CCS/PGA460: Batch configuration parameters behave differently

user5886154,

If you know you have a unreliable/blind zone of sub-25cm, I recommend that you saturate your initial threshold level to prevent false-positives in this measurement range. See PGA460 FAQ#5.2 ( ) for details of saturating the threshold for a masking effect of ignoring echo data. Alternatively, you can set the number of objects to detect in your burst/listen command to be greater than one (up to eight) to check for false-positives in the blind zone, but also detect a real object at 255cm.

For you checksum function, please refer to the following checksum function example implementation from the "PGA460 Energia Library and Code Example" software ( ):

/*------------------------------------------------- calcChecksum -----
 |  Function calcChecksum
 |
 |  Purpose:  Calculates the UART checksum value based on the selected command and the user EERPOM values associated with the command
 |		This function is not applicable to TCI mode. 
 |
 |  Parameters:
 |		cmd (IN) -- the UART command for which the checksum should be calculated for
 |
 |  Returns: byte representation of calculated checksum value
 *-------------------------------------------------------------------*/
byte pga460::calcChecksum(byte cmd)
{
	int checksumLoops = 0;
	
	cmd = cmd & 0x001F; // zero-mask command address of cmd to select correct switch-case statement
	
	switch(cmd)
	{
		case 0 : //P1BL
		case 1 : //P2BL
		case 2 : //P1LO
		case 3 : //P2LO
		case 17 : //BC_P1BL
		case 18 : //BC_P2BL
		case 19 : //BC_P1LO
		case 20 : //BC_P2LO
			ChecksumInput[0] = cmd;
			ChecksumInput[1] = numObj;
			checksumLoops = 2;
		break;
		case 4 : //TNLM
		case 21 : //TNLM
			ChecksumInput[0] = cmd;
			ChecksumInput[1] = tempOrNoise;
			checksumLoops = 2;
		break;
		case 5 : //UMR
		case 6 : //TNLR
		case 7 : //TEDD
		case 8 : //SD
		case 11 : //EEBR
		case 13 : //TVGBR
		case 15 : //THRBR
			ChecksumInput[0] = cmd;
			checksumLoops = 1;
		break;
		case 9 : //RR
			ChecksumInput[0] = cmd;
			ChecksumInput[1] = regAddr;
			checksumLoops = 2;
		break;
		case 10 : //RW
		case 22 : //BC_RW
			ChecksumInput[0] = cmd;
			ChecksumInput[1] = regAddr;
			ChecksumInput[2] = regData;
			checksumLoops = 3;
		break;
		case 14 : //TVGBW
		case 24 : //BC_TVGBW
			ChecksumInput[0] = cmd;
			ChecksumInput[1] = TVGAIN0;
			ChecksumInput[2] = TVGAIN1;
			ChecksumInput[3] = TVGAIN2;
			ChecksumInput[4] = TVGAIN3;
			ChecksumInput[5] = TVGAIN4;
			ChecksumInput[6] = TVGAIN5;
			ChecksumInput[7] = TVGAIN6;
			checksumLoops = 8;
		break;
		case 16 : //THRBW
		case 25 : //BC_THRBW
			ChecksumInput[0] = cmd;
			ChecksumInput[1] = P1_THR_0;
			ChecksumInput[2] = P1_THR_1;
			ChecksumInput[3] = P1_THR_2;
			ChecksumInput[4] = P1_THR_3;
			ChecksumInput[5] = P1_THR_4;
			ChecksumInput[6] = P1_THR_5;
			ChecksumInput[7] = P1_THR_6;
			ChecksumInput[8] = P1_THR_7;
			ChecksumInput[9] = P1_THR_8;
			ChecksumInput[10] = P1_THR_9;
			ChecksumInput[11] = P1_THR_10;
			ChecksumInput[12] = P1_THR_11;
			ChecksumInput[13] = P1_THR_12;
			ChecksumInput[14] = P1_THR_13;
			ChecksumInput[15] = P1_THR_14;
			ChecksumInput[16] = P1_THR_15;
			ChecksumInput[17] = P2_THR_0;
			ChecksumInput[18] = P2_THR_1;
			ChecksumInput[19] = P2_THR_2;
			ChecksumInput[20] = P2_THR_3;
			ChecksumInput[21] = P2_THR_4;
			ChecksumInput[22] = P2_THR_5;
			ChecksumInput[23] = P2_THR_6;
			ChecksumInput[24] = P2_THR_7;
			ChecksumInput[25] = P2_THR_8;
			ChecksumInput[26] = P2_THR_9;
			ChecksumInput[27] = P2_THR_10;
			ChecksumInput[28] = P2_THR_11;
			ChecksumInput[29] = P2_THR_12;
			ChecksumInput[30] = P2_THR_13;
			ChecksumInput[31] = P2_THR_14;
			ChecksumInput[32] = P2_THR_15;
			checksumLoops = 33;
		break;
		case 12 : //EEBW
		case 23 : //BC_EEBW
			ChecksumInput[0] = cmd;
			ChecksumInput[1] = USER_DATA1;
			ChecksumInput[2] = USER_DATA2;
			ChecksumInput[3] = USER_DATA3;
			ChecksumInput[4] = USER_DATA4;
			ChecksumInput[5] = USER_DATA5;
			ChecksumInput[6] = USER_DATA6;
			ChecksumInput[7] = USER_DATA7;
			ChecksumInput[8] = USER_DATA8;
			ChecksumInput[9] = USER_DATA9;
			ChecksumInput[10] = USER_DATA10;
			ChecksumInput[11] = USER_DATA11;
			ChecksumInput[12] = USER_DATA12;
			ChecksumInput[13] = USER_DATA13;
			ChecksumInput[14] = USER_DATA14;
			ChecksumInput[15] = USER_DATA15;
			ChecksumInput[16] = USER_DATA16;
			ChecksumInput[17] = USER_DATA17;
			ChecksumInput[18] = USER_DATA18;
			ChecksumInput[19] = USER_DATA19;
			ChecksumInput[20] = USER_DATA20;
			ChecksumInput[21] = TVGAIN0;
			ChecksumInput[22] = TVGAIN1;
			ChecksumInput[23] = TVGAIN2;
			ChecksumInput[24] = TVGAIN3;
			ChecksumInput[25] = TVGAIN4;
			ChecksumInput[26] = TVGAIN5;
			ChecksumInput[27] = TVGAIN6;
			ChecksumInput[28] = INIT_GAIN;
			ChecksumInput[29] = FREQUENCY;
			ChecksumInput[30] = DEADTIME;
			ChecksumInput[31] = PULSE_P1;
			ChecksumInput[32] = PULSE_P2;
			ChecksumInput[33] = CURR_LIM_P1;
			ChecksumInput[34] = CURR_LIM_P2;
			ChecksumInput[35] = REC_LENGTH;
			ChecksumInput[36] = FREQ_DIAG;
			ChecksumInput[37] = SAT_FDIAG_TH;
			ChecksumInput[38] = FVOLT_DEC;
			ChecksumInput[39] = DECPL_TEMP;
			ChecksumInput[40] = DSP_SCALE;
			ChecksumInput[41] = TEMP_TRIM;
			ChecksumInput[42] = P1_GAIN_CTRL;
			ChecksumInput[43] = P2_GAIN_CTRL;
			checksumLoops = 44;
		break;
		default: break;
	}

	if (ChecksumInput[0]<17) //only re-append command address for non-broadcast commands.
	{
		ChecksumInput[0] = ChecksumInput[0] + (uartAddr << 5);
	}
	
	uint16_t carry = 0;

	for (int i = 0; i < checksumLoops; i++)
	{
		if ((ChecksumInput[i] + carry) < carry)
		{
			carry = carry + ChecksumInput[i] + 1;
		}
		else
		{
			carry = carry + ChecksumInput[i];
		}

		if (carry > 0xFF)
		{
		  carry = carry - 255;
		}
	}
	
	carry = (~carry & 0x00FF);
	return carry;
}