It would appear the plugin is no longer working with the PurpleAir API.
[2019-11-9 07:56:42] ReferenceError: pmtoString is not defined
at PurpleAirAccessory.updateData (/usr/local/lib/node_modules/homebridge-purpleair/index.js:155:54)
at Request._callback (/usr/local/lib/node_modules/homebridge-purpleair/index.js:50:32)
at Request.self.callback (/usr/local/lib/node_modules/request/request.js:185:22)
at emitTwo (events.js:125:13)
at Request.emit (events.js:213:7)
at Request. (/usr/local/lib/node_modules/request/request.js:1161:10)
at emitOne (events.js:115:13)
at Request.emit (events.js:210:7)
at IncomingMessage. (/usr/local/lib/node_modules/request/request.js:1083:12)
at Object.onceWrapper (events.js:314:30)
It would appear the plugin is no longer working with the PurpleAir API.
[2019-11-9 07:56:42] ReferenceError: pmtoString is not defined at PurpleAirAccessory.updateData (/usr/local/lib/node_modules/homebridge-purpleair/index.js:155:54) at Request._callback (/usr/local/lib/node_modules/homebridge-purpleair/index.js:50:32) at Request.self.callback (/usr/local/lib/node_modules/request/request.js:185:22) at emitTwo (events.js:125:13) at Request.emit (events.js:213:7) at Request. (/usr/local/lib/node_modules/request/request.js:1161:10)
at emitOne (events.js:115:13)
at Request.emit (events.js:210:7)
at IncomingMessage. (/usr/local/lib/node_modules/request/request.js:1083:12)
at Object.onceWrapper (events.js:314:30)