MSP430FG6626: help in having ADC example working on EVM

I would suggest you to refer to these code examples as they are dedicated for this device.

I did use the code msp430fg662x_ctsd16_03.c 

The setup is as follows:

                   MSP430FG662x
//                -----------------------
//           /|\  |                          |
//            |   |                          |
//             --|RST                   |
// (0.2VDC)|                          |
// Vin1+ -->| A0.0+     VREF| ---+  (0.5VDC)
// Vin1- --> | A0.0-                |     |
// (GND)    |                          |   -+- 1nF
//                |                         |   -+-
//                |                         |    |
//                |                AVss |---+
//

these are the results I am getting

results = [30655,30656,30682,30768,30744, 30393, 29675, 28908]

when I run the program again i get the following:

results = [30364,30315,30207,30130,30074, 29978, 29915, 29870]

Every time I rerun, I get a different value

If I increase the DC input to 0.3VDC, this is what I get:

results = [27187,27189,27192,27240,27283, 27311, 27316, 27251]

after rerun:

results = [29543,28797,28107,27437,26649, 25935, 25517, 25013]

Why the values are random?

I cant change the Vref. How could you change the Vref? Is it by changing the C6 and C14 on the board?

It used internal reference. 

    CTSD16CTL = CTSD16REFS;                 // Internal ref

Can you connect Vin1+ and Vin1- together. To check if the value goes to 0.

Please remember the debug noise will affect the detection result.

Connected Vin1+ (Pin 4) to Vin- (pin 5), also getting random values that change every time I run the code.

Can you share your used code, I can help you test it on my side.

HI Eason , 

we started w  m  testing example  cstd16_ex2_singleChSingleConvPolling project      , any example out of the chip colleteral yuo can test  adn show working can help 

please consider  we are working w the ZIF board  as  specidife in first message    - so great if yuo can have something workng there  

thank you 

BR

Carlo

please look at my previous reply: 

I did use the code msp430fg662x_ctsd16_03.c 

The setup is as follows:

                   MSP430FG662x
//                -----------------------
//           /|\  |                          |
//            |   |                          |
//             --|RST                   |
// (0.2VDC)|                          |
// Vin1+ -->| A0.0+     VREF| ---+  (0.5VDC)
// Vin1- --> | A0.0-                |     |
// (GND)    |                          |   -+- 1nF
//                |                         |   -+-
//                |                         |    |
//                |                AVss |---+
//

these are the results I am getting

results = [30655,30656,30682,30768,30744, 30393, 29675, 28908]

when I run the program again i get the following:

results = [30364,30315,30207,30130,30074, 29978, 29915, 29870]

Every time I rerun, I get a different value

If I increase the DC input to 0.3VDC, this is what I get:

results = [27187,27189,27192,27240,27283, 27311, 27316, 27251]

after rerun:

results = [29543,28797,28107,27437,26649, 25935, 25517, 25013]

Why the values are random?

I cant change the Vref. How could you change the Vref? Is it by changing the C6 and C14 on the board?"

Hi Yaser , 

shared project and  results  , please kindly confirm it is working on your side too

thank you 

BR
Carlo

As we move this thread to offline, I will close this thread.

Thank you Carlo,

I can make some measurements now. However, I want to know the following:

What is the default Vref on the board as is?

According to my calculations, the ref V is about 0.65V, what I measure across C14 is .55V.

Could you explain the difference?

Thanks

Yaser

Hi Yaser,

The reference voltage is 1.2V.

Here is the example:

If the input voltage is 0.5V. And the data format is 2s component.

Measurement = 37702B h / 7FFFFFFh *1.2 = 0.52 V

Regards,

Zoey