StickV的串口通信与servo-hat应用

servo-hat是一款舵机模块，通过esp32的ledc可以直接输出PWM进行控制标称输出角度为145°±10°，实测可以达到170多度。由于ledc配置比较简单因此没有封装库，使用前简单配置一下参数。
[mw_shl_code=c,true]#define COUNT_LOW 1800
#define COUNT_HIGH 8000
#define TIMER_WIDTH 16
#include "esp32-hal-ledc.h"
#include <M5StickC.h>

void setup() {
// put your setup code here, to run once:
M5.begin();
ledcSetup(1, 50, TIMER_WIDTH);
ledcAttachPin(26, 1);           /
M5.Lcd.setCursor(20, 80, 2);
M5.Lcd.print("SERVO");

}

void loop() {
// put your main code here, to run repeatedly:
for(int i = COUNT_LOW; i < COUNT_HIGH; i = i+100){
ledcWrite(1, i);
delay(50);
}
}[/mw_shl_code]

有了以上的基础，接下来做一个虚拟指针。最终实现效果为根据Stickv识别的物体，由舵机指向该物体。StickV有GROVE输出，可自由配置IO控制舵机，但由于servo-hat需要配合StickC，因此将StickV的GROVE配置为UART与StickC进行通信，StickC根据接收信息控制舵机。


首先需要对StickV进行模型训练操作，具体方法参考V-TRAINING
https://docs.m5stack.com/#/en/related_documents/v-training


模型训练好以后修改boot.py，通过fpioa_manager配置UART,CONNEXT_A为RX,CONNEXT_B为TX


[mw_shl_code=python,true]import image
import lcd
import sensor
import sys
import time
import KPU as kpu
from fpioa_manager import fm
from machine import UART

fm.register(board_info.CONNEXT_A,fm.fpioa.UART1_RX)
fm.register(board_info.CONNEXT_B,fm.fpioa.UART1_TX)

uart_A = UART(UART.UART1, 115200)

lcd.init()
lcd.rotation(2)

try:
img = image.Image("/sd/startup.jpg")
lcd.display(img)
except:
lcd.draw_string(lcd.width()//2-100,lcd.height()//2-4, "Error: Cannot find start.jpg", lcd.WHITE, lcd.RED)


task = kpu.load("/sd/b7fbf3aad4caf26a_mbnet10_quant.kmodel")

labels=["M5Stack Fire","M5StickC","M5Stick"] #You can check the numbers here to real names.

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.set_windowing((224, 224))
sensor.run(1)

lcd.clear()


while(True):
img = sensor.snapshot()
fmap = kpu.forward(task, img)
plist=fmap[:]
pmax=max(plist)
max_index=plist.index(pmax)
a = lcd.display(img)
uart_A.write('clear')
uart_A.write('\r')
if pmax > 0.95:
lcd.draw_string(5, 60, "Accu:%.2f Type:%s"%(pmax, labels[max_index].strip()))  
uart_A.write(labels[max_index])
uart_A.write('\r')

a = kpu.deinit(task)
[/mw_shl_code]
本例训练了3个模型，分别为M5Stack Fire，M5StickC，M5Stick。识别到目标后串口输出目标对象。

接下来进行StickC端的代码编写，配置ledc，对串口字符进行处理，这里对串口数据转换为字符串进行对比，根据结果控制舵机旋转指定的位置

[mw_shl_code=c,true]#include "esp32-hal-ledc.h"
#include <M5StickC.h>

#define TIMER_WIDTH 16   //精度
#define CHANNEL 0        //通道
#define FREQUANCE 50  //频率
#define PIN 26     //舵机引脚


String comData = "";
String lastContent = "";
bool flag;
void setup() {
M5.begin();
// Serial2.begin(unsigned long baud, uint32_t config, int8_t rxPin, int8_t txPin, bool invert)
Serial2.begin(115200, SERIAL_8N1, 33, 32);      //串口2初始化操作
ledcSetup(CHANNEL, FREQUANCE, TIMER_WIDTH);
ledcAttachPin(PIN, CHANNEL);
}

void loop() {
if(Serial2.available()){
comData = "";
while(Serial2.available()){
char ch = Serial2.read();
if(ch != '\r'){
comData += ch;
}
}
if(comData == "clear"){
M5.Lcd.fillScreen(BLACK);
comData = "";
ledcWrite(CHANNEL, 8000);
return;  
}
if(lastContent != comData){
M5.Lcd.setCursor(0, 0);
M5.Lcd.print(comData);
}  
if(comData == "M5StickC"){
ledcWrite(CHANNEL, 5000);
}else if(comData == "M5Stack Fire"){
ledcWrite(CHANNEL, 6500);
}else if(comData == "M5Stick")
ledcWrite(CHANNEL, 8000);
}
} [/mw_shl_code]

视频效果如下：

了解一下