/*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_i2c_writeTo(JsVar *parent, JsVar *addressVar, JsVar *args) {
IOEventFlags device = jsiGetDeviceFromClass(parent);
if (!DEVICE_IS_I2C(device)) return;
bool sendStop = true;
int address = i2c_get_address(addressVar, &sendStop);
size_t l = (size_t)jsvIterateCallbackCount(args);
if (l+256 > jsuGetFreeStack()) {
jsExceptionHere(JSET_ERROR, "Not enough free stack to send this amount of data");
return;
}
unsigned char *data = (unsigned char *)alloca(l);
jsvIterateCallbackToBytes(args, data, l);
jshI2CWrite(device, (unsigned char)address, l, data, sendStop);
}
/*JSON{
"type" : "method",
"class" : "I2C",
"name" : "setup",
"generate" : "jswrap_i2c_setup",
"params" : [
["options","JsVar",["An optional structure containing extra information on initialising the I2C port","```{scl:pin, sda:pin, bitrate:100000}```","You can find out which pins to use by looking at [your board's reference page](#boards) and searching for pins with the `I2C` marker. Note that 400000kHz is the maximum bitrate for most parts."]]
]
}
Set up this I2C port
If not specified in options, the default pins are used (usually the lowest numbered pins on the lowest port that supports this peripheral)
*/
void jswrap_i2c_setup(JsVar *parent, JsVar *options) {
IOEventFlags device = jsiGetDeviceFromClass(parent);
if (!DEVICE_IS_I2C(device)) return;
JshI2CInfo inf;
jshI2CInitInfo(&inf);
if (jsvIsObject(options)) {
inf.pinSCL = jshGetPinFromVarAndUnLock(jsvObjectGetChild(options, "scl", 0));
inf.pinSDA = jshGetPinFromVarAndUnLock(jsvObjectGetChild(options, "sda", 0));
JsVar *v = jsvObjectGetChild(options, "bitrate", 0);
if (v)
inf.bitrate = jsvGetIntegerAndUnLock(v);
}
jshI2CSetup(device, &inf);
// Set up options, so we can initialise it on startup
if (options)
jsvUnLock(jsvSetNamedChild(parent, options, DEVICE_OPTIONS_NAME));
else
jsvRemoveNamedChild(parent, DEVICE_OPTIONS_NAME);
}
void doMeasurement() {
enableDASH();
JsVar *i2c1 = jspGetNamedField(execInfo.root, "I2C1", false);
IOEventFlags device = jsiGetDeviceFromClass(i2c1);
if (!DEVICE_IS_I2C(device)) {
blink(PIN_RED, 100);
return;
}
jsvUnLock(i2c1);
unsigned char dataPtr[2];
dataPtr[0] = CMD_MEASURE_TEMPERATURE_HOLD;
jshI2CWrite(device, (unsigned char)(CMD_TEMP_ADDR), 1, (unsigned char*)dataPtr, true);
int i = 0;
for (i=0; i<2; i++) { dataPtr[i] = 0; }
jshI2CRead(device, (unsigned char)CMD_TEMP_ADDR, 2, (unsigned char*)dataPtr, true);
int temp = ((dataPtr[0] * 256) + dataPtr[1]);
/// http://www.silabs.com/Support%20Documents/TechnicalDocs/Si7050-1-3-4-5-A20.pdf#page=14
JsVarFloat realTemp = ((175.72f * temp) / 65536.0f) - 46.85f;
char temperatureBuffer[6] = {0};
ftoa_bounded(realTemp, temperatureBuffer, 5);
temperatureBuffer[5] = '\0';
char serialNumber[SERIAL_LEN] = {0};
getSerial(serialNumber, SERIAL_LEN);
/// Generate the JSON that we send to gateway skyand then to API{\"nodeSerial\":\"%s\",\"channel\":\"temp\",\"value\":\"%s\",\"metric\":\"c\"}');", serialNumber + SERIAL_OFFSE
jsvUnLock(messageVar);
if (doTimeout) { //regular message
messageVar = jsvVarPrintf("{\"ns\":\"%s\",\"ch\":\"t\",\"v\":\"%s\",\"m\":\"c\"}", serialNumber + SERIAL_OFFSET, temperatureBuffer);
} else { //this only happens if we forced the read
messageVar = jsvVarPrintf("{\"ns\":\"%s\",\"ch\":\"t\",\"v\":\"%s\",\"m\":\"c\",\"f\":\"y\"}", serialNumber + SERIAL_OFFSET, temperatureBuffer);
}
WDEBUG("sending on DASH: "); WDEBUGSTRVAR(messageVar); WDEBUGLN("");
JsVar *serial = jspGetNamedField(execInfo.root, SERIAL1_DASH7, false);
jswrap_serial_print(serial, messageVar);
jsvUnLock(serial);
transmittingData = true; // see jswrap_wice_idle
}
