/esp8266_ping

Ultrasonic sensor driver for the esp8266

Primary LanguageCGNU General Public License v3.0GPL-3.0

esp8266_ping

A HC-SR04, HY-SRF05 driver and example for the esp8266.

#include "ping/ping.h"
....
static Ping_Data pingA;
....
// setup
int triggerPin = 0;
int echoPin = 2;
ping_init(&pingA, triggerPin, echoPin, PING_MM); // set the trigger and echo pin to the same number for one-pin mode

....
// loop:
float distance = 0;
float maxDistance = 500;
if (ping_pingDistance(&pingA, maxDistance, &distance) ) {
  os_printf("Response ~ %d mm \n", (int)distance);
} else {
  os_printf("Failed to get any response.\n");
}

Makefile:

MODULES         = driver/stdout driver/easygpio driver/ping user

##Circuit The HC-SR04 is a 5V device, so you will (at the very least) need a voltage divider on the echo pin. Or even better: a logic level shifter

single pin mode

If you want to run this in 'single pin mode' behind a logic level shifter you can connect the echo pin on the 3V3 side to the trigger GPIO via a 5KΩ resistor. That works for me at least.

esp8266 via level shifter 3V3 level shifter 5V HC-SR04
GPIOX - port1 3V3 port1 5V trigger
GPIOX 5kΩ port2 3V3 port2 5V echo

It would be nice if some EE could verify this hookup.

Wiring echo & trigger together on the 5V side does not work.

other sensors

The arduino library newping supports a whole range of ultrasonic sensors: SR04, SRF05, SRF06, DYP-ME007 & Parallax PING™. This without making any special hardware considerations in the code. So this library might work with those sensors as well.

TODO

  • inches
  • single pin mode
  • multiple sensors
  • sdk v0.9.5 compability
  • check compability SRF05 SRF05 works w/o any modifications
  • check compability SRF06
  • check compability DYP-ME007
  • check compability Parallax PING™

License

GPL V3

The makefile is copied from esp_mqtt.

###Building and installing:

First you need to install the sdk and the easy way of doing that is to use esp_open_sdk.

You can put that anywhere you like (/opt/local/esp-open-sdk, /esptools etc etc)

Then you could create a small setenv.sh file, containing the location of your newly compiled sdk and other platform specific info;

export SDK_BASE=/opt/local/esp-open-sdk/sdk
export PATH=${SDK_BASE}/../xtensa-lx106-elf/bin:${PATH}
export ESPPORT=/dev/ttyO0

(or setup your IDE to do the same)

To make a clean build, flash and connect to the esp console you just do this in a shell:

source setenv.sh # This is only needed once per session
make clean && make test

You won't be needing esptool, the makefile only uses esptool.py (provided by esp_open_sdk)

I have tested this with sdk v0.9.4 and v0.9.5 (linux & mac)