll) print(lista_pitch) print("Calcolo media") mean_pos = (media(lista_pitch), media(lista_pitch), media(lista_heading)) # Calcolo deviazione standard devstd_pos = (dev_std(lista_heading), dev_std(lista_roll), dev_std(lista_pitch)) print("Acquisizione terminata") return mean_pos, devstd_pos -
when i call calcolo_position I pass to it calcolo_position(1). But i call the function more than one time.
i change another time the code but the same is the same.
this is my 'main'
and few comment before you can find the other function that use inside the function 'calcolo_position(1)'print("START ACQUISITION") print("Rilevazione posizione corretta") time.sleep(1) position_ok = [] position_ok = calcolo_position(6) mean_pos_ok = position_ok[0] print("media posizione corretta", mean_pos_ok[2]) dev_std_ok = position_ok[1] gc.collect() print("END FIRST ACQUISITION") time.sleep(2) print("SECOND AQUISITION ") time.sleep(1) position_no =[] position_no = calcolo_position(6) mean_pos_no = position_no[0] dev_std_no = position_no[1] gc.collect() print("END SECOND AQUISITION") time.sleep(1) print("START test pitch") time.sleep(1) acquisizione_interval_pitch(20, 1, mean_pos_ok, mean_pos_no, dev_std_no )` -
@vflorio94 said in Wipy 2.0 and save data on my pc, not in flash memory:
position_ok = calcolo_position(6)
If you run that line, will it ever return or just give the error?
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