Hi,
I am trying to build an NFC reader. I have the Grove NFC v1.1 PN532-based NFC reader
Grove - NFC - Seeed Studio
around a LIlygo T18 esp32 unit. The pinout is here
LilyGO/LILYGO-T-Energy (github.com)
It seems this reader only works over UART or I2C, so I am trying to use it over I2C. I have the following error:
[14:49:00][C][i2c.arduino:052]: I2C Bus:
[14:49:00][C][i2c.arduino:053]: SDA Pin: GPIO21
[14:49:00][C][i2c.arduino:054]: SCL Pin: GPIO22
[14:49:00][C][i2c.arduino:055]: Frequency: 50000 Hz
[14:49:00][C][i2c.arduino:058]: Recovery: bus successfully recovered
[14:49:00][I][i2c.arduino:068]: Results from i2c bus scan:
[14:49:00][I][i2c.arduino:070]: Found no i2c devices!
I don’t quite know what I am doing with hardware, so here is what I have done:
-
I have cut the NFC unit’s UART jumpers and soldered the I2C ones:
P1 – I2C
P2 – SCL
P3 – SDA -
I have connected the NFC unit to the following pins:
* SDA to Pin 21
* SCL to Pin 22
* VCC to Pin 3V3 (I have also tried 5V, but no difference)
* GND to one of the GND pins
This is how I have configured it in esphome (relevant part only – the wifi/ap etc all work and I see the sensors in HA):
i2c:
sda: 21
scl: 22
scan: true
id: bus_a
pn532_i2c:
update_interval: 1s
i2c_id: bus_a
on_tag:
then:
- text_sensor.template.publish:
id: rfid_tag
state: !lambda 'return x;'
text_sensor:
- platform: template
name: "${device_name_up} NFC Tag"
id: rfid_tag
Does anyone have any suggestions for what the problem may be?