Wheeltick and dr feature in lc29h

IoT Modules GNSS Module
1

In LC29H GNSS module I want a detail description of WHEELTICK and DR feature. Do we have to calculate GPS using DR when signal is lost based on the speed and initial location or can it automatically calculates GPS when we input Speed pulses externally through a microcontroller? If yes, how we can make it through PAIR messages or PQTM messages or directly connect speed pulses to WHEELTICK pin?

2

Hi Vijayamounika Laxven,

I will send you DR application note via message. The speed injection methods are shown below.

Method 1: The wheel-tick pulse is injected through the module pins, and the firmware counts by itself. The distance increment corresponding to one pulse is required to be no more than 5 cm.

Method 2: Inject the wheel speed through the serial port. The injection wheeltick is the cumulative value, the injection frequency is not less than 10Hz, and the distance increment corresponding to one pulse is required to be no more than 5 cm.

Remarks: When the wheel speed accuracy requirement of not more than 5 cm cannot be met, the accuracy of the appropriate relaxation (limited to the order of centimeters) will affect the overall positioning performance. Due to the difference in the final hardware form of the product, the impact on the accuracy needs to be evaluated through the actual measurement of the whole machine.

Finally, please pay attention to your application is a 4-wheels vehicle or 2-wheels vehicle.

Best regards.

3

Thanks for your response.
My application is neither 4 wheel vehicle or 2 wheel vehicle but we can give cumulative speed input. And my actual doubt, is it enough to input speed or do we need do give commands to use this in software development

4

Can you tell me how wheel ticks are calculated, like 1 wheel tick= how many pulses and what is width and frequency of the pulse signal.

5

Hi Vijayamounika,

If you connect WHEELTICK pin with your speed sensor, you don’t need to send any command or configuration to the module. The module will detect the pulse automatically.

There is no requirement for wheeltick pulse width. The distance increment corresponding to one pulse is required to be no more than 5 cm.

Best regards