RFduinoBLE_onReceive when sending bytearray

Question

I'm attempting to send 8-bit byteArrays to an rfduino.

In the sketch, I got

void RFduinoBLE_onReceive(char *data, int len) {
   int firstbyte = data[0];
   Serial.println(firstbyte)
}

This works fine if the firstbyte is over 32. But if I'm sending a byteArray of [13, ...], firstbyte is parsed as 0.

I think I understand why (?): RFduinoBLE parses incoming data as characters before sending it to this function, and bytes up to 32 are empty string.

So my question is: how can I use the RFduinoBLE-onReceive to read bytearrays with values below 32?

Answer 1

The following seems to work just fine:

void RFduinoBLE_onReceive(char *data, int length) {
    uint8_t firstbyte = data[0];
}

or for arrays

uint8_t getData[20];

void RFduinoBLE_onReceive(char *data, int length) {
    for (i = 0; i < length; i++) {
        getData[i] = data[i];
    }
}

Not quite sure what went right/wrong where, but I suspect either using int firstbyte instead of uint8_t firstbyte or casting uint8_t firstbyte = (uint8_t) data[0] did something I didn't expect.