I configured the ADC for 3 instances/3 analog inputs:
In APP_STATE_INIT i enable and start ADC:
case APP_STATE_INIT:
{
bool appInitialized = true;
if (appInitialized)
{
appData.state = APP_STATE_SERVICE_TASKS;
}
DRV_TMR0_Start(); // Start the Timers
DRV_ADC_Initiallize();
DRV_ADC_Enable();
}
Now in this test application I want to read the ports. But in this specific case I want to read the Channel Instance 0 and Instance 1 (each instance will have changing values that can be configured with a dil-switch):
case APP_STATE_SERVICE_TASKS:
{
DRV_ADC_Start();
//Provide Delay
int i;
for(i=0;i <1000;i++)
{
}
DRV_ADC_Stop();
while(!DRV_ADC_SamplesAvailable()) {}
printf("addr: %d \r\n",DRV_ADC_SamplesRead(i)>>2);
break;
}
This is alternating between values when it's not supposed. I configured 3 channels so I suppose it's alternating between them, how to choose a specific channel?
What needs to be done here?
The pins are configured this way:
Basically what i would like is something like we have in the pic32 family reference manual in Example 17-1: Converting 1 Channel, Manual Sample Start, Manual Conversion Start Code
AD1PCFG = 0xFFFB; // PORTB = Digital; RB2 = analog
AD1CON1 = 0x0000; // SAMP bit = 0 ends sampling ...
// and starts converting
AD1CHS = 0x00020000; // Connect RB2/AN2 as CH0 input ..
// in this example RB2/AN2 is the input
AD1CSSL = 0;
AD1CON3 = 0x0002; // Manual Sample, Tad = internal 6 TPB
AD1CON2 = 0;
AD1CON1SET = 0x8000; // turn ADC ON
while (1) // repeat continuously
{
AD1CON1SET = 0x0002; // start sampling ...
DelayNmSec(100); // for 100 mS
AD1CON1CLR = 0x0002; // start Converting
while (!(AD1CON1 & 0x0001)); // conversion done?
ADCValue = ADC1BUF0; // yes then get ADC value
}
Where we can choose between channel 14,15 and 22.
Note: It seems to work well if i only have 1 instance running. This probably has something to do with the multiplex which i dont fully understand.
Using:
- MPLAB Harmony v2
- MPLAB X IDE v5.20
- PIC32MX470F512L configured to run at 32MHz
EDIT:
After applying @pm101 answer it still keeps reading what is not supposed.
As we can see on termite:
Doing the other solution:
int conversion;
uint8_t j = 0;
while(j++<3) {
DRV_ADC_Start();
//Provide Delay
int i;
for(i=0;i <1000;i++)
{
}
while(!DRV_ADC_SamplesAvailable()) {}
}
DRV_ADC_Stop();
conversion = DRV_ADC_SamplesRead(val)>>2;//Val will be the sample we want to read.
return (unsigned char)conversion;
The value is always the same?
TEST 19/06
I did the following to my ADC_GetConversion function:
unsigned char ADC_GetConversion(uint8_t val){
int conversion;
switch(val) {
case 0:
AD1CSSLCLR = 0x00000000;
AD1CSSLSET = 0x00004000;//AN14
break;
case 1:
AD1CSSLCLR = 0x00000000;
AD1CSSLSET = 0x00008000;//AN15
break;
}
DRV_ADC_Start();
//Provide Delay
int i;
for(i=0;i <1000;i++)
{
}
while(!DRV_ADC_SamplesAvailable()) {}
DRV_ADC_Stop();
conversion = DRV_ADC_SamplesRead(0)>>2;
return (unsigned char)conversion;
}
then on a while cycle i do:
printf("addr%d: %d \r\n",14,decode_switch_conversion(ADC_GetConversion(0)));
printf("addr%d: %d \r\n",15,decode_switch_conversion(ADC_GetConversion(1)));
Context: The decode_switch_conversion converts these adc tension conversion to the correspondent value that was coded in a four switch (only switch number 1 down means we want the value 1) . AN14 there is connected a 4 switch, and the AN15 there is another 4 four switch.
But those 2 prints get the value switched for both?
The result i get from termite:
In reality i have 1 for the switch of AN14 and 3 for the switch of AN15.
But if i only read 1 channel and never do the lines AD1CSSLCLR and AD1CSSLSET the values are good!
