Hi
I've been trying to change the external reference voltage (VREF-HI) for the ADC, on my F28035 DIMM controlCard with the Experimenter Kit
Inside InitAdc, of DSP2803x_Adc.c file I've added
AdcRegs.ADCCTL1.bit.ADCREFSEL = 1;
So the complete code is:
EALLOW;
AdcRegs.ADCOFFTRIM.bit.OFFTRIM = 0x1DA;
AdcRegs.ADCCTL1.bit.ADCBGPWD = 1; // Power ADC BG
AdcRegs.ADCCTL1.bit.ADCREFPWD = 1; // Power reference
AdcRegs.ADCCTL1.bit.ADCPWDN = 1; // Power ADC
AdcRegs.ADCCTL1.bit.ADCENABLE = 1; // Enable ADC
AdcRegs.ADCCTL1.bit.ADCREFSEL = 1;
EDIS;
And I've switched the pin SW3 in the "upward" position, on my controlCard.
"Position 1 controls VREF-HI, the value that the ratiometric ADC will convert as the maximum 12-bit value, 0X0FFF. In the downward position, VREF-HI will be connected to 3.3V. In the upward position, VREf-HI will be connected to pin 66 of the DIMM100-socket."
It seems to change for an external reference of 2.048V, with my experimenter kit.
But I would like to change it for an external reference of 1.024V
According to the file "An Overview of Designing Analog Interface With TMS320F28xx/28xxx DSCs", that's something I can do
For F280xx devices: The ADCREFIN voltage (1.024 V, 1.500 V, or 2.048 V) replaces the internal BG voltage, which is then used to generate the signals REFP/REFM that are used by the ADC during the conversion process.
How can I achieve it?
Thanks!
