3 ms·
If I recall, they have female port connectors on the bottom and little male prong connectors that mate with them on top. I assume that is mainly for power conne
by jrussino 2y ago
If I recall, they have female port connectors on the bottom and little male prong connectors that mate with them on top. I assume that is mainly for power connection, so you can put a whole stack on a charger and charge them all simultaneously. But if they can sense a signal on the female pins then that's sufficient to enable the behavior you're describing without directly knowing the positions of each pager, right? Pager on the bottom sees a signal on its female pins, blinks its light, send the signal on its male pins, then the next pager above sees the signal on its female pins, blinks its light, sends the signal on its male pins, etc...
- Cerium 2y agoI think that is the whole trick - they look like they are all in parallel on four wires, but really two of the wires are daisy chained through each device (like serial LEDs). In this configuration you can do the light tricks without knowing the order, but you can also enumerate the order. I have seen addressing based on hop counting, or by appending your ID to "who are you" message. Eg: Host sends "who are you" first device appends an ID number and then propagates the message forward in the chain. Each device does the same, until the last device in the chain (which detects electrically or via a timeout that there are no more devices) decides to loop the message back to the host.