【2024 DigiKey Innovation Competition】Ultrasonic Sensing Matrix: Driving and Measurement Circuits

lcdi

【2024 DigiKey Innovation Competition】Ultrasonic Sensing Matrix: Driving and Measurement Circuits [Copy link]

 

Phase 1:

A major challenge of this project is to complete the ultrasonic ranging function with the highest efficiency, high performance and low cost.

The ultrasonic sensor uses a waterproof integrated transceiver sensor. Because it is a capacitive load, the current requirement is not high, but the driving voltage directly affects the ultrasonic intensity. The dedicated drive can even reach more than 100V.

However, considering efficiency and cost, the design idea of this project is to have a low transmission intensity and mainly test algorithms to improve receiving performance.

The design of the launch part was simplified from the beginning, and three driving schemes were conceived.

1. Inspired by the boost circuit, the boost effect of the inductor is used to generate pulses to drive the ultrasonic sensor.

2. Use a micro transformer used for flashlights to increase the voltage by about 10 to 15 times.

3. Use the motor driver chip mx6208 to introduce a higher separate driving voltage.

Test in parallel and select the best one.

The receiving part mainly uses the gs8721 op amp to build an AC amplifier, which is then input into the esp32c6, and the ADC samples are stored in RAM.

The focus of later tests is on algorithms~

(However, the main control I chose this time was not suitable. At the beginning, I only considered that there was sufficient RAM for cache and processing. Unexpectedly, the ADC performance of esp32c6 was poor, the speed was only 100k, and the accuracy was also relatively poor, which is estimated to affect the effect.)

Jacktang

It seems that the ADC performance of esp32c6 is really poor, the speed is only 100k, indeed

lcdi

Jacktang posted on 2024-9-30 07:31 It seems that the ADC performance of esp32c6 is really poor, the speed is only 100k, indeed

This accuracy index is also very poor. The INL of general MCU is within 4LSB. The ESP32C6 is at the bottom, not even as good as 10-bit AD.