TIDA-060024: Problem in getting proper configurations

Hello Chetan, 

Our ultrasonic expert will get back to you on this. Please note that Monday September the 2nd is holiday. 

Hi Chetan,

Can you check the following?:

1. The MA40H1SR settings are intended for a half-bridge direct-drive use-case. The TIDA-060024 module is a transformer-driven solution. If you are to use the MA40H1SR settings, you will likely need to increase the preset 1 and 2 driver current limits to a value greater than the minimum of 50mA used in the direct drive case. 300mA is a typical value for transformer-driven mode.
2. What values are you seeing from the ultrasonic measurement result command? If you are seeing a time of flight value of 0xFFFF, this indicates no object has been detected. Since you do not have the full-scale EVM/GUI platform, you can use the echo data dump command to read back the 128 byte ultrasonic envelope to visually see how strong of an echo you are receiving. To pull the echo data dump, DATADUMP_EN has to be set to a value of '1' before you issue the burst-and/or-listen command.
3. Ensure your threshold values were written to the PGA460 properly. The THR_CRC_ERR should be a value of '0' if the threshold were updated successfully. If the thresholds are not written to once after start-up, then the device will not issue a burst-and/or-listen command.

Hi Akeem,

Thanks for response, i tried what you suggested results are as below.

>>I changed preset 1 and 2 current limits to 300mA  and result of ultrasonic measurement(0x05) am getting 0xFFFF continuously , there is a change on object detection as values changes to some random values from 0xFFFF, but the values received are not giving accurate distance.

>> I also checked with echo data dump, a continuous 0xFF's will change on object detection.

>>I also checked the THR_CRC_ERR value after configurations, value am getting is '0' so no errors with respect to threshold values update.

I have attached screenshot of ultrasonic measurement results value, please let me know what else i can try to get proper values. 

Hi Chetan,

You occasionally see a value at approximately 0x15CD, which is about 95cm in distance, so the threshold detection is working, but the echo data dump output could help confirm if the 95cm object is real or a false positive from the short to long digital gain adjustment.

Here is an alternative UART test sequence to determine if your PGA460 circuit is operational:
(Note, these examples assume your device is using the factory settings at UART_ADDR=0, you are using a transformer driven transducer, and using UART to communicate.)

1. Power-on device
2. Master transmit a threshold bulk write command (CMD16): 0x{55 10 88 88 88 88 88 88 84 21 08 42 10 80 80 80 80 00 88 88 88 88 88 88 84 21 08 42 10 80 80 80 80 00 85}
3. Master transmit a Preset 1 burst and listen command for 1 object (CMD 1): 0x{55 00 01 FE}
4. Master waits the equivalent of Preset 1's record length time of 8.192ms (factory default time)
5. Master requests slave to return the ultrasonic measurement results (CMD5): 0x{55 05}

If you want to read the echo data dump profile instead of the ultrasonic measurement results, perform the following instead:

1. Power-on device
2. Master transmit a threshold bulk write command (CMD16): 0x{10 52 98 5B 00 A1 D0 90 87 4D 1C C3 FE 89 24 5A D7 6D AD B9 D1 95 D5 5D 7C 57 31 13 A7 D6 51 42 56 23}
3. Master transmit a register write command (CMD10) to EE_CNTRL to set DATADUMP_EN=1: 0x{55 0A 40 80 35}
4. Master transmit a Preset 1 burst and listen command for 1 object (CMD 1): 0x{55 00 01 FE}
5. Master waits the equivalent of Preset 1's record length time of 8.192ms (factory default time)
6. Master requests slave to return the 128 bytes of echo data dump results (CMD5): 0x{55 07}

Hi Akeem,

Thanks for your response and support on this.

I have solved the issue , sensor is detecting objects after 40cm range, initially i have made a setup of square box of 40x40cm and hence i was not able to get any object detection.

Now i am able to detect the object after 40cm.

Actually our application needs very short range detection like 2cm - 100cm with "mm" accuracy.

Could you suggest me if any such ultrasonic sensor module available with TI.

Thanks and Regards,

Chetan Hiremath

Hi Akeem,

Thanks for the support given, i will look in to the alternate module options you have given.

Thanks and Regards,
Chetan Hiremath