raspi-gpio get 0-15 #get gpio assignments

cd /tmp
wget <https://project-downloads.drogon.net/wiringpi-latest.deb>
sudo dpkg -i wiringpi-latest.deb
gpio readall # get all the pins 

Rpi side

ser.write hangs with ttyAMA0

python hangs on serial write() - Raspberry Pi Forums

solution: avoid using ttyAMA0 for python and F28 communication

Code

Used pySerial for sending and receiving data using UART

ref:

Welcome to pySerial's documentation - pySerial 3.4 documentation

'''
UART communicate of F28379D and raspberry pi through python
ref: <https://pyserial.readthedocs.io/en/latest/shortintro.html>
Yixiao Liu 11/15/2022

ttyAMA1 has gpio0(pin27) as TX and gpio1(pin28) as RX
connected with SCID of F28(pin 9 RX, pin 10 TX)
run F28 code first
'''
import serial
import struct
from serial import Serial

# initialize the serial port
ser = serial.Serial("/dev/ttyAMA1", 115200) #Open port with baud rate

'''
1) Send "**" as header from pi to F28 and receive 10 floats F28 sends back
'''
# write header for F28 to send 10 floats
ser.write(str.encode('*')) 
ser.write(str.encode('*'))

# wait for 40 bytes(10 floats)
s = ser.read(40) # read 40 bytes
floats = struct.unpack('ffffffffff',s) # unpack 40 bytes as 10 floats
print(floats)

'''
2) Send "##" as header, then follow by 10 floats to F28
'''
# ser.write(str.encode('#')) 
# ser.write(str.encode('#'))
# for i in range(10):
#     ser.write(struct.pack('f',0.1*i + 0.234))

Explanation:

• Open port /dev/ttyAMA1 for UART communication, pins can be found with raspi-gpio get 0-15 and gpio readall

• ser.write is used for writing data to F28, ser.read is for reading data.

• struct is an easy way to pack the data into bytes or unpack the bytes into desired data types.

  struct - Interpret bytes as packed binary data - Python 3.11.0 documentation

  

Usage: