Getting a "expected primary-expression before 'float'"

Projects Programming
1

Hi everyone!

I'm getting a "expected primary-expression before 'float'" message,

What does it mean by "primary expression?" The line in question is calling a function in a header file, which gives me a feeling of uncertainty and cloudy incomprehension.

any ideas?

void loop()
{
  metervoltage = analogRead(meterpin);
  doublemetervoltage = 2 * metervoltage;
  digitalcoeff = (5 / 1023);
  flowrate = 0.00488759 * doublemetervoltage; // 0.00488759=digitalcoeff;
dac_voltage = flowrate;
LTC2664_voltage_to_code(dac_voltage, float min_output, float max_output);
LTC2664_write(LTC2664_CS, LTC2664_CMD_WRITE_ALL_UPDATE_ALL, 0, dac_voltage);
2

Remove the float from

LTC2664_voltage_to_code(dac_voltage, float min_output, float max_output);

If you need to cast because the function expects floats, put braces around the float

LTC2664_voltage_to_code(dac_voltage, (float)min_output, (float)max_output);

If you get compiler warnings or errors after that, post your complete code. We have no idea what the types of the variables are or what your functions expect as parameters.

3

I'm trying to call a function in a header file using this line:

LTC2664_voltage_to_code(dac_voltage, float min_output, float max_output);

and I have no idea what a "primary-expression" is, or what it is reffering to. any ideas?

Thanks,

Justin

void loop()
{
  metervoltage = analogRead(meterpin);
  doublemetervoltage = 2 * metervoltage;
  digitalcoeff = (5 / 1023);
  flowrate = 0.00488759 * doublemetervoltage; // 0.00488759=digitalcoeff;
dac_voltage = flowrate;
LTC2664_voltage_to_code(dac_voltage, float min_output, float max_output);
LTC2664_write(LTC2664_CS, LTC2664_CMD_WRITE_ALL_UPDATE_ALL, 0, dac_voltage);

expected primary-expression before 'float'
4

If you're trying to cast min_output and max_output as floats, it needs to read as (float) min_output ...

5

You already had an answer in Getting a "expected primary-expression before 'float'" - Programming Questions - Arduino Forum.

Don't double post !!

6

Thanks everyone, for the help. Still learning stuff.

This is for a DAC, and it gets complicated very fast.