awbnet
commented
2 years ago @ProBackup-nl That is a known isssue with SDS011 and NAM/NAMF. We've tried tons of combinations and… no luck in fixing this bug. We think that this problem is caused by bug in SDS firmware.
Current workaround is to power cycle your sensor. Software reboot won't help. :( There is a special "watchdog" or hardware SDS restarter daughterboard available for NAM sensor: https://nettigo.pl/products/sprzetowy-restarter-sds011-do-nam-0-3
You plug this module into NAM EXT port then connect SDS by cable to this module and enable restarter in NAMF software.
A configuration change + soft restart didn't improve. After 145 seconds still no particulate matter was read:
[2022-02-16 19:33:08]
{"esp8266id": "1XXXXXX4", "software_version": "NAMF-2020-43", "sensordatavalues":[{"value_type":"SHT3X_temperature","value":"13.02"},{"value_type":"SHT3X_humidity","value":"89.40"},{"value_type":"HECA_temperature","value":"17.88"},{"value_type":"HECA_humidity","value":"64.73"},{"value_type":"HECA_Tdc","value":"0.00"},{"value_type":"HECA_RHdc","value":"100.00"},{"value_type":"HECA_dc","value":"100.00"},{"value_type":"BMP_pressure","value":"99386.40"},{"value_type":"BMP_temperature","value":"12.30"},{"value_type":"samples","value":"112549"},{"value_type":"min_micro","value":"1222"},{"value_type":"max_micro","value":"90517"},{"value_type":"signal","value":"-73"}]}A cold boot (power cycling) did fix the SDS011 readings:
[2022-02-16 19:38:51]
{"esp8266id": "1XXXXXX4", "software_version": "NAMF-2020-43", "sensordatavalues":[{"value_type":"SDS_P1","value":"1.40"},{"value_type":"SDS_P2","value":"0.80"},{"value_type":"SHT3X_temperature","value":"13.05"},{"value_type":"SHT3X_humidity","value":"89.51"},{"value_type":"HECA_temperature","value":"18.35"},{"value_type":"HECA_humidity","value":"63.53"},{"value_type":"HECA_Tdc","value":"0.00"},{"value_type":"HECA_RHdc","value":"100.00"},{"value_type":"HECA_dc","value":"100.00"},{"value_type":"BMP_pressure","value":"99381.00"},{"value_type":"BMP_temperature","value":"12.30"},{"value_type":"samples","value":"104553"},{"value_type":"min_micro","value":"1305"},{"value_type":"max_micro","value":"546981"},{"value_type":"signal","value":"-72"}]}