Calibration.MDEK1001

Hi Evryone;

I have read several materiaals regarding calibration. However; I do not underestand the main point. Do the MDEK1001 need calibration and why we need it at all. Can anyone give me a simple example for more clarification?

Thank you so much.

Hi Sara,

The DWM1001 are calibrated in production, and the antenna delay value are actually stored in the OTP memory.

So you don’t need to do any further calibration.

Thank you,
Regards
Yves

Hi Sara,

The DWM1001 are calibrated in production, and the antenna delay value are actually stored in the OTP memory.

So you don’t need to do any further calibration.

Thank you,
Regards
Yves

I was asking myself the same question as Sara. I’ve got some DWM1001-DEV Boards which do not seem to have antenna delay calibrated. Whats more is that Unique Device ID doesn’t seem to be set in OTP either.

Maybe this is because I am using DEV boards?

Best regards,
Julian

Hi FranzKnut,

For the DWM1001 module the antenna delay is written in the OPT during manufacturing. So it should be set with the DWM1001-DEV board.

What makes you think it is not setup ?

Thanks
Yves

When I do not set the Antenna Delay manually TWR results do have an offset.
Also when calling

dwt_otpread(0x01c, &antdly, 1);

antdly is set to 0xffffffff.

Best regards, Julian

Hi Julian,

When writing/reading to/from the OTP, the DW1000 system clock is divided from the crystal oscillator and not the PLL. This clock is much slower, and consequently, it will take more time to proceed the instruction. As a consequence the SPI clock needs to be reduced to 2Mhz. This is done in the simple example on git, for the DW1000 configuration.

You will successfully read the OTP by setting the SPI clock to the slow speed. Otherwise the value reported by the opt read command will not be valid.

Thank you,
Best regards
Yves

Although it is possible to read out the factory calibrated antenna delay, applying it to the two-way ranging examples does not improve the range accuracy. As highlighted in my forum post the antenna delays are only applicable to a specific channel, preamble, PRF configuration and I have not been able to identify this yet.