Hello,
I try to migrade from R3 Uno to R4 minima.
And I am struggelin with I2C communication.
Situation:
1 nano board used as a slave send a struct of arround 64 byte to the master R4 minima.
The "buffer size" of the "Wire.h" and the "twi.h" library is changed to "64" (nano side)
the struct looks like the following:
struct Waagen{
char item1[20]; //20 byte
char item2[20]; // 20 byte
uint8_t minPcs; //1 byte
int pcs; //2byte
uint8_t calcPcs; //1byte
uint8_t waageID; //1byte
uint8_t whatToDo; // 1byte
}
on the master side i receive the struct until "Waagen.minPcs". The remaining values are 255 or -65504...
Here the serial output from the master side
22:20:41.874 -> item1: 476288EI08020
22:20:41.874 -> item2: 123ABC
22:20:41.874 -> minPcs: 150
22:20:41.874 -> pcs: -65504
22:20:41.874 -> calcPcs: 255
22:20:41.874 -> waageID: 255
22:20:41.874 -> whatToDo: 255
the stream on the master I receive as the following
//Just a sample...
struct Waagen waage;
Wire.readBytes((byte*)&waage, sizeof waage);
The "Wire.h" library on the R4 looks diffrent, but there is a I2C_BUFFER_LENGTH too. It is by default "255".
I used 4k7 Pullups on the I2C line. no change
Do you know where I have to poke?
Thank you for your time in advance.
regards
Daniel
