Rather than re-invent the wheel, I’m including a link to a Smart Home Junkie YouTube video which does a good job of explaining how to add a card reader to Home Assistant..
Ok, so above, Smart Home Junkie has taken someone else’s work, made modifications and created a video on a DIY NFC reader… Which brings me to an important point: How come he has an NFC tag sticking out of his mouth? I didn’t get a free tag with my NFC reader.
So, basically I bought a USB-C Wemos D1 card from AliExpress (seveal in fact as they are great for WLED) – so no messing about with boot buttons when programming the board with ESP-HOME (in my case on my dedicated Home Assistant mini-PC). I also bought the red card reader board from AliExpress and I’m sure I got cheated out of that NFC tag.
So what started this all off? I have a SwitchBot NFC card which came with my Switchbot lock which I’ve reviewed elsewhere. As someone who knows absolutely zilch about NFC cards, I thought I’d give that a shot. Then I realised, of course, that if I wanted to try a NFC card, I could use any of my debit cards or anything like that. But then I read that you have to have a writable NFC card for use with a phone and the Home Assistant (companion app) tag reader, which I assumed the SwitchBot One was. Unfortunately, it isn’t. So, having got this little card reader running, I thought, “Right, I’ll use my phone instead of using the board. I’ll just simply have Home Assistant companion app pick up the card and do something with it.”
But no, you can’t do that. The Home Assistant Companion app assumes you have a writable card that has some kind of Home Assistant tag code in it (See the Home Assistant site). So that’s one idea up the Swanny, but here’s what I’ve made up to now, which seems to work quite well.
The reason I’m not making a big deal of this is now that I understand more about NFC cards, there are some neat writeable waterproof cards on AliExpress for next to nothing and it occurs to me that I might be better off getting a writeable card so that my phone can scan the card and pass that back to the Home Assistant Companion app for, for example, opening a gate as I get home, opening the front door and so on using a small round tag at each point.
I could of course simply open up the Home Assistant App and start pressing buttons but it seems that this might be easier. Both my wife’s phone and mine would respond to the tag(s).
So the card reader is explained in the Smart Home Junkie video above for anyone wanting to give it a shot.. (simply a matter of fastening the Wemos and tag redr cards together and adding a buzzer and WS2812 LED… and below I’m including the exact code I put into ESP-HOME – I added the web server so I can watch the output while testing. I also thought it might be nice to have a temperature sensor in there but as you see I’ve commented out the code for the latter. I had the lot working last night but when I came to it this morning – no tag reading so I’m wondering if maybe that’s pushing the little ESP8266 TOO far.
esphome:
name: tag-reader
friendly_name: tag-reader
esp8266:
board: d1_mini
# Enable logging
logger:
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Tag-Reader Fallback Hotspot"
password: "PNnTBtvLc5TG"
captive_portal:
web_server:
port: 80
#sensor:
# - platform: bme280_i2c
# temperature:
# name: "BME280 Temperature"
# accuracy_decimals: 0
# pressure:
# name: "BME280 Pressure"
# accuracy_decimals: 0
# humidity:
# name: "BME280 Humidity"
# accuracy_decimals: 0
improv_serial:
substitutions:
name: tagreader
friendly_name: TagReader
# Automatically add the mac address to the name
# so you can use a single firmware for all devices
name_add_mac_suffix: true
# This will allow for (future) project identification,
# configuration and updates.
project:
name: adonno.tag_reader
version: "1.4"
# If buzzer is enabled, notify on api connection success
on_boot:
priority: -10
then:
- wait_until:
api.connected:
- logger.log: API is connected!
- rtttl.play: "success:d=24,o=5,b=100:c,g,b"
- light.turn_on:
id: activity_led
brightness: 100%
red: 0%
green: 0%
blue: 100%
flash_length: 500ms
- switch.turn_on: buzzer_enabled
- switch.turn_on: led_enabled
# Define switches to control LED and buzzer from HA
switch:
- platform: template
name: "${friendly_name} Buzzer Enabled"
id: buzzer_enabled
icon: mdi:volume-high
optimistic: true
restore_mode: RESTORE_DEFAULT_ON
entity_category: config
- platform: template
name: "${friendly_name} LED enabled"
id: led_enabled
icon: mdi:alarm-light-outline
optimistic: true
restore_mode: RESTORE_DEFAULT_ON
entity_category: config
# Define buttons for writing tags via HA
button:
- platform: template
name: Write Tag Random
id: write_tag_random
# Optional variables:
icon: "mdi:pencil-box"
on_press:
then:
- light.turn_on:
id: activity_led
brightness: 100%
red: 100%
green: 0%
blue: 100%
- lambda: |-
static const char alphanum[] = "0123456789abcdef";
std::string uri = "https://www.home-assistant.io/tag/";
for (int i = 0; i < 8; i++)
uri += alphanum[random_uint32() % (sizeof(alphanum) - 1)];
uri += "-";
for (int j = 0; j < 3; j++) {
for (int i = 0; i < 4; i++)
uri += alphanum[random_uint32() % (sizeof(alphanum) - 1)];
uri += "-";
}
for (int i = 0; i < 12; i++)
uri += alphanum[random_uint32() % (sizeof(alphanum) - 1)];
auto message = new nfc::NdefMessage();
message->add_uri_record(uri);
ESP_LOGD("tagreader", "Writing payload: %s", uri.c_str());
id(pn532_board).write_mode(message);
- rtttl.play: "write:d=24,o=5,b=100:b"
- wait_until:
not:
pn532.is_writing:
- light.turn_off:
id: activity_led
- rtttl.play: "write:d=24,o=5,b=100:b,b"
- platform: template
name: Clean Tag
id: clean_tag
icon: "mdi:nfc-variant-off"
on_press:
then:
- light.turn_on:
id: activity_led
brightness: 100%
red: 100%
green: 64.7%
blue: 0%
- lambda: 'id(pn532_board).clean_mode();'
- rtttl.play: "write:d=24,o=5,b=100:b"
- wait_until:
not:
pn532.is_writing:
- light.turn_off:
id: activity_led
- rtttl.play: "write:d=24,o=5,b=100:b,b"
- platform: template
name: Cancel writing
id: cancel_writing
icon: "mdi:pencil-off"
on_press:
then:
- lambda: 'id(pn532_board).read_mode();'
- light.turn_off:
id: activity_led
- rtttl.play: "write:d=24,o=5,b=100:b,b"
- platform: restart
name: "${friendly_name} Restart"
entity_category: config
# Enable Home Assistant API
api:
services:
- service: rfidreader_tag_ok
then:
- rtttl.play: "beep:d=16,o=5,b=100:b"
- service: rfidreader_tag_ko
then:
- rtttl.play: "beep:d=8,o=5,b=100:b"
- service: play_rtttl
variables:
song_str: string
then:
- rtttl.play: !lambda 'return song_str;'
- service: write_tag_id
variables:
tag_id: string
then:
- light.turn_on:
id: activity_led
brightness: 100%
red: 100%
green: 0%
blue: 0%
- lambda: |-
auto message = new nfc::NdefMessage();
std::string uri = "https://www.home-assistant.io/tag/";
uri += tag_id;
message->add_uri_record(uri);
id(pn532_board).write_mode(message);
- rtttl.play: "write:d=24,o=5,b=100:b"
- wait_until:
not:
pn532.is_writing:
- light.turn_off:
id: activity_led
- rtttl.play: "write:d=24,o=5,b=100:b,b"
- service: write_music_tag
variables:
music_url: string
music_info: string
then:
- light.turn_on:
id: activity_led
brightness: 100%
red: 100%
green: 0%
blue: 0%
- lambda: |-
auto message = new nfc::NdefMessage();
std::string uri = "";
std::string text = "";
uri += music_url;
text += music_info;
if ( music_url != "" ) {
message->add_uri_record(uri);
}
if ( music_info != "" ) {
message->add_text_record(text);
}
id(pn532_board).write_mode(message);
- rtttl.play: "write:d=24,o=5,b=100:b"
- wait_until:
not:
pn532.is_writing:
- light.turn_off:
id: activity_led
- rtttl.play: "write:d=24,o=5,b=100:b,b"
# Enable OTA upgrade
ota:
platform: esphome
i2c:
scan: False
frequency: 400kHz
globals:
- id: source
type: std::string
- id: url
type: std::string
- id: info
type: std::string
pn532_i2c:
id: pn532_board
on_tag:
then:
- if:
condition:
switch.is_on: led_enabled
then:
- light.turn_on:
id: activity_led
brightness: 100%
red: 0%
green: 100%
blue: 0%
flash_length: 500ms
- delay: 0.15s #to fix slow component
- lambda: |-
id(source)="";
id(url)="";
id(info)="";
if (tag.has_ndef_message()) {
auto message = tag.get_ndef_message();
auto records = message->get_records();
for (auto &record : records) {
std::string payload = record->get_payload();
std::string type = record->get_type();
size_t hass = payload.find("https://www.home-assistant.io/tag/");
size_t applemusic = payload.find("https://music.apple.com");
size_t spotify = payload.find("https://open.spotify.com");
size_t sonos = payload.find("sonos-2://");
if (type == "U" and hass != std::string::npos ) {
ESP_LOGD("tagreader", "Found Home Assistant tag NDEF");
id(source)="hass";
id(url)=payload;
id(info)=payload.substr(hass + 34);
}
else if (type == "U" and applemusic != std::string::npos ) {
ESP_LOGD("tagreader", "Found Apple Music tag NDEF");
id(source)="amusic";
id(url)=payload;
}
else if (type == "U" and spotify != std::string::npos ) {
ESP_LOGD("tagreader", "Found Spotify tag NDEF");
id(source)="spotify";
id(url)=payload;
}
else if (type == "U" and sonos != std::string::npos ) {
ESP_LOGD("tagreader", "Found Sonos app tag NDEF");
id(source)="sonos";
id(url)=payload;
}
else if (type == "T" ) {
ESP_LOGD("tagreader", "Found music info tag NDEF");
id(info)=payload;
}
else if ( id(source)=="" ) {
id(source)="uid";
}
}
}
else {
id(source)="uid";
}
- if:
condition:
lambda: 'return ( id(source)=="uid" );'
then:
- homeassistant.tag_scanned: !lambda |-
ESP_LOGD("tagreader", "No HA NDEF, using UID");
return x;
else:
- if:
condition:
lambda: 'return ( id(source)=="hass" );'
then:
- homeassistant.tag_scanned: !lambda 'return id(info);'
else:
- homeassistant.event:
event: esphome.music_tag
data:
reader: !lambda |-
return App.get_name().c_str();
source: !lambda |-
return id(source);
url: !lambda |-
return id(url);
info: !lambda |-
return id(info);
- if:
condition:
switch.is_on: buzzer_enabled
then:
- rtttl.play: "success:d=24,o=5,b=100:c,g,b"
on_tag_removed:
then:
- homeassistant.event:
event: esphome.tag_removed
# Define the buzzer output
output:
- platform: esp8266_pwm
pin: D7
id: buzzer
binary_sensor:
- platform: status
name: "${friendly_name} Status"
entity_category: diagnostic
text_sensor:
- platform: version
hide_timestamp: true
name: "${friendly_name} ESPHome Version"
entity_category: diagnostic
- platform: wifi_info
ip_address:
name: "${friendly_name} IP Address"
icon: mdi:wifi
entity_category: diagnostic
ssid:
name: "${friendly_name} Connected SSID"
icon: mdi:wifi-strength-2
entity_category: diagnostic
# Define buzzer as output for RTTTL
rtttl:
output: buzzer
# Configure LED
light:
- platform: neopixelbus
variant: WS2812
pin: D8
num_leds: 1
flash_transition_length: 500ms
type: GRB
id: activity_led
name: "${friendly_name} LED"
restore_mode: ALWAYS_OFF