I'm sending bits as LED blinks from one Pi Pico, and using another Pico to receive voltage from a photodiode and read the bits.
When sending/receiving from the same PiPico, it works accurately at 60us a bit. However, when sending from one pico and receiving from a second pico, I can only send/receive bits accurately at 0.1s a bit. If I move to sending/receiving at 0.01s, I start losing information. This leads me to believe my issue is with the clocks or sampling rates on the two pipicos, that they are slightly different.
Is there a way to synchronize two pipico clocks using Thonny/Micropython?
Code for Pico #1 sending blinks/bits:
led=Pin(13,Pin.OUT) #Led to blink
SaqVoltage = machine.ADC(28) #receive an input signal, when over a certain voltage, send the time using bits
#Ommitted code here to grab first low voltage values from SaqVoltage signal and use to determine if there is a high voltage received, when high voltage is received, send "hi" in led bits
#More omitted calibration code here for led/photodiode
hi = "0110100001101001"
while True:
SaqVoltage_value = SaqVoltage.read_u16()*3.3 / 65536 #read input signal to see if high voltage is sent
finalBitString = ""
if SaqVoltage_value > saQCutOff: #high voltage found, send "hi" sequence
finalBitString = #hi plus some start/stop sequences
for i in range (0, len(finalBitString)):
if finalBitString[i]=="1":
led(1)
elif finalBitString[i]=="0":
led(0)
utime.sleep(.01)
Code for Pico#2 receiving bits:
SaqDiode = machine.ADC(28) #read photodiode
#ommitted code here to calibrate leds/photodiodes
startSeqSaq = []
wordBits=[]
while True:
utime.sleep(.01) #sample diode every 0.01 seconds
SaqDiode_value = SaqDiode.read_u16()*3.3 / 65536
if (saqDiodeHi - saqCutOff <= SaqDiode_value): #read saq diode and determine 1 or 0
bit=1
elif (SaqDiode_value <= saqDiodeLo + saqCutOff):
bit=0
if len(startSeqSaq)==10: #record last 10 received bits to check if start sequence
startSeqSaq.pop(0)
startSeqSaq.append(bit)
elif len(startSeqSaq)<10:
startSeqSaq.append(bit)
if startSeqSaq == startSeq: #found start sequence, start reading bits
while True:
utime.sleep(.01)
SaqDiode_value = SaqDiode.read_u16()*3.3 / 65536
if (saqDiodeHi - saqCutOff <= SaqDiode_value):
bit=1
wordBits.append(bit)
elif (SaqDiode_value < saqDiodeLo + saqCutOff):
bit=0
wordBits.append(bit)
if len(wordBits)>10: #check for stop sequence
last14=wordBits[-10:]
else:
last14 = []
if last14==endSeq:
char = frombits(wordBits[:-10])
wordBits=[]
print("Function Generator Reset Signal Time in ms from Start: ", char)
break
Related
I would like to get synchronised timings and number of triggers for each single pulse sent by the 7T MRI scanner together with each single SPACEBAR keypress as a participant’s response when particular letters (A, B, C, X, Y) are presented on the screen, also the stimulus start time with each corresponding trigger.
So far I have added a “Waiting for scanner” routine where I get the first pulse via USB connected NNL Synbox saved in the .csv data file but I want to save each single pulse (TR) and timings. Triggers are automatically emulated as letter ‘s’ sent by the NNL Synbox.
# Code component: Creat routine "Wait for Scanner"
text_wait = visual.TextStim(win=win, name='text_wait',
text='Waiting for scanner...',
font='Arial',
pos=(0, 0), height=0.8, wrapWidth=None, ori=0,
color='white', colorSpace='rgb', opacity=1,
languageStyle='LTR',
depth=0.0);
#Set first MR Trigger
mr_trigger_number = [] # list for triggers
mr_trigger_time = [] # list for time of each trigger
ScannerKeyboard = keyboard.Keyboard() # set keyboard
count_mr_trigger = 0 # counts amount of MR scanner trigger, starts with zero
start_trigger = ScannerKeyboard.getKeys(keyList=['s'], waitRelease = False) # experiment starts with MR Scanner "s"
# Draw waiting Screen until "s" is sent from NNL Syncbox
while len(start_trigger) == 0: # if no trigger was sent show:
text_wait.draw() # Text "Waiting for scanner"
win.flip()
start_trigger = ScannerKeyboard.getKeys(keyList=['s'], waitRelease = False) # show text_wait until one "s" was received
# Get timing information and store trigger number
onset = core.getTime() # get Onset time of trigger
count_mr_trigger = count_mr_trigger + 1 # count MR Scanner trigger, add "1!
# Save time and number of MR Trigger
thisExp.addData('MR_trigger_time',onset) # save trigger time of onset
thisExp.addData('MR_trigger_number',count_mr_trigger)
And also I used the following code component in > Each Frame tab of 2 trials conditions to save the stimuli onset timings when a pulse 's' is received. This works fine but stimulus start time > stimulus_start_time = globalClock.getTime() - mr_trigger_time is saved based on first pulse only as I am unable to save each pulse timings.
#save stimulus onset time for two types of trial conditions
if trials.thisN == 0 and frameN == 0:
loop_start_time = globalClock.getTime() - mr_trigger_time
elif frameN == 1:
stimulus_start_time = globalClock.getTime() - mr_trigger_time
# store the data:
thisExp.addData('stimulus_start_time', stimulus_start_time)
if trials_2.thisN == 0 and frameN == 0:
loop_start_time = globalClock.getTime() - mr_trigger_time
elif frameN == 1:
stimulus_start_time = globalClock.getTime() - mr_trigger_time
# store the data:
thisExp.addData('stimulus_start_time', stimulus_start_time)
However, I want to record and save timings of each trigger pulse when a SPACEBAR response is pressed on a target letter (stimulus) by a participant, to compare the timings with accuracy and reaction times of the task with each corresponding trigger timings.
I would really appreciate your valuable suggestions on how to work around this, as I am quite new to the PsychoPy. I also posted to the PsychoPy forum but haven't got any update so far.
Thanks in advance!
I'm trying to make a serial communication between two ESP8266 Wifi chips.
To start, I tried sending a sample data 10 times in a for loop. Here is the code:
Transmiter:
for Packets = 1 : 10
SendData(client,Data(Packets));
end
Receiver:
Packets = 1
while(1)
Data(Packets) = ReceiveData(Server);
Packets = Packets + 1;
if (packets == 10)
break
end
end
it works good. The problem is when I want to send data with some delays, the transmitter should connect to receiver again and the server (receiver) receives some data indicating that connection is made again.
The received Buffer should be:
+IPD,0,1024:ùüþþþýýþþÿÿûûýþýûúþÿúóýÿþþþþþýúøûýþ...
but after reconnecting the received Buffer is:
0,CLOSED %Receiver Prompt, disconnected from Transmiter
0,CONNECT %Receiver Prompt,connected to Transmiter
+IPD,0,1024:ùüþþþýýþþÿÿûûýþýûúþÿúóýÿþþþþþýúøûýþ...
The remaining part of data will be read in next packet and same for next packets.
what should I do to receive just the data?
The send and receive functions:
function ReceivedBuffer = ReceiveData(SerialPort)
ReceivedBuffer = fread(server,1038); %Size data = 1038 Bytes
end
function SendData(SerialPort,Data)
fwrite(SerialPort,Data);
end
I'm trying to set up an interrupt-handler in my driver for DM6446 GPIO BANK 0 interrupt.But request_irq returns -22.I know the Interrupt number for GPIO BANK-0 from the data sheet which states it to be 56.Following are the settings for GPIO in my code.I want to get interrupt on GPIO-10.
while((REG_VAL(PTSTAT) & 0x1) != 0); // Wait for power state transtion to finish
REG_VAL(MDCTL26) = 0x00000203; //To enable GPIO module and EMURSITE BIT as stated in sprue14 for state transition
REG_VAL(PTCMD) = 0x1; // Start power state transition for ALWAYSON
while((REG_VAL(PTSTAT) & 0x1) != 0); // Wait for power state transtion to finish
REG_VAL(PINMUX0) = REG_VAL(PINMUX0) & 0x80000000; //Disbale other Functionlaity on BANK 0 pins
printk(KERN_DEBUG "I2C: PINMUX0 = %x\n",REG_VAL(PINMUX0));
REG_VAL(DIR01) = REG_VAL(DIR01) | 0xFFFFFFFF; //Set direction as input for GPIO 0 and 10
REG_VAL(BINTEN) = REG_VAL(BINTEN) | 0x00000001; //Enable Interrupt for GPIO Bank 0
REG_VAL(SET_RIS_TRIG01) = REG_VAL(SET_RIS_TRIG01) | 0x00000401; // Enable rising edge interrupt of GPIO BANK 0 PIN 0 PIN 10
REG_VAL(CLR_FAL_TRIG01) = REG_VAL(CLR_FAL_TRIG01) | 0x00000401; // Disable falling edge interrupt of Bank 0
Result = request_irq(56,Gpio_Interrupt_Handler,0,"gpio",I2C_MAJOR);
if(Result < 0)
{
printk(KERN_ALERT "UNABLE TO REQUEST GPIO IRQ %d ",Result);
}
A little help shall be appreciated.
Thank you.
I have tried the gpio_to_irq as well for PIN-10 of BANK-0 but it returns irq no to be 72 but DM6446 has interrupt number upto 63 only in Data sheet.
I got it. If i use gpio_to_irq, It will return a valid IRQ number but different than the interrupt number(which i guess is also called IRQ number) specified in data sheet of Processor.If I see the /proc/interrupts, it will have an entry of that IRQ returned form gpio_to_irq but under GPIO type not the processor's Interrupt controller, which in my case for ARM shall be AINTC.All other interrupts are of AINTC type.
Moreover, Even if request_irq succeeds with interrupt number stated in data sheet,/proc/stat will report interrupts at both IRQ numbers i.e. AINTC and GPIO type.
I have connected my RPI and atmega328 together in order to control the start of an event on my arduino. In order to do so, GPIO 25 (RPI) is connected directly to pin7 (Arduino PD7). I've got a python script on the RPI witch set the GPIO 25 to high then back to LOW:
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(25, GPIO.OUT)
GPIO.output(25, 1)
#Do some stuff
GPIO.output(25, 0)
The arduino is waiting in a loop for either a physical button to be pressed or the pin7 to be set to HIGH by the RPI:
const int interrupt = 7;
const int button = 13;
const int led = 9;
void setup() {
Serial.begin(9600);
pinMode(interrupt, INPUT);
pinMode(button,INPUT);
pinMode(led, OUTPUT);
digitalWrite(led, LOW);
}
void loop() {
bool on = false;
bool buttonOn = false;
while (!on || !buttonOn) {
on = digitalRead(interrupt);
buttonOn = digitalRead(button);
digitalWrite(led, LOW);
}
digitalWrite(led, HIGH);
delay(1000);
}
Now unfortunately this doesn't work. I have checked the logic level of the atmega328 (https://learn.sparkfun.com/tutorials/logic-levels) and it seems that 3.3V is good enough for HIGH signal.
Am I missing something with the pull up /pull down resistance? I know the PD7 on the atmega is specified as follow:
Port D is an 8-bit bi-directional I/O port with internal pull-up
resistors (selected for each bit). The Port D output buffers have
symmetrical drive characteristics with both high sink and source
capability. As inputs, Port D pins that are externally pulled low will
source current if the pull-up resistors are activated. The Port D pins
are tristated when a reset condition becomes active, even if the clock
is not running.
EDIT:
I have done more testing and I am getting the HIGH or LOW value correctly. It seems that the issue comes from the:
while ((!on) || (!buttonOn)) {
Is there an issue with Arduino and the OR operator in a while loop? Even when one condition is true and the other one is false, it never goes out of the loop.
while ((!on) || (!buttonOn)) {
}
That loop will run as long as one of the variables is false.
Yesterday I was for some reason thinking that you were reading the interrupt pin twice when reading your code.
3.3 v output should be ok to turn the Arduino input high.
You can have a wiring problem or your raspberry pi can be so fast that the arduino misses the pulse.
Change your program on the raspberry pi to leave the output high for so long (e.g. 10) seconds that you can measure it with a multimeter to see that you are setting the right pin.
Does the Arduino now see the input?
I'm trying to read the data from the COM3 port.
I'm using this code:
in = fscanf(s);
if(in == 'A')
fclose(s);
break;
end
The problem is that when no data is sent to the com3 port, the fscanf() will wait for a certain time interval and then give a timeout.
Is there a way to read data only when it is present?
Read only when data present
You can read out the BytesAvailable-property of the serial object s to know how many bytes are in the buffer ready to be read:
bytes = get(s,'BytesAvailable'); % using getter-function
bytes = s.BytesAvailable; % using object-oriented-addressing
Then you can check the value of bytes to match your criteria. Assuming a char is 1 byte, then you can check for this easily before reading the buffer.
if (bytes >= 1)
in = fscanf(s);
% do the handling of 'in' here
end
Minimize the time to wait
You can manually set the Timeout-property of the serial object s to a lower value to continue execution earlier as the default timeout.
set(s,'Timeout',1); % sets timeout to 1 second (default is 10 seconds)
Most likely you will get the following warning:
Unsuccessful read: A timeout occurred before the Terminator was
reached..
It can be suppressed by executing the following command before fscanf.
warning('off','MATLAB:serial:fscanf:unsuccessfulRead');
Here is an example:
s = serial('COM3');
set(s,'Timeout',1); % sets timeout to 1 second (default is 10 seconds)
fopen(s);
warning('off','MATLAB:serial:fscanf:unsuccessfulRead');
in = fscanf(s);
warning('on','MATLAB:serial:fscanf:unsuccessfulRead');
if(in == 'A')
fclose(s);
break;
end