SDS011 sensor + TTGOV1.6 LoRa issue

[FabTangi]

Hello, Using this code with an SDS011 sensor and a TTGOV1.6, I have an issue. Lora handshake and SDS011 data are OK. 1 frame is sent, and the the sensor continue, but no more frames are sent. There is also an error just after sending the Lora frame :

_22:22:47.075 > [ 43665][I][sds011read.cpp:37] sds011_loop(): SDS011: pm25: 4.10, pm10: 14.20 22:23:14.917 > [ 71507][I][lorawan.cpp:224] lora_send(): 6 byte(s) sent to LORA 22:23:19.958 > FAILURE 22:23:19.958 > .pio/libdeps/usb/MCCI LoRaWAN LMIC library/src/lmic/radio.c:1065 22:23:47.076 > [103665][I][sds011read.cpp:37] sds011_loop(): SDS011: pm25: 3.90, pm10: 13.10 22:24:47.076 > [163665][I][sds011read.cpp:37] sds011loop(): SDS011: pm25: 4.00, pm10: 13.00

Any idea ?

[cyberman54]

This is Lora related problem, not an SDS011 specific issue. Make sure that the SPI interface to the Lora chip is working. The error in line 1065 of radio.c points to non working Lora chip, because the radio driver reports that it cannot activate RX mode.

[FabTangi]

Well, it is linked to SDS011, because if SDS011 is not powered, the paxcounter on TTGO V1.6 is working properly, without any Lora issue...

[cyberman54]

To which pins did you connect the SDS011?

[FabTangi]

Well I used pin 19 and 23 and added in hal file ttgov21new.h :

// SDS011 dust sensor settings

define HAS_SDS011 1 // use SDS011

// used pins on the ESP-side:

define SDS_TX 19 // connect to RX on the SDS011

define SDS_RX 23 // connect to TX on the SDS011

[cyberman54]

Pins 19+23 are used on TTGO v1.6 for SPI interface of Lora chip. Thus, you cannot use these pins for serial interface of SDS011.

Check your wiring.

[cyberman54]

Use IO12 and IO35.