Code: Select all
Traceback (most recent call last):
File "/home/pi/sketchbook/I2Ctalk04/I2Ctalk04.py", line 36, in <module>
readBunchOfData(4)
File "/home/pi/sketchbook/I2Ctalk04/I2Ctalk04.py", line 25, in readBunchOfData
myDataHere = readBlockData(numBytes)
File "/home/pi/sketchbook/I2Ctalk04/I2Ctalk04.py", line 17, in readBlockData
x = bus.read_i2c_block_data(address, 0, numBytes)
File "/usr/local/lib/python3.4/dist-packages/smbus2/smbus2.py", line 391, in read_i2c_block_data
ioctl(self.fd, I2C_SMBUS, msg)
OSError: [Errno 121] Remote I/O errorHere is my code for the Pi:
Code: Select all
from smbus2 import SMBus
import time
bus = SMBus(1)
address = 0x04
def writeNumber(value):
bus.write_byte(address, value)
return -1
def readNumber():
number = bus.read_byte(address)
return number
def readBlockData(numBytes):
res3 = []
x = bus.read_i2c_block_data(address, 0, numBytes)
res3.extend(x)
return res3
def readBunchOfData(numBytes):
# Send number of bytes we are requesting
writeNumber(numBytes)
# Receive data
myDataHere = readBlockData(numBytes)
# Show what we've got
print ("We received ", numBytes, " of data")
for i in range(0, numBytes):
print (myDataHere[i])
while True:
# For now, hard-code 4 bytes of data
print ()
print ("We are requesting ", 4, " bytes of data")
readBunchOfData(4)
print ()
Code: Select all
#include <Wire.h>
#define SLAVE_ADDRESS 0x04
int number = 0;
int dataNo = 0;
void setup() {
Serial.begin(9600);
Wire.begin(SLAVE_ADDRESS);
Wire.onReceive(receiveData);
Wire.onRequest(sendData);
Serial.println("Ready!");
}
void loop() {
doingSomething(10);
}
void doingSomething(int loops) {
for (int i = 0; i<loops; i++) {
Serial.print("I'm doing something else...");
Serial.println(i);
delay(50);
}
}
void receiveData(int byteCount) {
while(Wire.available()) {
number = Wire.read();
if (dataNo == 0) {
// dataNo, so this is how many bytes to send - currently hard-coded at 4
dataNo = number;
}
else {
// We should not get here
Serial.println("We got to hole 1");
}
}
}
void sendData() {
byte output[] = {0x01,0x02,0x03,0x04}; // This is just some sample data for testing
Wire.write(output, 4);
dataNo = 0;
}
Now I have an 8ch constant current PCB handmade (14 x 16 cm) drilled (416 holes/vias) and over 200 components ready to go and now the two "hearts" of the system can't communicate back to the brain (pi) but can receive 5 bytes just fine from pi. I have given up on Wire to send multi-byte and even single byte back to pi. Even tried a FOR loop iterating through 12 bytes representing the 5 analog readings, the slave address and a digital input monitoring the output of a mosfet for a water pump.