/*JSON{
"type" : "method",
"class" : "I2C",
"name" : "readFrom",
"generate" : "jswrap_i2c_readFrom",
"params" : [
["address","JsVar","The 7 bit address of the device to request bytes from, or an object of the form `{address:12, stop:false}` to send this data without a STOP signal."],
["quantity","int32","The number of bytes to request"]
],
"return" : ["JsVar","The data that was returned - as a Uint8Array"],
"return_object" : "Uint8Array"
}
Request bytes from the given slave device, and return them as a Uint8Array (packed array of bytes). This is like using Arduino Wire's requestFrom, available and read functions. Sends a STOP
*/
JsVar *jswrap_i2c_readFrom(JsVar *parent, JsVar *addressVar, int nBytes) {
IOEventFlags device = jsiGetDeviceFromClass(parent);
if (!DEVICE_IS_I2C(device)) return 0;
bool sendStop = true;
int address = i2c_get_address(addressVar, &sendStop);
if (nBytes<=0)
return 0;
if ((unsigned int)nBytes+256 > jsuGetFreeStack()) {
jsExceptionHere(JSET_ERROR, "Not enough free stack to receive this amount of data");
return 0;
}
unsigned char *buf = (unsigned char *)alloca((size_t)nBytes);
jshI2CRead(device, (unsigned char)address, nBytes, buf, sendStop);
JsVar *array = jsvNewTypedArray(ARRAYBUFFERVIEW_UINT8, nBytes);
if (array) {
JsvArrayBufferIterator it;
jsvArrayBufferIteratorNew(&it, array, 0);
unsigned int i;
for (i=0;i<(unsigned)nBytes;i++) {
jsvArrayBufferIteratorSetByteValue(&it, (char)buf[i]);
jsvArrayBufferIteratorNext(&it);
}
jsvArrayBufferIteratorFree(&it);
}
return array;
}
void jswrap_spi_send_cb(int c, jswrap_spi_send_data *data) {
int result = data->spiSend(c, &data->spiSendData);
if (c>=0) data->txAmt++;
if (result>=0) {
jsvArrayBufferIteratorSetByteValue(&data->it, (char)result);
jsvArrayBufferIteratorNext(&data->it);
data->rxAmt++;
}
}
/**
* Send a single byte to the SPI device, used ad callback.
*/
void jswrap_spi_send_cb(
int c, //!< The byte to send through SPI.
jswrap_spi_send_data *data //!< Control information on how to send to SPI.
) {
// Invoke the SPI send function to transmit the single byte.
int result = data->spiSend(c, &data->spiSendData);
if (c>=0) data->txAmt++;
if (result>=0) {
jsvArrayBufferIteratorSetByteValue(&data->it, (char)result);
jsvArrayBufferIteratorNext(&data->it);
data->rxAmt++;
}
}
/*JSON{
"type" : "method",
"class" : "OneWire",
"name" : "read",
"generate" : "jswrap_onewire_read",
"params" : [["count","JsVar","(optional) The amount of bytes to read"]],
"return" : ["JsVar","The byte that was read, or a Uint8Array if count was specified and >=0"]
}
Read a byte
*/
JsVar *jswrap_onewire_read(JsVar *parent, JsVar *count) {
Pin pin = onewire_getpin(parent);
if (!jshIsPinValid(pin)) return 0;
if (jsvIsNumeric(count)) {
JsVarInt c = jsvGetInteger(count);
JsVar *arr = jsvNewTypedArray(ARRAYBUFFERVIEW_UINT8, c);
if (!arr) return 0;
JsvArrayBufferIterator it;
jsvArrayBufferIteratorNew(&it, arr, 0);
while (c--) {
jsvArrayBufferIteratorSetByteValue(&it, (char)OneWireRead(pin, 8));
jsvArrayBufferIteratorNext(&it);
}
jsvArrayBufferIteratorFree(&it);
return arr;
} else {
return jsvNewFromInteger(OneWireRead(pin, 8));
}
}