I'm trying to communicate between the STM32F107VC (master mode) and a TDC GP22 slave chip but came across this issue:I'm expecting to read 0x12 but i always get 0xFF, plese help me my email: [e-mail]

[aasil]

		 gp22_send_1byte(Power_On_Reset);
 HAL_Delay(1);
 gp22_wr_config_reg(0x81, reg_test); 
		 HAL_Delay(1);
 //gp22_send_1byte(init);
		 
 HAL_SPI_Transmit(&hspi3, &tx, 1, 1); //send tx=0xb5 opcode
 HAL_Delay(1);
		 HAL_SPI_Receive(&hspi3, &recive, 1, 1); // store in uint8_t rx
			 HAL_Delay(1);
		
		data_buf2 = (reg_test>>24)&0xff ;
		
		if(recive==data_buf2){
		 
			printf ("OK");
		 }
 else{
				 
					 printf ("NO");
				 } 
		
 HAL_Delay(50);		
 }
..............................................................................................................................
void gp22_wr_config_reg (uint8_t opcode_address,uint32_t config_reg_data)
{
 uint8_t Data_Byte_Lo = config_reg_data;
 uint8_t Data_Byte_Mid1 = config_reg_data>>8;
 uint8_t Data_Byte_Mid2 = config_reg_data>>16;
 uint8_t Data_Byte_Hi = config_reg_data>>24;
 
 //uint8_t common_delay = 10; // important delay (16) at SPI freq.=750kHz
 
 HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2,GPIO_PIN_RESET);
 
			 HAL_SPI_Transmit(&hspi3,&opcode_address,1,1);
		HAL_Delay(1);	
			 HAL_SPI_Transmit(&hspi3,&Data_Byte_Hi,1,1);
 HAL_Delay(1);
					HAL_SPI_Transmit(&hspi3,&Data_Byte_Mid2,1,1);
 HAL_Delay(1);
						HAL_SPI_Transmit(&hspi3,&Data_Byte_Mid1,1,1);
 HAL_Delay(1);
 // DATA LOW
					HAL_SPI_Transmit(&hspi3,&Data_Byte_Lo,1,1);	
 //Simple_delay_750ns((void*)common_delay);
		HAL_Delay(1);
 // Reset to device SPIx
 HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2, GPIO_PIN_SET);
}
............................................................................................................................
void gp22_send_1byte (uint8_t gp22_opcode_byte)
{
 // Deactivating Reset SPIx
 
 HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2,GPIO_PIN_RESET);
	 
		//while(__HAL_SPI_GET_FLAG(&hspi3,SPI_FLAG_TXE)==0){}
			 HAL_SPI_Transmit(&hspi3,&gp22_opcode_byte,1,1);
 //Simple_delay_750ns((void*)10);
			HAL_Delay(1);
	 //DWT_Delay_us (8);
			
 // OPCODE TO Device 
 // important delay (16) at SPI freq.=750kHz
 HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);
 // Reset to device SPIx
}

[aasil]

I'm expecting to read 0x12 but i always get 0xFF,I write to register 1 the value 0x12345678 And when i do the test by sending the opcode 0xB5, i should receive the highest 8 bits from that value (0x12).and i any thing write in reg1 i always recivce 0xff,i once replace my tdc_gp22 with a new one, but dont corrected,Where is my mistake? im very confused and tired,plese help me

[Tesla DeLorean]

Review the signal with a scope or logic analyzer. Understand if you're battling an issue on the STM32 or GP22

I suspect you need a delay after raising the chip select. I would use the TransmitReceive form to pull back data. Data sheet doesn't indicate the need for waits between single bytes.

[S.Ma]

Use an oscilloscope to look at NSS, MISO, MOSI and SCK and compare with datasheets.