1 ACCEPTED SOLUTION
Accepted Solutions
Now I had a closer look in the registers. For my device the RM0440 is the right one. My ADC does not have an ADC_CHSELR Register.
- According to Figure 85, OPAMP3 is connected to Channel 18. The Other Inputs I use are Channel 3, 4, and 8.
- All the inputs are selected correctly as single-ended inputs. (DIFSEL=0)
- Channel Selection seems correct. This is given by SQR1. Bits SQ1 are 0x3 (Channel 3), Bits SQ2 are 0x4 (Channel 4), Bits SQ2 are 0x8 (Channel 8), and Bits SQ4 are 0x12 (Channel 18). Bits L are set to 0x03 (Corresponds to 4 conversions).
- All other Sequence Regsiters are 0x0
- Channel-wise programmable sampling time seems correct. SMP3, SMP4, SMP8, and SMP18 are set to 0x7 in SMPR1 and SMPR2.
- All other registers also seem ok to me,
I wonder a little bit what the second switch in figure 85 is about. As far as I understand, the channel select bits only control the switches on the right side in the following picture:
I wasn't able to find further information on this. According to table 201, the adc input is connected internally to the OPAMP3_VOUT when OPAINTOEN bit is set. Do you think that this might be the second switch? However, the bit is set in OPAMP3_CSR. So everything seems fine here.
I also read Chapter 11 about the periphals interconnect matrix. But unfortunately I did not find anything here (Some connections are disabled in low power modes, which I do not use).
I think so, swith is likely the same as shown in this picture:
I don't have G431, but I tested nucleo-G474re, and all perfectly works.
Setings:
/*OPA-3
0x12980145 0x12880000 0x11880000 0x12900000
*/
/*ADC-2
0x0000000B 0x00000010 0x10000005 0x80003003 0x00000000 0x07007E00 0x07000000 0x00000000
0x0FFF0000 0x00FF0000 0x00FF0000 0x00000000 0x122040C3 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000 0x00000000 0x00000037 0x00000000 0x00000000
ADC_SQR1:
Reg: 50000130 0001 0010 0010 0000 0100 0000 1100 0011 (0x122040C3)
ADC_SMPR1:
Reg: 50000114 0000 0111 0000 0000 0111 1110 0000 0000 (0x07007E00)
*/
Results with all 4 inputs in parallel with small DC voltage applyed:
PGA: 2
*0 113 116 117 228
PGA: 4
*0 116 104 113 455
PGA: 8
*0 119 111 119 908
PGA: 16
*0 116 115 113 1827
PGA: 32
*0 118 113 116 3646
PGA: 64
*0 115 104 117 4095
Here is the soft, generated by CubeMX but re-configured to run in arduino IDE:
void setup()
{
Serial.begin(115200);
in_String.reserve(200);
Serial.print(F("\n\n\tSketch: g474_pga32. Date: 13 sept. 2024"));
// SystemClock_Config();
Serial.print(F("\n\tSys_clock: "));
Serial.print(((uint32_t) SystemCoreClock /(float) 1000000.0), 3);
Serial.print(F(" MHz."));
Serial.print(F("\n\tcfg_Pins..."));
delay(100);
cfg_Pins1();
Serial.print(F("\tdone."));
Serial.print(F("\n\tDMA..."));
delay(100);
hadc2.Instance = ADC2;
my_DMA_Init( &hadc2 );
Serial.print(F("\tdone."));
Serial.print(F("\n\tADC..."));
delay(100);
my_ADC2_Init();
Serial.print(F("\tdone."));
Serial.print(F("\n\topa3_config..."));
delay(100);
OPA_Config3();
pga_adjust(pga_input);
Serial.print(F("\tdone."));
Serial.print("\n\tADC_start_dma.");
delay(100);
if (HAL_ADC_Start_DMA(&hadc2, (uint32_t *)inp_1, (2 * INP_BUFF)) != HAL_OK) {
Error_Handler();
Serial.print("\n\tError-start-dma.");
}
else
Serial.print("\tDone.");
Serial.print(F("\n\tSetup complete."));
}
void cfg_Pins1(void)
{
GPIO_InitTypeDef GPIO_InitStruct = { 0, 0, 0, 0, 0};
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
/**ADC2 GPIO Configuration
PC2 ------> ADC2_IN8
PA6 ------> ADC2_IN3
PA7 ------> ADC2_IN4
*/
GPIO_InitStruct.Pin = GPIO_PIN_2;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/**OPAMP3 GPIO Configuration
PB13 ------> OPAMP3_VINP
*/
GPIO_InitStruct.Pin = GPIO_PIN_13;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
//DEBUG
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
}static void OPA_Config3( void )
{
hopamp3.Instance = OPAMP3;
// hopamp3.Init.PowerMode = OPAMP_POWERMODE_HIGHSPEED;
hopamp3.Init.PowerMode = OPAMP_POWERMODE_NORMALSPEED;
hopamp3.Init.Mode = OPAMP_PGA_MODE;
hopamp3.Init.NonInvertingInput = OPAMP_NONINVERTINGINPUT_IO1;
hopamp3.Init.InternalOutput = ENABLE;//DISABLE;
hopamp3.Init.TimerControlledMuxmode = OPAMP_TIMERCONTROLLEDMUXMODE_DISABLE;
hopamp3.Init.PgaConnect = OPAMP_PGA_CONNECT_INVERTINGINPUT_NO;
// hopamp3.Init.PgaConnect = OPAMP_PGA_CONNECT_INVERTINGINPUT_IO0_BIAS;
hopamp3.Init.PgaGain = OPAMP_PGA_GAIN_32_OR_MINUS_31;
//hopamp3.Init.PgaGain = OPAMP_PGA_GAIN_64_OR_MINUS_63;
hopamp3.Init.UserTrimming = OPAMP_TRIMMING_FACTORY;
if (HAL_OPAMP_Init(&hopamp3) != HAL_OK)
{
Error_Handler();
}
if (HAL_OPAMP_Start(&hopamp3) != HAL_OK)
{
Error_Handler();
}
}
void pga_adjust(uint16_t gain_set)
{
uint32_t reg_set = 0x00000001;
gain_set &= 0x0000007E;
if(gain_set == 2) reg_set = OPAMP_PGA_GAIN_2_OR_MINUS_1;
if(gain_set == 4) reg_set = OPAMP_PGA_GAIN_4_OR_MINUS_3;
if(gain_set ==
