Hi. I am afraid I am a bit lost 
I am trying to send and receive serial data using ESPHome.
Use case: I have a hot water cylinder temperature monitor with a serial data port. If I send a “R”, it returns a comma deiminated string containing the data I require.
Essentially, I would like to end up with an automation which runs every minute sending “R” to a ESP8266, and displaying the text response. I think I want to implement this: Custom UART Text Sensor — ESPHome
Is ESPHome a reasonable way to do this? This is my ESP yaml:
esphome:
name: hwc-monitor
includes:
- uart_read_line_sensor.h
esp8266:
board: d1_mini
# Enable logging
logger:
level: VERBOSE #makes uart stream available in esphome logstream
baud_rate: 0 #disable logging over uart
# Enable Home Assistant API
api:
encryption:
key: "OSvqW/yDWlIwdFtaHHFBimuXhic5jmF6lTQO5new+q4="
ota:
password: "48715da5f021aad02d4f4ce78f9e1c86"
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Hwc-Monitor Fallback Hotspot"
password: "ADekUGzzM6Kf"
captive_portal:
uart:
id: uart_bus
tx_pin: GPIO1
rx_pin: GPIO3
baud_rate: 57600
text_sensor:
- platform: custom
lambda: |-
auto my_custom_sensor = new UartReadLineSensor(id(uart_bus));
App.register_component(my_custom_sensor);
return {my_custom_sensor};
text_sensors:
id: "uart_readline"
switch:
- platform: uart
name: "Send_R"
data: 'R'
And this the uart_read_line_sensor.h
#include "esphome.h"
class UartReadLineSensor : public Component, public UARTDevice, public TextSensor {
public:
UartReadLineSensor(UARTComponent *parent) : UARTDevice(parent) {}
void setup() override {
// nothing to do here
}
int readline(int readch, char *buffer, int len)
{
static int pos = 0;
int rpos;
if (readch > 0) {
switch (readch) {
case '\n': // Ignore new-lines
break;
case '\r': // Return on CR
rpos = pos;
pos = 0; // Reset position index ready for next time
return rpos;
default:
if (pos < len-1) {
buffer[pos++] = readch;
buffer[pos] = 0;
}
}
}
// No end of line has been found, so return -1.
return -1;
}
void loop() override {
const int max_line_length = 80;
static char buffer[max_line_length];
while (available()) {
if(readline(read(), buffer, max_line_length) > 0) {
publish_state(buffer);
}
}
}
};
I have used a wemos D1 mini connected - it is programed as above, and installed as an ‘integration’ in Home Assistant.
Problems:
What changes do I need to make to the esp yamil (or .h file) to let me create the automation to send a “R” every 60 seconds, and display the response?
Currently I dont see any sensor, etc associated with this device that I can add to the dashboard…
Thank you for any help!
How do I get this log data (initially un-parsed) to be displayed on the HA dashboard? And I presume I will then be able to use the data to drive an automation (once it is parsed)?
