I’m looking for a basic motion sensor (ideally IR, so it’ll work in the dark) that will simply send me a text when it sees something. Lots of them out there, but they all seem to require some larger scale control panel. I want something small, battery powered. Would prefer to stay under $20. Recommendations?
So I assume you don’t have Home Assistant running somewhere? If you do the answer is fairly trivial, but otherwise it’s probably still doable with an ESP32, a PIR , wifi and a SMS provider account.
You could whip up something using ESPHome and a REST API SMS provider like Clicksend. You would need to be able to read and implement their REST API documentation, but all the software is standard on ESPHome.
What comms/protocols do you have installed, zigbee/wifi/433/zwave/etc.? And where would the sensor be, can you be sure it is within range of the receiver?
The price depends on that too
I have active wifi and Bluetooth. Am using Sonoffs regularly, so eWeLink is active. I just want to buy something cheap, and if necessary, download an app that can connect to it. I’m looking at the Senckit WiFi PIR Motion Sensor. That might do the trick. Needs the Tuya or Smart Life app.
You would want that HA connects directly to the device, only very (!) few people are OK with Tuya or have no choice depending on the device, most people will tell you to steer away ( I kicked all Tuya-crap out due to loss of connection and other &^%@#).
If you think to expand into more devices I personally would recommend to add a zigbee range to your HA, the dongle is not that expensive and line-powered devices act like a mesh…also the devices are not that bad on price, a bit more than wifi but imo worth it.
On wifi, my (me) option would be to go for esphome but this may be a step too far for you (donot know your tech level)